Lipids

Abstract

Lipids are a broad group of naturally-occurring molecules that are soluble in organic solvents but insoluble or only sparingly soluble in water. Triacylglycerols account for 95% of total lipids in foods. Lipids are major energy source for human body and protect human body from mechanical damage and heat loss. Lipids are also the carriers of fat-soluble vitamins and the precursors of many bioactive molecules such as prostaglandin, sex hormone, and epinephrine. This chapter deals with the nomenclature, classification, and fatty acid distribution theories of lipids and their functional properties, including polymorphism, plasticity, and emulsification. Lipids undergo multiple chemical reactions during processing and storage, such as hydrolysis, oxidation, and thermal decomposition. The effects of these reactions, especially oxidation, on food flavor and safety are elucidated in detail. Lipid processing techniques, including refinement, hydrogenation and interesterification, are also concerned in this chapter. © 2012 Nova Science Publishers, Inc. All rights reserved.