Lecithin is an emulsifier. It's purpose is to assure that the different fats that constitute chocolate stay blended together. Cocoa butter, unlike hydrogenated fats, is not uniform and a blend of fats of different hardness. Lecithin makes sure they stay blended and that the fat crystals remain stable once the tempering is achieved. Lecithin essentially helps protect chocolate during prolong storage and temperature variations during storage. It helps delay (prevent) chocolate blooming (powdery graying which is fat crystals that have melted, leached and disorganized).
On average lecithin is added at below 2% (usually around 0.5 to 1%).
In Canada, emulsifiers cannot exceed 1.5% by weight.
other emulsifying ingredients that have similar effectiveness to lecithin and are accepted in Canada are:
mono-glycerides and mono- and diglycerides,
hydroxylated lecithin,
ammonium salts of phosphorylated glycerides,
polyglycerol esters of interesterified castor oil fatty acids,
and
sorbitan monostearate.
Lecithin is commercially extracted from soy (hence commercially cheap) but it is also found in eggs. It is the emulsifying work horse in mayonnaise making (in conjunction with some emulsifying agents found of mustard seeds).
Probably every commercial chocolate made in the world contains some sort of emulsifier. One just needs to read labels and choose what to avoid. I can say that the least <processed> emulsifier ingredient is in fact lecithin. It is a simple extract. All others mentioned above are a by-product of a chemical reaction in some way.
Luc H
Foodpump... should I wait to give the answer to my quiz?