The Chemist's Kitchen

Potomatatoes & Acidity

2012-01-14T12:10:00.000+11:00

Anonymous asked "Do totatoes can acidity in the body?"

Well, that is not an easy question to answer, as such.

Are we talking potatoes or tomatoes?
Are we talking cancel or cause?

Never mind - I'm guessing that it relates to the much discredited acid-alkaline diet that lingers in the fringe diet circles. In essence, it proposes that foods are good or bad depending on the pH of a solution of the ash of the food. The notion that the acidity or alkalinity of the ash of a food will influence the impact that the food has on your body is just plain weird.

There is no scientific data to support the theory. There is not even a coherent theory.

Your stomach is already 100-1000 times more acidic than a tomato or a potato, so any native acidity will have a negligible impact. No foods are natively alkaline.

As you body never reduces food to its ash, the properties of the ash are immaterial to human nutrition.

Eat a varied, balanced diet.
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Cancer and spices.

2011-12-14T20:12:00.000+11:00

Anonymous asked: "Do ginger, curry powder and cumin powder help reduce risk of any cancers? "

Disclaimer: I am a food chemist and any medical comments are those of a food chemist.

Will anything prevent cancer?

No, probably not. Cancer is not one disease but a diverse group of illnesses, all characterised by uncontrolled cell growth. Cancerous cells are being produced all the time and the body deals with them. The problems arise when the body can no longer deal with them. This will be partly why cancers are more prevalent in the elderly; the body’s defences get weak, lazy or ineffective.

I believe that pretty much anything will cause cancer – if the body gets swamped with any chemical, systems can go awry.

But will anything prevent cancer? I don’t believe so. At least not any one thing.

Good diet and good health seem to be part of the cancer preventative thing : be healthy, give your body a chance. Let your body function as it should, defences work properly, cell reproduction work reliably.

I have little doubt that the individual components of ginger, cumin and curry powder will trigger cancers if taken in excess. Anything taken at a level that distresses the body increases the likelihood of the body malfunctioning and cancers being the result.

But I really have no knowledge on compounds, natural or synthetic, that may directly work to prevent cancers. And I think it unwise to pin your hopes on a 'silver bullet'.
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Take it with a pinch, no, a bag of salt!

2011-10-30T20:31:00.004+11:00

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Food Australia, who should know better, published an article earlier this year titled "Contaminated reusable grocery bags pose health risks" (63 (5) - May 2011). It was based on an article by Gerba & Sinclair entitled "Assessment of the Potential for Cross Contamination of Food Products by reusable Shopping Bags". You can download the full article here.

The article suggests bacteria, including E. coli, flourish in the green bags.

And the are probably right. The same way bacteria can flourish in pretty much any environment. Because bacteria is IN the environment. If they had done their survey by swabbing the jeans of the shoppers rather than the bags, they would have got similar results.

And as for soaking the shopping bags in meat juices and leaving them in a car boot (trunk) for two hours - well, duh!, of course bacteria levels will increase.

It was all a bit odd and I had a niggling suspicion, which is why I chased down the original article rather than relying on the summary in Food Australia. My suspicion was confirmed in the following line:

"The authors would like to acknowledge and thank the American Chemistry Council for providing funding to support this study."

So, the American Chemistry Council, a body that includes all the plastic (bag) manufacturers of America in its ranks funded the research.

Doesn't mean it's wrong but there are flashing lights all over it!
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Not ducking the question.

2011-08-29T20:24:00.004+10:00

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Celia of Fig Jam & Lime Cordial, asks

"I've been making confit duck, and keep it for a short time in the fridge.

1. As instructed, I've been reheating the used duck fat to clarify it and then storing it in the freezer to be reused next time - is this a safe practice, and how many times can the fat be reheated and reused like this, please?

2. Secondly, confit duck (a traditional food) has been stored for generations by the French on the pantry shelf, with some instructions going so far as to say "don't worry if the bones not covered in fat go a bit green". I don't do that, I keep it in the fridge, but wondered whether it was actually safe to store meat like this unrefrigerated?

Question 1. It is a matter of taste. Over time there is a likelihood that the fat will start breaking down but that in itself is not harmful. The issue is whether the taste is affected. My Granny had a 'dripping pan' that used to hold fat that was returned time and time again to the weekend roast, with no ill-effect. Animal fats are generally too saturated to have oxidative rancidity and hydrolytic rancidity (the splitting of the fatty acids from the glycerol backbone of the fat) often cannot be tasted. A text book I read once famously said that a fat was rancid if it tasted rancid and that all other tests were, at best, just corroborating evidence.

The splitting of the triglyceride happens during digestion so it is no a health hazard as such.

So, in short: as long as the fat still tastes ok, it is fine.

Question 2. The fat layer is supposed to keep the meat protected. Despite what advertisers of disinfectants and such like would have you believe, bacteria do not spontaneously appear for no good reason. This is a habit solely retained for the start of a new Universe. If your duck is cooked, it will be sterile and the thick layer of fat will keep it sterile.

Has done so safely for many many years.

Green is more problematic but not necessarily harmful. The pigments in blood - haemoglobin and myoglobin, will oxidise and go funny colours, mostly green, grey and brown, with exposure to the air. Unsightly but not harmful. The surface of the chicken paté I make discolours quite quickly but is not harmful.

More important is to make sure that the exposed bones and such like are not handled as they do not have the layer of protective fat and will possibly give bacteria a toe-hold.
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Stamps. And the perils of licking them.

2011-08-21T14:53:00.006+10:00

Stamp commemorating all that was left standing after the US 'liberated' Iraq?

Xink asks: Is it possible to die from licking stamps? As in the Seinfeld episode when George Costanza's fiance dies after licking cheap stamps for a wedding invitation mail out.

Good grief - we get further and further away from food chemistry!

Partly my own fault: My profile has a question on it: "What's the best time you've ever had licking stamps?" My response was "Ah, Stamps! Such a lovely girl. So many memories; how can I choose?" So I guess I have no-one to blame but myself.

The short answer is that I do not know of anyone dying from licking stamps but the mucilage that was put on stamps to act as the adhesive is a protein based material and, as allergenic reactions are generally a response to proteins, it is not impossible that someone may have a reaction.

◊◊◊

As for the Stamps of my profile. Yes, if her boyfriend found out, that could kill you.

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The Hormonal Cow

2011-08-04T21:00:00.004+10:00

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Celia asked: Lee, do you have any thoughts about growth hormones in Australian beef and what they're doing to us?

Well, yes, I have thoughts. Mixed thoughts.

I don't have too many facts, though, as it is a bit outside my experience.

Thoughts, in no particular order:

1. I have a general preference for no additives in food (don't you dare call them 'chemicals' unless you can name one thing on this planet (and beyond) that is not composed of chemicals) however I accept that sometimes additives to food are unavoidable.

2. The Safemeat site suggests that hormones are not harmful but that, while they increase meat yields, they decrease meat tenderness. This site is a joint venture between the meat industry and the Government.

3. Talking to another laboratory that tests HGP (Hormone Growth Promoters), they can only reliably find them in the area surrounding the injection point in the cow's ear. In other parts of the body they are too low to quantify.

4. Like it or not, we must increase our food production to meet the population growth; farmland is decreasing, so per-acre yields must increase. But we eat too much meat per meal, as a rule.

5. There is little evidence available to show that the nature-identical hormones are harmful. I am probably more comfortable with them than I am with the fully synthetic ones.

6. I would favour mandatory labelling.

So, in summary, I don't think they are harmful but would prefer they not be used.

But I am no expert.
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Steak Tartare

2011-07-20T20:10:00.003+10:00

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Celia, of Fig Jam & Lime Cordial, asked "Does the traditional food rule apply to dishes like steak tartare?"

Yes, is the short answer.

Steak Tartare is a traditional food.

Despite the rantings of Professor A. C. Grayling, philosopher and vegetarian irrationalist, meat is not full of bacteria. (See here) Once you cut it, though, bacteria is introduced and the life of the meat starts being reduced.

A number of things need to be remembered:

The amount of bacteria that you introduce in chopping the meat is quite small. Especially if you take care to use clean knife.
Bacteria, at room temperature, will double in numbers every 20min, so what starts out as a low level can rise very quickly.
Most spoilage bacteria is just that, spoilage bacteria. Pathogens, such as E-coli or Salmonella, are less prevalent and less likely to be introduced in the chopping of the meat.
The concept of an 'infectious dose'. Everyday we are ingesting low levels of bacteria, including pathogens, with no ill effect. There is a certain level that is necessary to induce illness.

The long and short of it is that Steak Tartare must be made fresh and eaten fresh.

That is the traditional way to do it.

And it is quite safe.
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Sunscreens, SPF 50

2011-07-17T18:59:00.006+10:00

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Much excitement in Australia this week with the granting of permission to sell SPF 50 sunscreens.

Got to be 66% better than all those SPF 30 ones, mustn't they?

Well, hold you horses. Could it just be marketing hype?

To get the SPF factor, you divide 100 by 100 minus the percent of the UV radiation blocked.

So if a sunscreen blocks 90% of the UV light, its SPF is 100/(100-90) = SPF 10.

95% = SPF 20

97% = SPF 30+

98% = SPF 50.

So paying the extra money for an SPF 50 sunscreen will increase your protection by just 1%.

If (IF!) it is re-applied regularly and applied at the same thickness as is used in the test (0.1mm).

T-shirts and a hat have a higher SPF factor.
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Smells dead, must be dead.

2011-03-22T19:47:00.005+11:00

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Chairman Bill asked: "How about trassi? I've heard some hideous stories about it, although I've eaten plenty of it in my time (both as a Dutchman and when in Indonesia/Malaysia)"

This is an amazing fermented dried shrimp paste that smells awful but tastes wonderful.

The big thing is that this is a traditional food; a pretty reliable sign of a good track record for safety.

And the traditional way of cooking it is to stir-fry in a very hot wok. This will kill any bacteria that may be in it. Deviate from traditional cooking processes at your peril.

It must also be remembered that it is usually a dried product and so lacks the available water needed for bacterial growth.
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Of meat and fridges...

2011-03-21T20:02:00.004+11:00

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The Intolerant Chef asks: "How long can raw meat be kept in the fridge before being harmful? I remember my mother washing slightly bluish looking chops in vinegar and water to remove the stickiness and smell before cooking them. They were then fed to my father, never us children or her."

I assume your father was well insured.

Generally, fresh meat can only be kept for a few days at refrigeration temperatures. It is hard to butcher meat without getting bacteria on its cut surface and bacteria love a warm, protein rich surface.

Note: these are bacteria introduced during the butchering process and not endemic to the meat as such. When the meat is 'hung' after slaughter, the surface of the carcass is dry and intact and no bacterial degradation takes place. Once the meat is sliced or minced, bacteria is introduced and all bets are off.

Chilling meat slows bacterial growth but doesn't stop it. Freezing it stops the growth. As does drying.

Bacterial growth results in the breakdown of proteins which in turn produce the unpleasant smells that we associate with 'off' meat. Rubbing the meat with vinegar may reduce the bacterial load and reduce the smell. Traditionally curry was also used to hide off meat.

It would be the thorough cooking afterwards that killed the bacteria and made it safe for your father to eat.

Probably with lots of sauce.
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The Mayo Clinic

2011-01-21T20:22:00.005+11:00

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Don says:

"I had the wonderful privilege of touring Mullins Food Products, Makers of mayonnaise.. "(Mayonnaise) doesn't even have to be refrigerated. No harm in refrigerating it, but it's not really necessary." He (the food chemist) explained that the pH in mayonnaise is set at a point that bacteria could not survive in that environment.

(The food chemist) says that when food poisoning is reported, the first thing the officials look for is when the 'victim' last ate ONIONS and where those onions came from (in the potato salad?). Ed says it's not the mayonnaise (as long as it's not homemade Mayo) that spoils in the outdoors. It's probably the onions, and if not the onions, it's the POTATOES.

He explained, onions are a huge magnet for bacteria, especially uncooked onions. You should never plan to keep a portion of a sliced onion. He says it's not even safe if you put it in a zip-lock bag and put it in your refrigerator. "

Ye gods! Where do I start?

The easy bit first: see a previous post on the myth of onions being bacteria magnets. Make sure you read the comments, as the saga went on for a while.

Secondly, there is a popular myth (only in the US for some reason) that mayonnaise is a chief culprit in food poisonings. It isn't. Or at least commercial mayonnaise isn't, as it is made in strictly controlled conditions.

The pH of mayonnaise is kept low, at a level that bacteria cannot survive.
The water activity of mayonnaise is low, meaning that the moisture present in the mayonnaise is not available to the bacteria (or mould) to use and
the product is made in sterile conditions.

The consequences of that last item eludes many people. They think that bacteria just happen. That is as sensible as watching a field, hoping for corn to grow. If you don't plant it, it wont grow.

And "if not the onions, then the potatoes"?

Anything that grows in dirt can have bacteria on it. It will be in an environment where there is E-coli, Salmonella, Clostridium, lots of bugs with long and threatening names. Wherever birds poop and animals roam will have bacteria. You meet up with them every day of your life. And survive.

But if you take some potatoes and cook them there will be no bacteria alive on them.

Put them in a potato salad with mayonnaise and they will still have no bacteria on them.

The biggest problem is when you add bacteria to the salad yourself and then leave the salad sitting unrefrigerated for hours on end. At room temperature bacteria multiply tenfold an hour.

So where do these bacteria come from? Spices, raw unwashed vegetables and, most commonly, poor personal hygiene when preparing the food.

But from the mayonnaise? No.

From onions? No.

From cooked potatoes? No.
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Of camels and straws and chocolate

2010-12-13T20:22:00.007+11:00

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Really, the picture is just there because it is pretty.

This post has nothing to do about camels, a little to do about straws of the sort that worry camels but nothing to do with drinking straws but a little to do with chocolate.

But most to do with dieting and perspective.

Many moons ago we had a receptionist who seemed, like most women, to be on a permanent diet. To reward herself for her calorific restraint she treated herself to a 50g (2oz) chocolate bar every day as part of her lunch.

50g of chocolate. Every day.

Doesn't seem much until you multiply by 365.

That's over 18 kilograms of chocolate a year. Nearly 40 pounds of fat and sugar a year.

Surely her diet would do better if she didn't eat the chocolate.
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Eating eggs in summer.

2010-12-12T20:03:00.002+11:00

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I've been AWOL from this blog for a while. So much so that Joy Vazapully, who posted the following question, has disappeared from the blogland. I hope the eggs didn't get her.

Joy's question was: "There is a belief that one should not eat eggs in summer, do you think there is any reason?"

The short answer is no.

The longer answer is that, if they affect you in any way, don't eat them but apart from that no.

I know of no reason to be wary of eggs in summer. Obviously normal handling rules apply and you should be aware of the issue of temperature abuse and bacterial growth but that is a normal food hygiene issue and not specific to summer as such.
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Coming back for (five) seconds - The Five Second Rule

2010-07-25T17:58:00.008+10:00

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I can't believe some people - I only recently caught up with the supposed Five Second Rule and it is just bizarre.

In essence, it says that if you drop something on the floor, you have five seconds where it is safe to pick the food up. It implies that bacteria wont hop onto the food in that time.

Sure.

Now, if it is a crisp (above) there will be minimum contact with the floor and most respectable bacteria would not worry about trying to live on a crisp anyway.

But what if it is a swab the surgeon is going to use on (in!) you in an operation? Still so sanguine?

The more sloppy the food, the more likelihood of bacteria hopping on board as it makes better contact with the floor.

But there are some provisos:

1. If the food is really sloppy it will leave a layer on the floor and there will not be much or any transfer onto the food.

2. The other issue is the one of what is known as the infectious dose. Sure some bacteria will get on the food but there will not be enough to make you sick unless you put it somewhere to grow the numbers a bit. eg too it into the salad you are making for lunch in three hours time.

3. What about interesting things like worm eggs from your dog, cat, hamster? (Erk!)

I'll drink to that!

2010-05-16T19:40:00.003+10:00

You are not going to want to read this: chocolate cannot be relied upon as a source of antioxidants to boost cardiovascular health. But it gets worse: drinking coffee and red wine in the hope it will prevent heart disease doesn't work either.

- The Age Newspaper.

Why am I not surprised?

Have I not said from day one (of this blog) that there are no silver bullets?

Note: I do have to be careful - the reports in the media are exactly what I expected to be the case so the temptation to be uncritical is high.

But really why should anything be a silver bullet? We, as animals, have evolved along with the plants. Some we have leant to eat safely. Some we have learnt will kill us and should be avoided. True, there may be some plants which have beneficial properties but it is pure fluke and certainly there is no reason to think that, if a little is beneficial, a lot will be more so.

Even red wine.
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Revisiting Alfalfa Sprouts

2010-02-15T20:43:00.003+11:00

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Pythagorian asked: I read your warning about alfalfa sprouts and wonder how and what bleaching methods you recommend. Also I have read a claim that there has never been a case of sprout contamination traced to certified organic sprouts. Do you know if this is true or false?

The common commercial process is shock chlorination of the seeds and chlorination of the water.

The organic claim will be false. The main issue is you have a protein-rich food source that you are keeping wet and warm for several days. Any bacteria present will thrive. This has nothing to do with the organic status of the food, bacteria is naturally present in the environment. In some ways organic produce may have more bacteria. This is not a bad thing, just a consequence of things growing in the open.

Chlorination will kill the bacteria. Other processes might too. My observation is that there is not much margin for error. Warm and wet, bacteria will double in numbers every 20 minutes and most sprouts are eaten uncooked.

The Chinese eat lots of sprouts, without problems, but they stir-fry them and this kills the pathogens.
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Blowers vs Towels

2010-01-30T11:53:00.006+11:00

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This is more microbiology than chemistry but it has been a subject that fascinated me. Electric hand dryers in public toilets have long been touted as more hygienic than paper towel.

Not so, it seems.

[Wikipedia] In 2008, a study was conducted by the University of Westminster, London, to compare the levels of hygiene offered by paper towels, warm air hand dryers and the more modern jet-air hand dryers .

The key findings were:

after washing and drying hands with the warm air dryer, the total number of bacteria was found to increase on average on the finger pads by 194% and on the palms by 254%
drying with the jet air dryer resulted in an increase on average of the total number of bacteria on the finger pads by 42% and on the palms by 15%
after washing and drying hands with a paper towel, the total number of bacteria was reduced on average on the finger pads by up to 76% and on the palms by up to 77%.

The scientists also carried out tests to establish whether there was the potential for cross contamination of other washroom users and the washroom environment as a result of each type of drying method. They found that:

the jet air dryer, which blows air out of the unit at claimed speeds of 400 mph, was capable of blowing micro-organisms from the hands and the unit and potentially contaminating other washroom users and the washroom environment up to 2 metres away
use of a warm air hand dryer spread micro-organisms up to 0.25 metres from the dryer
paper towels showed no significant spread of micro-organisms.

And, yes, the work has been replicated.
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Potatoes

2010-01-10T14:56:00.002+11:00

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When I worked at the Coroner's Court, I remember reading about a guy who had a whole lot of potatoes that had started to shoot and so he broke off all the shoots and stir-fried them.

May he rest in peace.

There is a toxic alkaloid called Solanine that is produced by shooting potatoes. It is very high in the shoots and is also high in the potato when it has a green skin.

This calls into question the ethics of supermarkets who sell potatoes in pink plastic bags, or under pink lighting, as it makes the green potatoes look brown.

Until you get them home.
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The red coats came.

2009-12-28T11:20:00.004+11:00

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It is hard to believe that these little tackers, small scale insects on a South American cactus, are useful but they are the source of the common food colour, Cochineal.

The very same colour responsible for the original red coats of the British army:

It takes some 70,000 of the little critters to make a pound of dye.

There are two principal forms of cochineal dye: cochineal extract is a colouring made from the raw dried and pulverised bodies of insects, and carmine is a more purified colouring made from the cochineal. To prepare carmine, the powdered insect bodies are boiled in ammonia or a sodium carbonate solution, the insoluble matter is removed by filtering, and alum is added to the clear salt solution of carminic acid to precipitate the red aluminium salt. Purity of colour is ensured by the absence of iron. Stannous chloride, citric acid, borax, or gelatin may be added to regulate the formation of the precipitate. For shades of purple, lime is added to the alum.

-Wikipedia

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Is Coca Cola evil?

2009-12-13T09:50:00.005+11:00

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Got an email from a friend recently, spouting the old and hoary myths about Coca Cola. My comments are in blue.

1. In many states the highway patrol carries two gallons of Coke in the truck to remove blood from the highway after a car accident.
Why would they? Water is cheaper and as effective. But don't take my word for it - as a patrol man. But be ready to be laughed at.

2. You can put a T-bone steak in a bowl of coke and it will be gone in two days.
No, it wont. But don't take my word for it. Put a piece in Coke and watch it get wet and soggy before you eyes. But it wont dissolve. Only use a small bit, no sense in marinading a whole steak.

3. To clean a toilet: Pour a can of Coca-Cola into the toilet bowl . . . Let the "real thing" sit for one hour, then flush clean.
Probably will. It is a weak acid and the stains are generally acid soluble. So what. Orange juice would probably do the same.

4. The citric acid in Coke removes stains from vitreous china.
See 3, though Coke is more commonly phosphoric acid.

5. To remove rust spots from chrome car bumpers: Rub the bumper with a crumpled-up piece of Reynolds Wrap aluminum foil dipped in Coca-Cola.
See 3.

6. To clean corrosion from car battery terminals: Pour a can of Coca-Cola over the terminals to bubble away the corrosion.
Again, so what? Any carbonated drink will do this. Best use soda water so that you don't get a sticky battery.

7. To loosen a rusted bolt: Applying a cloth soaked in Coca-Cola to the rusted bolt for several minutes.
Never managed to get this to work myself. Eucalyptus Oil works a treat, though.

8. To bake a moist ham: Empty a can of Coca-Cola into the baking pan;rap the ham in aluminum foil, and bake. Thirty minutes before the ham is finished, remove the foil, allowing the drippings to mix with the Coke for a sumptuous brown gravy.
Yum. Is this a bad thing?

9. To remove grease from clothes: Empty a can of coke into a load of greasy clothes, add detergent, And run through a regular cycle. The Coca-Cola will help loosen grease stains. It will also clean road haze from your windshield.
Most detergents are phosphate based. So is Coke. Is there enough phosphate to act as a detergent? It certainly can't hurt.

FYI: 1. The active ingredient in Coke is phosphoric acid. It's pH is 2.8. It will dissolve a nail in about 4 days.
No it wont. I tried it and the nail was still there 4 years later. Ditto a copper coin.

The pH of your gastric juices can be as low as 1. That's six times stronger than Coke.

2. To carry Coca Cola syrup (the concentrate) the commercial truck must use the Hazardous material place cards reserved for Highly Corrosive materials.
Your point being? The same applies to trucks carrying vinegar concentrate.

3. The distributors of coke have been using it to clean the engines of their trucks for about 20 years! Drink up! No joke. Think what coke and other soft drinks do to your teeth on a daily basis. A tooth will dissolve in a cup of coke in 24-48 hours.
Any carbonated soft drink will help dislodge muck from anything. It's the bubbles what do the job.

Teeth? Nope, sorry. Not enough acid in the drink to do that.
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A rum deal.

2009-11-21T16:11:00.003+11:00

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People are funny critters.

I was telling someone last night that I was going to sprinkle some brandy on my Xmas cake and they responded with "With my cake, two slices and you can't stand up".

Really?

Another friend swears that, after two of her sister's rum balls, you will not be able to drive.

Have they thought this through?

You need about 5 standard drinks to reach the legal limit to drive. I have done a few searches of rum ball recipes and the typical level of rum is about 5%. More or less.

Now a standard drink is 30ml for spirits, so to get five drinks worth of rum under your belt you need to eat 3kg (6.6lb) of rum balls in a hour.

And to loosen your belt.

I'm thinking not.

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Halloween & the Chemist

2009-10-31T12:21:00.006+11:00

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It's Halloween and I thought a little bit about sulphur would be fitting as sulphur is the basis of brimstone and supposedly the smell of Hades is burning brimstone.

I have never seen as pretty a piece of sulphur as that above, apparently it grew in a volcano. Usually, sulphur is a yellow powder. Dull.

Sulphur is the basis of one of the most common food additives, the preservative sulphur dioxide. Which used to be created by burning sulphur.

Still is in Hell, we are told.

Below is a small video on sulphur put out by the University of Nottingham. Like all good chemistry videos, it has explosions in it.

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Done to a tea.

2009-10-18T12:42:00.004+11:00

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Interesting story about tea recently:

A 44-year-old man presented in May, 2001, with muscle cramps. He had recently switched to drinking Earl Grey tea in preference to his regular black tea.

One week after the change, he noticed repeated muscle cramps for some seconds in his right foot. The longer he drank Earl Grey tea, the more intense the muscle cramps became. After 3 weeks, they also occurred in the left foot...

Earl Grey tea is composed of black tea and the essence of bergamot oil, an extract from the rind of bergamot orange (Citrus aurantium ssp bergamia), which has a pleasant, refreshing scent.

(You can skip this paragraph, if you wish) The adverse effects of bergamot oil in this patient are explained by the effect of bergapten as a largely selective axolemmal potassium channel blocker, reducing potassium permeability at the nodes of Ranvier in a time-dependent manner. This may lead to hyperexcitability of the axonal membrane and phasic alterations of potassium currents, causing fasciculations and muscle cramps.

In other words, it disrupts the way chemicals flow through the membrane of the nerve fibres, causing the neurons that connect to the muscles to malfunction.

I should add he was drinking four litres (a gallon, say) a day.

But it plays into my constant refrain: too much of anything is bad for you.

Food-wise, at least.
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Hot and cold on Cayenne

2009-10-11T12:38:00.005+11:00

medavinci asks "Is it true cayenne pepper can lower blood pressure and open arteries? Can you just sprinkle it on your food or should it be cooked like curry to avoid salmonella? "

OK, a two part question:

Part 1. Is it true cayenne pepper can lower blood pressure and open arteries?

Maybe. Certainly many foods have physiological effects. A peek on the internet finds a squillion and one sites selling the benefits of cayenne pepper (as well as selling the cayenne pepper) but I couldn't find any mainstream sites, just the herbal fringe. This always makes me suspicious. But I have no reason to doubt that it MAY affect blood pressure. In either direction.

Opening arteries is a little more serious. Certainly people can get flushed in the face after eating peppers, chillies and such like. Is the the same as 'opening arteries'? Maybe. Is it desirable to look flushed? Possibly not. Is it the same as unclogging arteries from too many fries over a lifetime? No.

Maybe it works, maybe it doesn't. By the time you find out, the purveyors of fine herbal remedies will be telling you to eat, drink, roll in something else. But, if you feel that it is good for you, then it is. Isn't it?

Do be aware of the possible risks associated with cancers, especially mouth cancers, from excessive and prolonged consumption of irritants like chilli and pepper.

A rule of thumb that I always have with herbal remedies (like the one in this morning's paper that said magnolia flower tea cures hayfever) is a very simple question: if this cure, cayenne pepper, is so good and so effective, why are the major pharmaceutical companies not growing broad-acres of the stuff? These guys are pretty keen to corner the consumer dollar and never slow to see an opportunity.

Could it be that the efficacy of cayenne hasn't been proved to the level of certainty required by good science and the auditors of the Therapeutic Goods Act?

Remember: Alternative medicine that works is called... medicine.

Part 2: Can you just sprinkle it on your food or should it be cooked like curry to avoid salmonella?

If you are consuming it immediately it will be safe to take 'raw' as it were. If you are putting it into something warm, moist and nutritious and not planning to eat it for a few hours, cook it first.

Monosodium Glutamate

2009-10-04T20:53:00.007+11:00

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MSG gets a bad press. Not entirely sure why, as the stories about it are largely unproven.

No uncommonly you will see products claiming 'no MSG'.

Or restaurants with the same sign. No MSG.

They are misleading you folks. What they mean is 'No Added MSG'.

You see, for all its bad press, MSG is naturally occurring in most foods, especially the following:

Meat
Fish
Cheeses, especially hard cheeses like parmesan
Tomatoes and tomato juices, concentrates and sauces
Stocks cubes and concentrates
Sauces such as soy, fish, oyster etc
Spreads such as Vegemite®, Promite®, Marmite® etc.
Foods containing added Hydrolyzed Vegetable Protein (HVP)
Mushrooms
Corn
Peas

And Human breast milk.

Glutamate is produced by the human body and is vital for metabolism and brain function.

Enjoy.
...

French Dressing

2009-09-20T20:11:00.004+10:00

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French dressing is one of the classic salad dressings.

Mine is typically made 'by eye' rather than recipe but, in essence, is as follows:

50ml cider vinegar
200ml olive oil
Crushed garlic, to taste
Qtr teasp mustard powder
Salt & Pepper.

So, for a product that is about 80% oil, how do the Krafts of this world explain the culinary obscenity that is "Fat Free French Dressing"?

Sure, it is a 'salad dressing' but why not call it what it is 'Sweetened, jellied vinegar"?

It's not French. And it's not right.

...

Alcohol & Mouth Cancers.

2009-09-05T14:04:00.004+10:00

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A local news outlet ran with a story recently that said research had shown that increased alcohol consumption lead to increased mouth cancers.

The trail to try to find the supporting research lead back to a UK cancer body but a request for a reference went unanswered.

The report (SBS News) said that over the last 30 years alcohol consumption had gone up and so had the incidence of mouth cancers. Ergo, drinking increases your chances of mouth cancer. The stated increase was 25%.

Sounds scary. But what if the chance had gone from 1 in a million to 1.25 in a million.

Not quite so scary.

And what else has changed over the last 30 years with things that go into people's mouths?

The Western diet has dramatically increased its consumption of chilli, a known mouth irritant.
Much more processed food.
Much more junk food.
Many more novel food additives, such as artificial sweeteners.
Vegetable consumption has decreased.
Fruit consumption has decreased.
Oral sex has, anecdotally, increased. (human papilloma virus (HPV), is a known carcinogen.)
Beer consumption down, wine consumption up.
Genetically modified foods introduced.

To mention just a few.

I will take their survey just a little more seriously when they can tell me how they allowed for these other changes.

And who paid for the research. And why.
...

Nutmeg

2009-08-24T20:55:00.007+10:00

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Most people know of nutmeg, a common spice. Goes well in eggnog and such like.

What most people don't know, and continues my theme that everything is bad for your and laboratory rats at some level, is that nutmeg is toxic. Certainly if you applied to have it approved for use as a new drug you wouldn't get it past the food authorities.

We had a fruitcake submitted due to a complaint that the consumer's lips tingled when she ate the cake. Was it contaminated? No, but it had high levels of nutmeg.

Wikipedia says of nutmeg toxicity:

In low doses, nutmeg produces no noticeable physiological or neurological response.

Large doses can be dangerous (potentially inducing convulsions, palpitations, nausea, eventual dehydration, and generalized body pain).

Users report both negative and positive experiences, involving strong hallucinations, and in some cases quite severe anxiety.

Use of nutmeg as a recreational drug is unpopular due to its unpleasant taste and its possible negative side effects, including dizziness, flushes, dry mouth, accelerated heartbeat, temporary constipation, difficulty in urination, nausea, and panic. In addition, experiences usually last well over 24 hours making recreational use rather impractical.

Good reason to cut back on the nutmeg and up the rum.
...

The criminal mind

2009-08-23T11:48:00.003+10:00

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There was a newspaper item this morning about police in the US finding a body. It was disfigured and minus fingers and teeth, to avert identification.

But first a diversion...

I used to work at the coroner's court labs in Melbourne. People would drown someone in a bath tub and then throw them into the sea, not realising that we looked at the water in their lungs to see if they drowned at sea. They would kill someone and then burn the house down, not realising that we looked at the blood for evidence of the carbon monoxide poisoning that would be present in a fire victim and absent if they where dead before the fire started.

I used to work looking at foreign matter in food. We could often tell if the object was in there before cooking or entered after, either by accident, sabotage or extortion. Insects, for example, have an enzyme called phosphatase which is destroyed by cooking. If you must slip a cockroach into a pizza, cook it first.

Time and time again, people wanting to commit a crime, big or small, overlook something quite basic.

Back to our anonymous lady...

The police identified her by the serial numbers on her breast implants.
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Radioactive Calamari

2009-08-20T21:22:00.004+10:00

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Every so often we get stories that go along the lines of :

"I went out to the kitchen in the middle of the night to get a glass of water. I didn't turn the light on and I saw the food in the cat bowl was glowing!

Is it radioactive?"

Most spectacular when it is calamari rings.

No, it is not radioactive, it is just active. With bacteria.

Pseudomonas fluorescens. A common spoilage bacteria that secretes a fluorescent pigment. It is generally harmless to humans unless they are already immunocompromised.
...

...

A little more on garlic...

2009-08-20T21:13:00.003+10:00

.

While we are on the topic of garlic, I was presented with a complaint once where the lady had mixed chopped garlic with lemon juice and microwaved it.

It turned bright green.

Some months later I was shown a bottle of garlic cloves, preserved in vinegar, that had similarly gone bright green.

What's going on?

Part of the problem is that this is not how garlic was traditionally treated. It would normally be cooked in a neutral sauce. And a thick sauce that hid it from view.

The two complainants were treating garlic in a a totally different way to normal.

But the reactions were perfectly normal.

Garlic has natural levels of iron and natural levels of sulphur compounds. Heated in the presence of an acid (lemon juice or vinegar) these compounds react to form iron sulphide which shows as a green colour.

Harmless.
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Of vampires and garlic.

2009-08-19T19:40:00.004+10:00

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"Vampires are feared everywhere, but the Balkan region has been especially haunted. Garlic has been regarded as an effective prophylactic against vampires.

We wanted to explore this alleged effect experimentally.

Owing to the lack of vampires, we used leeches instead. In strictly standardized research surroundings, the leeches were to attach themselves to either a hand smeared with garlic or to a clean hand. The garlic-smeared hand was preferred in two out of three cases (95% confidence interval 50.4% to 80.4%). When they preferred the garlic the leeches used only 14.9 seconds to attach themselves, compared with 44.9 seconds when going to the non-garlic hand (p < 0.05).

The traditional belief that garlic has prophylactic properties is probably wrong. The reverse may in fact be true.

This study indicates that garlic possibly attracts vampires."

Tidsskr Nor Largeforen. 1994 Dec 10;114(30):3583-6.: .

A troublesome crystal

2009-06-21T18:02:00.003+10:00

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A while ago we were talking about kidney stones. One of the variety of things that kidney stones can be comprised of is Struvite. To the chemically inclined, it is ammonium magnesium phosphate.

But today I want to mention one of struvite's other incarnations.

Tinned fish.

Struvite crystals will grow in tinned fish, especially salmon. Looking for all the world like pieces of windscreen glass after a crash, the crystals will come in for testing as "glass found in a tin of fish".

But it is not glass. And it is not harmful.

Should you swallow some it will dissolve in your gastric juices.
...

Flavoured e-Cigars

2009-06-14T20:32:00.005+10:00

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Chairman Bill said "Instead of smoking, I vape in my e-cigar propylene-glycol with nicotine that has flavourings added - banana, vanilla, etc.

Of late I have been 'cutting' the e-liquid with BP glycerine to make it go further, which does tend to dry out the mucous membranes a tad. However, my question is about added flavourings.

Given the e-liquid is vaporised prior to inhalation, what chemicals that commonly appear in food flavourings should I keep well clear of. I believe caramel bungs up the works of the e-cigar due to the sugars, but I'm led to believe that food flavourings can also have some added chemicals that can undergo a transition when vapourised and could be dangerous.

Blowed if I know, Bill.

It's not that a particular flavouring is dangerous. I am assuming that they are not burnt in the normal cigar/cigarette sense. If that is the case, they are all dangerous.

If the vaporisation is not at a particularly high temperature, they should all be OK.
...

Kidney Stones

2009-06-07T20:50:00.004+10:00

Kidney stone crystals.

Kris Loves Chocolate asks: "Could there be any truth to drinking pickle juice to dissolve a kidney stone? "

First let me say that I am a food chemist, not a pharmacist. By rights, I have no right to answer medical questions and any answer is based more on logic than medical knowledge.

Now, having said that, let me say this:

Kidney stones are things that have deposited, crystallised, from your urine. There are several types of kidney stones, so no one thing will cure them all.

For something like pickle juice, basically vinegar, to dissolve them it would need to get past your stomach and intestinal system and have an influence on the composition of your urine. Not impossible, by all accounts something in cranberries makes the passage and has a remedial effect with regard to urinary tract infections. But I am not convinced that acetic acid, the acid in pickle juice, will do that. Most body fluids are pretty tightly controlled for their pH.

More plausible is that drinking more fluids may lower the concentration of the salts in the urine that lead to the stones and then they may redissolve.

May.

I see no reason why pickle juice cannot be this fluid but water would be more palatable.

For more informed information, visit the Mayo Clinic site.
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Do birds burp?

2009-05-26T20:17:00.004+10:00

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Chairman Bill asks "My son keeps wanting to feed seagulls with bread laced with baking soda. Does it blow them up?"

I don't think so.

See here.

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Grey Egg Whites

2009-05-17T20:41:00.003+10:00

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Anonymous asked "I whipped egg whites in a Kitchen Aid mixer bowl & they turned a greyish color with a grey liquid. What kind of reaction was that? And is it still safe to eat? "

I can't be sure about a Kitchen Aid bowl but whipping egg whites in an aluminium bowl will produce a grey result as small particles of aluminium are rubbed off the bowl by the beaters.

Safe? Probably but best to avoid it if you can.
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Alkaline Water

2009-05-17T20:35:00.005+10:00

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Anonymous (and Honest Abe) asked: "Can you comment on the current fad of drinking alkaline water. People are spending thousands of dollars on machines that use electrolysis to make alkaline water. I can't see how this is real, nor can I understand how any alkaline water could be useful in the acidic environment of the stomach. "

Well, no, not really, not much. The mouth is alkaline and the stomach is acidic. The advantage of this is that, having an alkaline mouth, your teeth don't dissolve.

Beyond that, I can see no advantage of alkaline water.
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Curry Powder

2009-04-13T20:00:00.003+10:00

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Sara asked about curry powder.

There is absolutely nothing wrong with curry powder. It has been safely used for many centuries, following time honoured and well proven practices.

But what if those practices are not followed?

First, let's look at what curry powder is. It is the ground mixture of spices, seeds of a variety of plants. Seeds that have been exposed to the environment. There is nothing abnormal in that but, because of their origin, the seeds that go into curry powder will bring with them a variety of organisms from the environment. Notably Salmonella.

Now, how is curry traditionally prepared? You heat oil in a pan and cook the powder in this oil. Ostensibly to 'bring out the flavour' but, by a happy coincidence, it also sterilises the powder. You then add meat, vegetables, whatever and continue with making your curry.

What happens if you deviate from this long proven, survival enhancing, cooking practice? What if you are a new age cook and make a curried pasta salad where you just mix the warm (!) pasta, mayonnaise, vegetables, cream and curry powder and stir? Nothing much if you eat it straight away. But bacteria will double roughly every 20min at room temperature; what if you make your salad early and leave it for a few hours before eating? Not a good idea - the salad is warm, moist and protein rich - happy times for the bacteria.

Because of the risk, spices are one of the few things that are permitted to be irradiated to sterilise them. But this does not teach people safe handling practices for a potentially dangerous food. People will just be ignorant of the dangers and at risk from spices that are not irradiated.
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Egg whites & Copper bowls

2009-04-06T18:27:00.004+10:00

Woodfired asked: Whisking egg whites to the correct stiffness seems to challenge many. There is plenty of advice about how to make your whites stiff. An old one, and one that seems to be supported by professional chefs, is to whisk them in a copper bowl. Can you think of any likely reason why this would help?

Well, no, I had no idea. I thought it may be related to bowl cleanliness as this can influence whipping of egg whites. So I went hunting.

The bowl you use makes a difference when you are whipping egg whites. When air is whisked into egg whites, the mechanical action denatures the proteins in the whites. The denatured proteins coagulate, stiffening the foam and stabilizing the air bubbles.

A copper bowl assists in creating a tighter bond in reactive sulfur items such as egg whites. The bond created is so tight that the sulfurs are prevented from reacting with any other material. Copper bowls produce a yellowish, creamy foam that is harder to overbeat than the foam produced using glass or stainless steel bowls. When you whisk egg whites in a copper bowl, some copper ions migrate from the bowl into the egg whites. The copper ions form a yellow complex with one of the proteins in eggs, conalbumin. The conalbumin-copper complex is more stable than the conalbumin alone, so egg whites whipped in a copper bowl are less likely to denature (unfold).

If the foam is overbeaten in a non-copper bowl, eventually the proteins become completely denatured and coagulate into clumps. There is no going back from the clumpy mess to nice foamy whites, so overbeaten whites are usually discarded.

A silver plated bowl will have the same result as the copper bowl. Drawbacks of the copper bowl include the expense of the bowl itself, as well as the fact that the bowls are difficult to keep clean. Copper contamination from the bowl is minimal as a cup of foam will contain a tenth of one's daily normal intake level.

Although the iron and zinc found in other metal bowls also form complexes with conalbumin, these complexes don't make the foam more stable.

Cream of tartar (potassium bitartrate) is an acidic salt that can be used to change the pH of the egg white to an acidic range by boosting the number of free-floating hydrogen ions in the egg white. This has the effect of stabilizing the foam, and is therefore an alternative to using a copper bowl.

References:
http://en.wikipedia.org/wiki/Egg_white
http://chemistry.about.com/od/howthingsworkfaqs/f/copperbowl.htm

Onions as bacteria magnets.

2009-04-06T15:59:00.010+10:00

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Pauline asked: there is an email circulating claiming that cut onions are "magnets for bacteria" and should never be stored for later use (even in the fridge for a few days) as they will cause food poisoning. True?

Snopes (here) rates it as "undetermined".

I am willing to go out on a limb and say "false".

Reason 1: Nothing is a bacteria magnet. Firstly, bacteria have minimal mobility. They usually travel in water droplets, if at all. Sneezes, for example. Moulds can release spores which get blown around but bacteria usually grows in moist environments and are slimy, making getting airborne difficult. Secondly, if there was such a thing as a 'bacteria magnet' it would be enormously useful in the medical field for drawing bacteria away from the ill and infirmed. Not such use has been made of onions.

Contact with unclean hands can introduce bacteria to new surfaces but they need a surface that will support growth, otherwise they will just stay there without multiplying or die.

Reason 2: Bacteria like moist, neutral environments. Not many acidic things grow bacteria. That's why vinegar is used for preserving. The surface of a cut onion is acidic due to the production of sulphuric acid (this is what makes your eyes water). There are some moulds that will tolerate acidic conditions and grow on onions but they are not high risk, they are visible, and any normal person would cut them off or ditch the onion.

Reason 3: High risk foods are usually high in protein and available moisture. Onions are low protein, verging on nil, and what moisture they have is contained in their cellular structure. The surface, as well as being acidic, dries soon after cutting and will not support bacterial growth.

Reason 4: If onions are attracting bacteria, where are they coming from? Somewhere else in your fridge? Perhaps it is time to clean the fridge.

Reason 5: In the 20 odd years I worked in a food laboratory, onions were never mentioned as even a suspect in a food poisoning case.

-------
Footnote: we did have some onions brought to the laboratory as a food poisoning complaint once. A guy had eaten them and ended up in hospital. Only problem was, they weren't onions.

They were daffodil bulbs.
...

A non-cancer mouse death.

2009-04-03T01:34:00.000+11:00

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One neatly sliced mouse. Too much bread killed him.
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The case for tougher rats.

2009-04-02T20:05:00.005+11:00

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Chairman Bill, in a comment to the last post, deemed hydrogenated fats to be carcinogens.

While I took some issue with the broadness of the statement, I do agree in a broader sense.

At a different level, I believe EVERYTHING causes cancer. You just need more of some things than others.

In a broad sense cancers occur when the body's systems are overwhelmed by a particular compound or radiation. Even shift work is implicated in cancers nowadays. It is a case of the body getting swamped in someway and losing the plot when it comes to cell growth.

Tests in the labs have shown that if you swamp a lab rat's diet with a chemicals it will develop cancers but, in order to speed up the process the labs feed the rats enormous amount of the compound being tested. If you want to see what they went through, make a mix of a food of your choice and include 5% saccharin. Inedible. Now do it all meals for an extended time. Unbearable. No wonder the poor rat developed cancer. But how does swamping a rat's genetic processes translate into the long term effect of low levels of a saccharin on humans?

Bill talked about trans fats in margarines but they are naturally occurring in most fats.

In low levels.

It is generally accepted that smoking causes cancer; this is due to the compounds in the tars. Theoretically these compounds are first cousins of the charring of any plant matter. Smoking marijuana is just as dangerous as tobacco in this sense - different psychoactive substances, same tar.

But burnt plant matter is common in our diet - browned meat, roasted coffee, toast, cakes, biscuits, fries/chips. All theoretically foreign and carcinogens.

I argue that all chemicals, taken in excess for extended time will swamp the system.

I also argue that the system is designed to cope with a multitude of chemicals that are naturally in our food. The analogy would be sand. If I drop a stream of sand on your shoulder, it will bounce off and not be a problem. If I drop a ton of sand on you all at once, it is a big problem.

It is all a matter of recognising and managing risk.
...

Margarine & Butter

2009-04-02T11:52:00.005+11:00

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Sara asked for a run down on Margarine.

Normally the image sold to us with margarine is like the one above.

Mother Nature at her most adorable best.

In reality, canola seeds, the main source of oil for most domestic margarine and a close relative of rapeseed and mustard seed, looks like this:

Wholemeal margarine

For convenience, I will limit myself to the manufacturing steps to make canola-based margarines. The process is largely as follows:

1. Grind the seeds and extract the oil using petroleum solvent, usually hexane. Remove as much as possible of the hexane from the oil. The oil at this stage is a greeny-brown colour and has a nutty odour.

2. Treat the oil with caustic soda to neutralise free acids and precipitate gums.

3. Heat the oil with clay to bleach it to a pale yellow colour.

4. Deodorise the oil to remove unpleasant tastes and smells – this is usually done with steam and vacuum.

At this point you have vegetable oil, as you would buy it in the shops. Now...

5. Heat the oil under pressure and heat with finely divided nickel and hydrogen gas to saturate the double and triple bonds in the oil and create a fat that is solid at room temperature. Attempt to minimise the production of trans fats while doing this. The product is now solid, white and bland.

6. Add about 20% water or milk plus emulsifier (typically lecithin) to keep the water-oil suspension stable.

7. Add flavours (usually milk and/or milk solids) to give taste. Salt may also be added.

8. Add vitamins A & D to fortify it.

9. Add colour to make it look more appealing.

10. Put a lid on it.

-----------

Margarine has the same fat content (80-85%) as butter.

Margarine has the same calories as butter.

Margarine use was widely adopted when someone said butter was bad. No-one stopped to wonder if margarine was good. It just wasn't butter and butter was bad. Presumably butter was bad because it contained cholesterol. Now the notion that dietary cholesterol is a problem has been largely discredited. The concern now centres on the saturated fats in the diet.

Butter does have higher saturated fat levels than margarine.

The other thing to be aware of is that there is table margarine and cooking margarine. Cooking margarine is used in the biscuit and cake industry and is a harder (more saturated) fat than table margarine.

Is margarine bad?
No, not bad in the 'avoid at all costs' sense but nor is it 'natural' in the way the advertisers and their sunny yellow fields would like us to believe.
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Locked away in a room full of celery...

2009-04-01T12:39:00.003+11:00

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I used to be intrigued by a story I was told as a kid, that hard boiled eggs use more energy to digest than they contain and so you loose weight if you eat them.

Sounded dodgy to me, even then. It implied that if you were locked in a room with nothing but water and hard boiled eggs, you would starve to death.

But apparently that is the case with celery.

The calories in food are a measure of energy content. For something we eat to be a source of "negative calories," it must provide fewer of these units of energy than we expend in consuming it. Yet everything contains calories, so at first this concept appears impossible.

Therefore, the hunt is on for ingestibles whose energy content is not released into our bodies because we humans lack the ability to break them down — it doesn't matter how many calories these goodies have, provided we can't extract them.

Cellulose in plants is one such substance: although it contains a goodly amount of carbohydrates, they are packaged in a form we cannot digest, so we fail to absorb their calories.

Celery has about 6 calories per 8-inch stalk, making it a dieter's staple.

Its ingestion can result in negative calories, but it is a fallacy to believe that effect has to do with energy expended in chewing. Though chewing might feel like a somewhat strenuous activity, it burns about the same amount of energy as watching paint dry. It is the bodily energy devoted to the digestion of the green stalks that exhausts calories.
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It's not the apples inside him, it's the alcohol in cider.

2009-03-31T14:54:00.002+11:00

WARSAW - A Polish lawmaker who failed a drink-driving test said
he had eaten too many apples, the website of daily Gazeta Wyborcza said Monday.

Asked why a traffic police check Sunday showed he had 0.7 units of alcohol in his blood, Marek Latas denied having drunk alcohol that day.

"I am diabetic, I ate a few apples before driving.

"I have been involved in no accident, I underwent a routine roadside check. I was confident there was no chance I had alcohol in my blood," said Latas, a member of parliament for the conservative opposition Law and Justice Party. The prosecutor's office is investigating his case, the website said. In Poland, the legal limit for alcohol when driving is 0.2 units.

- Reuters

Cute story. Could it be true?

Assuming their alcohol limit is 0.05% (I don't understand 'units', that usually refers to drinks consumed.), the guy had a level of three and a half times that: 0.175%.

As a rule of thumb you blood alcohol level goes up by 0.01% per standard drink and down by 0.01% per hour. That blood level is equivalent to about 20 drinks over, say, three hours.

That's about 5 litres of 'liquor', requiring the juice of about three dozen apples.

Not only do you need to eat 36 apples, you need to retain them in your stomach for 3-6 days.

Not only do you need to retain them in your stomach for 3-6 days you need a yeast that will live in there. A stomach is about 100 times more acidic than the normal cider fermentation process. You need a super yeast and you need to be able to deal with a lot of released gas from the fermentation process. (burp).

And all that assumes that his liver is not metabolising the alcohol as it is produced.

Guilty as charged, I fear.

-

Ah, now I see!

2009-03-30T14:56:00.005+11:00

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A Sydney doctor has been studying human retinas since 1976 and says the carrot myth, that eating carrots is good for your eyes, started in World War II, is a "complete fabrication". Dr Beaumont is the director of the Macular Degeneration (MD) Foundation.

"When the English ... were ﬂying at night they used radar but the Germans didn't know that radar existed," Dr Beaumont said from his Sydney clinic. "The English certainly didn't want them to know so they put out a myth saying they were feeding their pilots carrots to improve their night vision and that's why they could ﬂy and see things at night.

Dr Beaumont recommends eating lutein rich foods for eye health. The lutein (found in spinach, corn and egg yolks) helps protect the eye from sight-damaging light that causes MD and blindness, Dr Beaumont explains.

On the ﬂipside, ironically, foods rich in beta carotene - like carrots - can damage the eye's protective shield, doubling your risk of contracting the disease.

So much for old wive's tales.

Related to that, there is at least one recorded case of a person dying from drinking excessive amounts of carrot juice.

While we need Vitamin A (beta carotene is a Vitamin A precursor), it is actually quite toxic.
...

Prostate Cancer and Red Wine

2009-03-26T11:47:00.006+11:00

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The Australian media was abuzz last week with a report that alcohol consumption increases the chances of prostate cancer. Two drinks a day will increase your risk by 20%. The risk increased with the number of drinks consumed in a day.

Before I pour my home brew down the drain, there are a few things I need answered.
(If you haven't read my previous post, now's a good time. I'll wait.)

Causality
Could alcohol consumption cause/increase the risk of prostate cancer? Possible.
Could prostate cancer risk cause drinking? Improbable.
Could a third factor be in play? Possible. Here are a few possible other factors:

People who drink large amounts of alcohol a day are often overweight. Is BMI a factor?
The consumption of chips, nuts and snack foods is probably proportional to drinks consumed.
Big drinkers often eat more meat.
Is consumption of other foods an issue - fibre, greens, fruit?
Do drinkers live longer, due to the heart benefits of alcohol, and get cancer due to longevity?

That will do. I'm sure we could come up with more. You can begin to see the difficulty of extracting two issues from a very complex life-matrix.

Crud Factor
Is a crud factor in play? Possibly. Sometimes a big survey like this finds statistical significance where no practical significance exists or will average out differences in reports.

Compare the following two extracts from studies into prostate cancer and alcohol consumption:

Our present study suggests that consumption of beer or liquor is not associated with prostate cancer. There may be, however, a reduced relative risk associated with increasing level of red wine consumption. Int. J. Cancer: 113, 133–140 (2005).

Wine or beer consumption was unassociated with prostate cancer; however, moderate liquor consumption was associated with a significant 61–67% increased risk of prostate cancer. International Journal of Epidemiology 2001;30:749-755

Looks as if beer is neutral, red wine gets a sort of a plus and spirits get a sort of a minus.

So does the report mean anything?

Too early to tell really but I will put a punt on the benefits of moderate alcohol consumption outweighing the possible down side.
...

Of sharks and ice-creams...

2009-03-26T11:03:00.007+11:00

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Really this post is about statistics but you wouldn't have come if I had said that.

The thing is that there are reports published everyday on every possible subject, many of them food and health linked. My next post, which prompted this pre-post, is on prostate cancer and red wine. I am doing this post separately as I think I will be referring to it time and time again.

Newspapers happily publish these 'shock-horror' health reports, edited, cherry-picked, sensationalised and often unverified.

Readers, knowing no better, accept them on face value.

To help me explain, let me now call on some sharks and ice-creams.

Sharks & Ice Creams - the pursuit of causality.
There has been shown to be a strong correlation between shark attacks and ice-cream consumption in Australia.

Does that mean eating ice-creams make you more prone to being eaten by a shark?

Does it mean that, having been attacked by a shark, you start craving dairy food?

Or could it possibly be that a third thing, maybe the season, is controlling both things?

Indeed it is the case that it is in summer that both shark attacks and ice-cream consumption increase.

Independently.

Causality is fundamental to interpreting any report. What caused what? Whenever you see a report in the papers linking two things, ask yourself the following three questions:

Is A really causing B, as claimed?
Could B actually be causing A?
Could something else, C, be causing both A and B?

The Crud Factor
The crud factor in statistics is an acknowledgement that everything is correlated.

If I was to find the data for tin production in Bolivia for the last ten years and also find the number of deaths in bicycle accidents in Belgium over the same period and plot them on an X-Y graph there would almost certainly be a correlation between the two.

A chance correlation.

It may be negative, it may be positive, it may be big or small, but it is most unlikely to be zero.

That is why all scientific research needs to be replicated; scientists test the same hypothesis (that tin production in Bolivia is impacting on bicycle fatalities in Belgium) using different data. If they can replicate the results then their confidence in the hypothesis increases.

It is not uncommon for replicate testing to fail to reproduce the original work.

Sadly, journal editors are not as keen to publish a negative result as they are to publish a positive and interesting one and such work often never gets beyond the waste bin. And, should they publish an article negating previous work, news media are far less likely to run it because it is not "news" and not shocking enough.

Summary
So, if there is a news item showcasing some horror relationship between a food and health or even some wonder cure, be ready to ask yourself if the implied causality makes sense and could it just be a chance correlation.

There you go. That didn't hurt, did it?
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More on Yoghurt

2009-03-25T13:56:00.005+11:00

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Laveviewer asked: I have two questions: Are homemade yogurt and ice-cream better for you than the commercial varieties? I'm thinking that if you make these products and use them within a week or two, you don't need to worry about preservatives.

Neither yoghurt nor icecream have preservative generally. If they do, it is usually from the flavourings. Sauces and fruit purees often have preservatives, notably sulphites and sorbic acid. The preservative are there to keep the flavourings from going off before being used.

Once a frozen product, like ice cream, is produced it has a considerable lifetime as freezing is a natural form of preservation.

Part of the benefit of yoghurt is its bacteria content, so in this type of product preservatives can be a problem in a different way. Yoghurt usually relies on it's acidity to inhibit stray bugs.

Both can be made at home, time and enthusiasm permitting. You also have a better input into possible flavours. I made a delicious grapefruit and honey sorbet last summer. You wont find that in the shops.

But are they better for you? Hard to say. Commercial icecream had a pile of stabilizers and emulsifiers, and often a bare minimum of fat, possibly not even dairy fat if they call it iced confection. But home made icecream can be made with eggs and cream, it is really a frozen custard - infinitely superior in flavour but moderation required!

Home made yoghurt is fine as long as you use proper care and sanitation for making it.
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The Silver Bullet School of Nutrition.

2009-03-25T13:49:00.002+11:00

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This is a previous post from "A Curate's Egg" but one which rightly belongs here and, in part, answers Kris loves Chocolate's question about which food are the healthiest for us.

I am not a fan of the ‘silver bullet’ school of nutrition.

By silver bullet, I mean the belief that some foods that are super foods.

Granted, some plants will kill you. That does not automatically mean that, in an effort to maintain even-handedness in the universe, there are some plants out there that are designed to save you.

But people seem to like wonder foods. Every year we hear about some berry, root or leaf from some exotic location that the native people know about and it keeps them happy, healthy and fucking like a hamsters, until they die of sexually induced exhaustion well into old age.

Oddly, these wonder foods seem to be most often sold by some multi-level marketing crowd.

Always, my first question is always the same: If this product is so good, why aren’t the pharmaceutical firms growing it, refining it, and mass producing it? Quinine was an example of where that did happen.

The problem with some of these wonder foods is that they are not supposed to cure a specific (and hence measurable) illness, such as malaria, but are generalists. They will stop cancer, aging, heart disease or some other intangible thing. Yes, death rates are measurable but you must keep an eye on causality. What’s that? The Hellarwi tribe never got heart disease AND the ate the wacko berry every day. Great! Perhaps the fact that they spent the day running around on foot and didn’t have an ounce of fat on them played a part too.

And the small matter of crocodile induced mortality.

Mind you, the crocodiles who eat the Hellarwi live to a ripe old age.

If you drink $40 worth of exotic berry juice a day and never get cancer, how do you prove it was the berry’s doing?

Perhaps you just weren’t going to get cancer anyway.
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Beef Jerky

2009-03-25T12:45:00.006+11:00

Photo: beefjerky.com

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Don said "I did a post about making jerky - dried meat. Someone asked if adding something sweet, like honey, might make the jerky less tough. The reasoning was because the sugar content makes a cake "softer". I don't know about the cake but do you think the sweetener would make the jerky less tough? (Not that I care, we don't like sweet jerky and go through this stuff as fast as I make it.)"

In theory honey or corn syrup would keep the jerky more supple but I would find the sweetness off-putting. Glycerine (Glycerol) may also work and is not so sweet.

Probably the best solution is to not dry it as much.

I occasionally make my own jerky. I use a variant of a recipe I found on line called Cliff's Fantastic Jerky. I vary it by using crushed garlic and chopped onion rather than the powders.

Far too nice to make too often.
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Wine & Champagne

2009-03-25T11:57:00.005+11:00

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Kris loves Chocolate wrote "When I drink (one glass, I am not talking getting tipsy here) wine, I get a horrible migraine. Once in awhile I can sip on white wine and be ok, but never red wine. I can drink Champagne though. Someone said I am allergic to the sulphates? No sulphates in Champagne?"

Most alcoholic drinks contain sulphites; it is added to stop fermentation, to kill off unwanted yeasts and generally as a sterilizer in the brewing process.

If the sulphites were the source of your migraines you would get it from wines other than red ones. And foods other than wine. Sulphites are probably the most ubiquitous preservative in our foods, often in levels far higher than found in wine. It is found in anything from dried fruit to manufactured meat. Some people do respond badly to sulphites but it is rare.

Possibly your response is to the histamines in red wine. These are absent (or low) in white wines. Taking an antihistamine tablet before consuming some red wine would tell you whether you are responding to histamines or not. Again, it is possible but rare.

Tannins are another possibility as red wine has more of them than white wine. The colour of red wine is extracted from the grape skins and tannin is also extracted in the process. If this was the case you would expect eating dark grapes would produce a headache. Even drinking tea may give a headache, though obviously different tannins are present in tea.

The short answer is that no one knows why some people get a headache from red wine.

Sorry.
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Yoghurt

2009-03-25T11:51:00.002+11:00

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Indi wanted me to "write about yoghurt". This is a broad sort of request! I will deal with it with a heap of observations and if there is anything people want to expand on we can deal with that later.

Yoghurt is a fermented milk product where the bacteria convert the lactose in the milk to lactic acid. The lactic acid gives the yoghurt the sour taste and ‘sets’ the milk by coagulating the proteins. The acidity also helps prevent other, possibly harmful, bacteria growing.

As the lactose in the milk is largely converted to lactic acid, yoghurt is usually well tolerated by people who are lactose intolerant and is easy to digest generally.

I am not a big fan of the fruit yoghurts, usually too sweet for me, but there is nothing wrong with them.

I like Jalna yoghurts but, for the one pictured above, take philosophical exception to the idea that (1) the product is fat free, it isn’t, (2) that fat free milk is in anyway natural, it isn’t. Not from the cows I know, anyway. Sadly, I don’t think they make full fat plain set yoghurt any more but their Swiss Custard Yoghurt is far too nice.

That hard white stuff you find on the top of ‘health’ bars might be called yoghurt but it isn’t. It is yoghurt flavoured fat, mostly saturated fat.

Probiotic yoghurt drinks probably do no harm (though they are twice as sweet as Coca Cola) but it is a open question as to whether they do any good. While the bacteria used will pass through the stomach into the intestines, they are not self sustaining and disappear from the system in a few days if not constantly replenished. I do not see their value and take the view that the flora that has thrived in the intestines over the eons are probably the best ones to have there.

Greek yoghurt has a higher fat level (10% cf normal yoghurt of 3%) and hence is more creamy.
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Lady Fi's Onions and a bit on gold, for good measure.

2009-03-19T21:15:00.006+11:00

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Lady Fi asks: Have you read my post about onions?
Why not tell us more about the tearful reactions they can trigger in lots of us?

Also - what's the deal about alchemy turning stuff into gold? How did it start? Why did people try? And is it really impossible?

Onions make you cry because, when you cut them, you release Propanethial S-oxide, a volaile compound that reacts with the moist surface of your eye to form sulphuric acid. Your eyes then water in response to this irritation.

Interestingly, onions do not contain propanethial S-oxide and it is thought that onions produce this tear inducing compound to protect the plant from herbivores. It is the product of a series of chemical reactions that occur once the onion has been damaged. Cells are broken open as the onion is cut and this releases the enzyme alliinase and water, which react with S-1-propenyl-L-cysteine sulfoxide forming a mixture of products including propanethial S-oxide.

Various suggestions are about to stop this process - cutting onions under water, chilling onions to reduce the volatility of the compound, heating the onion to kill the enzymes that create the compound, or what I sometimes do if the stove is free, cutting the onions under the exhaust fan on the stove.

And gold?

The alchemists have dreamed of turning lead into gold but, alas, had to fall back on other retirement schemes. Modern day nuclear physics has successfully transmuted lead into gold, but the expense far exceeds any gain. Ironically, it transpired that, under true nuclear transmutation, it is far easier to turn gold into lead than the reverse reaction, which was the one the alchemists had ardently pursued.

Reference:
http://www.chm.bris.ac.uk/motm/pso/psoc.htm
http://en.wikipedia.org/wiki/Nuclear_transmutation

The most dangerous food in the world!

2009-03-17T21:36:00.002+11:00

This is a repost from A Curate's Egg, but it is topical (re The Fat Duck post) and really belongs here .

In my previous incarnation as a food chemist I was often asked ''What food shouldn't we eat?"
I'm not sure what people expected me to say.

Butter, maybe.

In the incarnation prior to that one, I worked at the Coroner's Court doing post-mortem drug analyses. No one ever asked me what drugs they shouldn't take.

However, there I am, Food Chemist, at a dinner party or a BBQ and after the obligatory "What do you do for a living?" question I get the "Oh, really? What food shouldn't we eat?" question. Always tricky if you don't know what is on the menu. But few people are ready for my reply.

Alfalfa sprouts.

Yes, those clean, green, biodynamically pumped shoots are one of the most treacherous foods on the menu.

"Surely not! You're joking, right?"

Wrong.

Think about it. Seeds of any sort are open to the environment. They will have bacteria on them. So what do you do with them? You soak them in water and leave them somewhere warm for three days. Water, warmth, and the seed, a good souce of protein. Bacteria heaven.

"But sprouts have been eaten for centuries." they protest.

"Cooked" I respond. Eating sprouts raw is a recent 'healthy' practice.

Cooking sprouts will kill any bacteria.

That doesn't mean that raw sprouts are bad, just that they are high risk. There is no safety net.
You can reduce the risks by using boiled or chlorinated water and changing the water frequently.

"Now, would you like my thoughts on curry powder? Or margarine?"

"Ah ... that's very kind of you but I can see an actuary over there that I have been dying to talk to ... "

The Fat Duck & Quantum Chemistry

2009-03-16T20:21:00.007+11:00

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Chairman Bill asked: "Would you care to comment on The Fat Duck interpretation of quantum chemistry."

He expanded later, with: The Fat Duck is a 3 star Michelin restaurant in the UK run by Heston Blumenthal, who is renowned for using the principles of chemistry in his menu design. Unfortunately he had to close down for a couple of weeks due to an outbreak of vomiting and diarrhoea, although the health inspectors gave his place the all clear.

I have met up with a Spanish equivalent, el Bulli. My son, Richard, gave me a megabook on a day in the life of el Bulli for Christmas.

I find it a cute idea but I can't afford to go to the restaurant and I can't afford the equipment needed to do a lot of it at home. They do things like use liquid nitrogen to freeze things. Fascinating but out of the reach of the home cook. There must be a few things I can do so that I can impress Richard; I have a dehydrator for example. (Watch this space.)

What really caught my attention was the comment by Chairman Bill that the UK restaurant had been closed due to food poisoning. It may well have been coincidental and nothing to do with the restaurant (that is often the case) but it does play to one of my food safety themes: be very wary of food prepared in non-traditional ways.

I will write more another day on the subject but most food is safe because we prepare it the way countless previous generations have prepared it. And survived. The problem is most people don't understand why this is the case and, in ignorance, try shortcuts.

With quite dire results, sometimes.
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Grey Water

2009-03-16T20:02:00.003+11:00

Anonymous said:

Not sure if this is up your alley, Lee, but I've heard you shouldn't put grey water (say water from the shower that might have a bit of soap and dead skin in it) onto plants that you intend to harvest for food later, like herbs or pumpkins. If this is your sort of area, what's the deal?

The issue is that the water has more than soap and skin. It will have faecal matter, no matter how well you have wiped your bum. Blunt but true. The same applies to laundry water that has been used to was undies etc.

Related to that is the issue that this bacteria will multiply if people store the water for any length of time. The resultant soup is smelly, slimey and a hazard to children.

The counter story, and there is always a counter story, is that the plants in the vegetable garden are routinely exposed to salmonella, ecoli and other such nasties from the wind, birds and insects. If normal hygienic practices are followed, there shouldn't be a problem.

Interspersed with all this bacterial culture is the litigious culture that abounds at present; no politician is going to say 'use your grey water on your vegetables' and then face the consequences of a potential food poisoning. Far safer, politically, to say don't use it.

Me? I used grey water on my raspberries; they are not in fruit until October so no problem and they survived the summer better than they ever have. A bit sunburnt but you can't help that with watering. I also used it on some rhubarb, knowing it would be comprehensively cooked and never eaten raw. I used grey water extensively around the main garden and on all the fruit trees.

Ideally, if you need to use grey water on vegetables, you should contour your garden beds so that you can water them by running the water down a ditch between rows so that it gets directly into the soil without touching the vegetables themselves.
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Chemists and Food

2009-03-15T20:43:00.004+11:00

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Chairman Bill asks: "My partner is a biochemist and maintains that if you're a half decent chemist, then you understand food and should be a natural cook (she is the best cook I've ever come across)." and "If chemistry was a compulsory subject at school, would people be more likely to tackle cooking?"

Well, my interests include chemistry and art. I take the view that cooking is where the two overlap. To my mind, art is the more important of the two - everything hinges on presentation.

To that end I only use white plates.
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Food Additives

2009-03-15T20:07:00.004+11:00

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Courtney asked for my “thoughts on food additives in our diet. Specifically, what is your scientific and always logical take on artificial colors/dyes and preservatives in the food and their impact on behavior?”

The answer varies with the additive unfortunately.

Additives fall into a variety of categories but the first major split is into colours and others. Courtney specifically refers to colours, antioxidants and artificial sweeteners.

Colours
Colours are really for cosmetic purposes only and serve no useful purpose to the consumer. They can make pallid and insipid looking foods look more attractive (eg: adding yellow to pasta, cakes or ice-cream makes them look a richer colour, as if they have eggs in them.).

There is no doubt that colours are not necessary. They are an aesthetic additive.

Antioxidants (BHA, BHT, TBHQ)
These additives are generally added to oils and oil containing products to delay the onset of rancidity and extend shelf life; to this end they serve a useful purpose. As well as flavour deterioration, the by-products of rancidity, peroxides and acids, are considered to be harmful. This is where antioxidants have a problem: they are an additive but, unlike colours, they do serve a functional purpose. And this is where the regulators need to walk a fine line: the health risks of the additive vs the health risks of not using the additive.

Artificial Sweeteners
These are more insidious additives, in my mind. There is no denying that obesity is a growing problem (!) but is replacing sugar with something sweet but without calories the answer? It is not training people to enjoy unsweetened food but rather maintaining a need for a certain level of sweetness. Also people do false bargains with the devil when they say “I had a diet cola so I can have a chocolate bar”.

Preservatives
This is a fairly broad group of additives. Sulphur Dioxide is used very widely for different reasons. With the likes of sausages, they will not last a day raw without preservative (because you are seeding the minced raw meat with bacteria filled other components – flours, spices etc.). Dried fruit, such as apricots, go dark brown without preservative but will survive quite well without it IF they are properly dried. If they are kept still moist, (could they be being sold by weight?) yeasts can grow in them. Many soft drinks contain the preservative Benzoic Acid to prevent the growth of bacteria during storage. Again there is the issue of the health risks of using the additive vs the health risks of not using the additive.

At one level, it seems logical that manufacturers will not use additives unless they feel that they are needed in their food. Why incur an unnecessary cost? But reality is that the cost of the additive is not great and the ability of the manufacturers to control the amounts added is variable. Ultimately, as an insurance, they often use too muych rather than too little.

That was the easy bit.

“Are these additives harmful?” is a harder question. At some point everything is harmful. One grain of sand will bounce off you shoulder, a truck full dumped on you will smother you. Do additives impact on children’s behaviour? Quite possibly. There is the issue of causality though. This is something that I will probably come back to time and time again in this blog. Do colours make your child hyperactive? Or is it the sugars that are often present with the colours? Or something else altogether?

Ultimately it is something that must be decided on a case by case basis. If they affect your child, all the assurances of the ‘experts’ amount to nothing; they affect your child.
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Post a Question

2009-03-15T16:23:00.002+11:00

If you have some topic you would like me to post on, post it as a comment to this post and I will see what I can do.

Once I have posted on the topic, I will remove the comment so the comments will represent a 'to do' list for this blog.