INGREDIENTS ORCHESTRA

The transformation of basic ingredients into the unique structure of a cake is, depending on how you look at at, a piece of alchemy or a complex physico-chemical process.

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CHEMIST IN THE KITCHEN

Chemicals have always been welcome in the kitchen: sodium bicarbonate, pectin, yeast, acetic acid etc.

Here is a complex chemical process described step by step:

In the first stage glyceryl esters of fatty acids are warmed to increase their plasticity, then creamed with sucrose, during which stage air particles become entrapped in the mix. Phosphatidylethanolamine is now beaten into the matrix which is now a foam emulsion with droplets of glyceryl esters of fatty acids and air dispersed within. Amylopectin and amylose, the protein gluten, and sodium bicarbonate are added. Crosslinking occurs between disulphide bonds in the gluten, creating a rubbery texture, with air trapped in the mix. When the mix is heated the air and water particles expand making the foam rise. Ovalbumin coagulates and stiffens the lining of the cells. Amylopectin and amylose undergo gelatinisation which further stiffens the mix. The foam expands and becomes a solid gel with a light porous texture.

This might sound like the production process for something like expanded polystyrene but it is of course baking a cake, and it is indeed as precise a physical and chemical process as the description implies. The process is rarely regarded in such a technical light simply because of its homeliness. What are these ingredients doing? Each has a distinct physicochemical function: egg yolk contains an excellent EMULSIFIER, lecithin, vinegar is an ACIDIFIER, flour contains gluten which is (as in flour paste) a BINDING AGENT, lemon juice is an ANTIOXIDANT, TENDERISER, and ACIDIFIER, sugar is a PRESERVATIVE. These categories of course sound like additives. And that is really what they are. All these natural homely ingredients contain specific chemicals and they are used to achieve a definite effect.

Chemical additives grew from our knowledge of the properties of these familiar kitchen ingredients. Everyone knows that cake-making is a very precise art, a false step can result in a soggy mass rather than a light, fluffy cake. And this is how additives are used; to achieve precise effects. The notion that they are superfluous and that good food could be produced simply by omitting them is as wrong-headed as hoping to produce a good cake by throwing the ingredients together and hoping for the best.