The lipid fraction is a minor component of the wheat grain, constituting about 3%-4% of whole grain weight, and even less (1%-2.5% by weight) in the endosperm.
A wheat kernel weigh 30-42 mg and contains 0.92-1.24 ug of lipid. The germ and the aleurone cells are rich in triglycerides which are present as spherosomes, while phospholipids and glycolipids predominate in the endosperm.
The lipids are a useful source on n-6 and n-3 types of polyunsaturated fatty acids, a wheat germ is exceptionally rich in vitamin E tocopherols.
Free fatty acids, simple glycerides, galactosyglycerides, phosphoglycerides, sterol lipids, sphingolipids, diol lipids, tocopherol, carotenoids, wax esters and hydrocarbons are among the lipids found in wheat kernels.
The principle glyceride in wheat is triglyceride, with minor amounts of diglyceride and monoglyceride.
Flour lipids play an important role in the dough-mixing and baking processes. They interact and form complexes with gluten protein and contribute to the stabilization of gas-cell structure, thus having significant effects on loaf and on final texture.
Some oxidation of lipids by wheat lipoxygenase occurs in dough, but more important oxidations resulting in dough improvement require soya lipoxygenase, and both contribute to the oxygen requirement of the dough.
Lipid in Wheat
