| Lecithin |
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| Written by Rick Cavanaugh | |
| Thursday, 09 August 2007 | |
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Lecithin is commercially extracted from soybean and may be classified as a natural emulsifier and lubricant. Lecithin is also naturally occurring in eggs. Lecithin is mostly a mixture of glycolipids, triglycerides, and phospholipids (e.g. phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol). Lecithin's are a group of emulsifiers with different properties, specifically HLB ratios. HLB measures the hydrophilic lipophilic balance. Lecithins are available with HLB ratios ranging from 4.0 to around 12. In cake batters, lecithin promotes fat distribution and improves batter flow. Lecithin is available in liquid form, as well as a de-oiled powders. Lecithin ensures even mixing, wetting of the ingredients, pan flow, egg yolk sparing agent and improves crumb texture. Soy lecithin has also been functionally improved by purification through fractionation, wherein the phosphatidyl choline (PC) content is concentrated. Such fractions have shown excellent functionality in chemically leavened baked goods. An enzyme-modified lecithin has excellent dough-conditioning properties in yeast raised baked products. There is also synergy between lecithin and some chemical emulsifiers. For example, blends of lecithin with monoglyceride improve dough feel, as well as increase shelf life. Enzymatic hydrolysis of lecithins HLB values between 5 and 10; therefore, its application possibilities can include systems where medium or high polarity is essential. Applications are bread and pastry products, light margarine and water based sauces in food or "leather fat liquoring" in chemical industry. The high water content in all of these systems calls for a rather high polar emulsifier. Lecithin with a HLB ratio of 4 to 5 are good water in oil emulsifier. Lecithin with a HLB ratio of 5 to 8 are good wetting agents. Lecithins with HLB Ratios of 9 to 12 are good oil in water emulsifiers Lecithin helps promote solidity in margarine. Lecithin enhances the structure and firmness of whipped toppings and improves the dispersibility in coffee whiteners. Lecithin can give consistent texture in creamy dressings. Lecithin is also used in confections such as chocolate and coatings to promote blending, reduce sticking and tackiness. Lecithin can also be used as a pan release agent. |
