Kitchen/Food Science

[hans.schallenbe]

Originally Posted by scott123

Acid 'breaks down' fat? I wasn't aware of this. In what way does it 'break' down?

Lecithin, btw, is not a fat, it is a phospholipid.

Lecithin (Nervous, Circulatory) is a fatlike substance called a phospholipid. It is produced daily by the liver if the diet is adequate. It is needed by every cell in the body and is a key building block of cell membranes; without it, they would harden. Lecithin protects cells from oxidation and largely comprises the protective sheaths surrounding the brain. It is composed mostly of B vitamins, phosphoric acid, choline, linoleic acid and inositol. Although it is a fatty substance, it is also a fat emulsifier. Hence, it supports the circulatory system. Its choline is useful for making acetylcholine. Lecithin is derived from soybeans too.

source from yahoo, type lecithin

i hope i am not too agressive to all out there,for me lecithin is a fat like substance also present in the egg yolk. together with the proteins they form an emulsifier, in making a hollandaise or a mayonnaise.

the next open question is still, the acidity interacting with the lecithin and the protein.

i give an other example of acidity interacting with the protein. kilawing, a native dish to the philippines.

grouper fillet thinly slices and marinated in ligth vinager and spices. the fish gets cooked, as the vinegar denatures the protein.

so if i add vinegar to an egg yolk from the start of a mayonnaise preparation will the reaction be different?

well that is my question.

please i can be wrong too. now bad feelings but lets clarify. chefs should all speak the same language.

hans

type yahoo

Phospholipids are made up of a hydrophilic head and a hydrophobic tail. The head group has a 'special' region that changes between various phospholipids. This head group will differ between cell membranes [types of cells] or different concentrations of specific 'head groups'. The fatty acid tails call also differ, but there is always one saturated and one unsaturated 'leg' of the tail.
Phospholipids are 2 fatty acids one saturated and one unsaturated .

[scott123]

Originally Posted by hans.schallenbe

i hope i am not too agressive to all out there,for me lecithin is a fat like substance also present in the egg yolk. together with the proteins they form an emulsifier, in making a hollandaise or a mayonnaise.

No, lecithin is an emulsifier. Period. The protein has no impact on lecithin's ability to emulsify.

the next open question is still, the acidity interacting with the lecithin and the protein.

i give an other example of acidity interacting with the protein. kilawing, a native dish to the philippines.

grouper fillet thinly slices and marinated in ligth vinager and spices. the fish gets cooked, as the vinegar denatures the protein.

so if i add vinegar to an egg yolk from the start of a mayonnaise preparation will the reaction be different?

well that is my question.

Yes, acid denatures protein. That is very true. The hollandaise example you present is a protein/acid (as well as heat) denaturation. As is your saurbraten example. The effect of acid on protein is not the 'open' question here. The open question is acid's affect on the 'fatlike' lecithin.

From ASSURING SAFETY OF EGG YOLK-BASED SAUCES AND SALAD DRESSINGS
by O. Peter Snyder, Jr., Ph.D.

The emulsifying capability of egg yolk is mainly related to its content of lecithin (about 1.22% of the yolk) (Stadleman 1986). Lecithin is a phospholipid and is not affected by the acid/heat pasteurization process and remains an effective emulsifying agent in the pasteurized egg yolk/acid mixture.

Will the acid's denaturation of the protein in the egg yolk affect the final output? To a minimal extent, perhaps. As I said earlier, the protein isn't the emulsifier here. The lecithin is. And that is acid independent.

[newbiecook]

Vinegar stops bleeding cause of the pH difference between that and the Blood...Blood can only with stand a 0.2 pH difference either way, so by putting anything acidinc or Basic into a bleeding wound should cause the blood to coagulate and stop bleeding.

[Nicholas]

Thanks for the further suggestions.

Newbiecook, you've shed some light on that, I'll know where to start researching. Thanks!