Anatomy - Chemical Composition, a Review

Cereals, in contrast to forage grasses, form a relatively large fruit, termed a caryopsis, in which the fruit shell is strongly bound to the seed shell. The kernel size, which is expressed as grams per 1000 kernels (Table 15.5), is not only dependent on the kind of cereal but on the cultivar and crop production techniques, hence it varies widely. 

In oats, barley, and rice the front and back husks are fused together with the fruit. In contrast, threshing separates wheat and rye kernels from the husks as bare seed. 

The major constituents of seven kinds of cereal are fairly uniform (Table 15.6). Noteworthy variations are the higher hpid content in oats and a lower fiber content in millet and rice. The available carbohydrates consist mainly of starch. Oats are especially rich in nonstarch polysaccharides (cf 15.2.4.2). These cereals also differ in their vitamin B content (Table 15.6). 

Fruit and seed coats enclose the nutrient tissue (endosperm) and germ in the kernel (Fig. 15.2). Botanically the endosperm consists of the starchy endosperm (70-80% of the kernel Table 15.7) and the aleurone layer, which, with exception of barley, is a single cell layer. 

The aleurone layer is rich in protein and also contains fat, enz)mies and vitamins (Table 15.8 and 15.9). The proteins, of which half are water-soluble, appear as granules in the aleurone cells. They have no influence on the baking properties 

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