Monday, August 29, 2011

Not ducking the question.


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.

Sunday, August 21, 2011

Stamps. And the perils of licking them.

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.


Thursday, August 4, 2011

The Hormonal Cow


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.