Kitchen/Food Science

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Nick,

Take a look at this site by Chef Simon. It's pretty cool.

 

Kitchen science: A compendium of essential information for every cook
by Howard Hillman
This is a great book. Do a google search for Kitchen Science Amazon and you will pop up quite a few interesting books with that in the title.

 

Harold McGee's On Food and Cooking is the food science bible of the CIA (at least that's my understanding). But you might want to wait just a bit before buying it because he's coming out with a substantially revised edition any moment now.
Robert L.Wolke's What Einstein Told His Cook and Russ Parson's How To Read a French Fry are both a lot of fun and more reader-friendly if science was not your best subject in school but you still really like it.

 

Cookwise: The Hows and Whys of Successful Cooking by Shirley O. Corriher

 

cooking techniques, that is the term you will find in the english version in the philip pauli book [classical cooking the modern way] page 222 to 227.

in this pages, which are truly brief, it explains the effects of water, carbohydrates, fat and protein in cooking.

having read this now, you have to focus on the product knowledge, how each product has a chemical composition, like the egg yolk contains lecithin [fat], that is the reason why, when making a fresh mayonnaise, you add the acid last, as acid breaks down fat.

hans

 

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.

 

Good for you for being inquisitive. Pick up any book by Hervé This (French scientist, but his books have been translated in many languages).

 

That's the one I always turn to. In a pinch you can always ask Kuan :chef:

 

I own both Harold McGee's "On Food And Cooking" and "Cookwise: The Hows and Whys of Successful Cooking" by Shirley O. Corriher. I enjoy them both. The first reads like a text book and would only be enjoyable for anyone who is truly intrested in learning more about the how's and why's of cooking. The second on the other hand is broken down into more practical yet still informative information along with being paired with recipes to show examples of the scientific principles being explained. I do reccomend both and am glad I begged my wife to get them for me for christmas.

 

lipid, and assists in building of cell membranes, nerves, bone marrow and blood cells. it has fat and water soluble properties, it functions as an emulsifier in hollandaise and mayonnaise, chocolates etc. together with the proteins.

how acid breaks down fat, make a mayonnaise, one add the vinagar together with the egg yolk, the second one add it last and you will see the difference.

hans

 

Hans, the difference in results you describe are based upon the water constituent in the vinegar, not it's Ph level. If you perform the same experiment with water (adding it to the yolk or at the end), you'd get the same results. It has to do with the amount of lecithin in the yolk and it's emulsifying capabilities. I don't see how acidity has anything to do with emulsification.

 

well that is what we learned.

however try it out, same you have with the hollandaise, if your reduction is too strong [acid], your hollandaise will never be that firm and will not hold as long.

an other example along the same line with fat and acidity is when you prepare egg whites [foaming] if you are not sure if there are fat stains in your container you quickly clean the container with lemon, as fat inhibts egg white from foaming.

an other point with acidity, when you marinate a sauerbraten or game stew with vinegar and or a rather acid red wine, acidity has an direct reaction with the collagen in the connective tissues, as they expand and soften [weaken] and become gelatinous and tender.

well im am not sure unless there is an other chemical explanation, the way acidity interact with proteins, lecitin and others.

hans

 

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 .

 

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

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.

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.

 

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.