Thursday, February 16, 2012

Coffee, Tea...

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Peter Bryenton asked "I was wondering how much caffeine there is on average in an ordinary cup of instant coffee?"

Not an easy question as the consumer is in control of how strong they make the coffee and how big a cup they use.  Generally instant coffee powder is about 2-3% caffeine and instant coffee is about 330mg/L (about 75mg per cup).  But I know my first cup of coffee in the morning is considerably stronger than my last of the day.

Tea is generally only about 80% of the caffeine levels of coffee but, again, this varies with type, cup size and steeping time.  Herbal teas generally have none but be careful of flavoured green teas, they have similar levels to black tea.

Colas are about 100mg/L; a third that of tea and coffee.

The much vaunted 'Energy Drinks' are only permitted a maximum of 320 mg/L in Australia and so are on a par with tea and coffee.  Not that they would want an image of a little old lady sipping her cuppa to be equated to the macho image of the heroic energy drink urban warrior-rapper-sportsman.
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Sunday, February 12, 2012

Anticancer Spears

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Kevin Bell asked: "Any info on the email going around that Asparagus is good for curing cancer? This also seems incredulous, the pharma industry are not stupid and would be onto it quickly enough if there was any credibility in it."

Well, yes, I think you nailed it yourself, Kevin.

If there was any truth in it, it wouldn't be being sold at $4 a bunch at Woolworths.

As I understand it, cancers are initiated when your body loses the plot with regard to cell regeneration and starts an uncontrolled multiplication. 

I can see no reason why a food, any food, would stop this.  I would be more inclined to believe that eating excessive amounts of asparagus would cause problems rather than the reverse.

Too much of anything is bad.

But moderate amounts of asparagus with a good home-made hollandaise sauce is not bad for you and, indeed, can improve your emotional well-being no end.

By the way, I haven't seen the email that you mention, but I am sure that the miracle chemical in asparagus will be Rutin.  Love the name.  It is a naturally occurring flavonoid found in a number of foods.  As well as in asparagus, it is also in buckwheat, citrus peel, mulberries and cranberries.  In canned asparagus it appears as white or grey flecks in the spears.  Something about the canning process triggers crystallisation.  Quite beautiful crystals under the microscope.
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A load of old rhubarb

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I made mention on my home blog that my rhubarb was green and that I was adding elderberries to it to make it look more 'normal'.  I have seen recipes that added strawberries to give colour.  A few people asked if green rhubarb was safe.

Yes, it is.

The green stemmed rhubarb is a fast growing, thick stemmed hybrid.  Quite safe.

The poisonous element in rhubarb is a chemical called Oxalic Acid and it is found at high levels (0.5%) in the leaves, regardless of the stem colour.

Oxalic Acid is also found in many other plants but not at the levels found in rhubarb leaves.  Excessive Oxalic Acid consumption results in kidney stones (Calcium Oxalate).  A lethal dose of rhubarb leaves is about 5kg.
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Saturday, January 14, 2012

Potomatatoes & Acidity

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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Wednesday, December 14, 2011

Cancer and spices.

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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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Sunday, October 30, 2011

Take it with a pinch, no, a bag of salt!

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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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Monday, August 29, 2011

Not ducking the question.

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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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