Oats-Structure

STRUCTURE OF OATS

Cereal grains are distinguished from other grasses by having simple,dry and indehiscent fruits. The pericarp , or fruit coat , is attached to the remainder of the fruit around the entire periphery.

The gross physical structure of the oat groat is similar to that of the kernels of wheat and barley. It is however , covered with numerous trichomes or hair like protuberance.The three major divisions in to which the groats can be divided are the bran , endosperm and germ. Starting from the outside of the groat , the bran layer consist of the epidermis , seed coat , hyaline layer , and aleuron cells , in that order. The germ is made up of embryonic cells and cell wall tissues , while the endosperm is composed mainly of starch cells

The oats germ , when viewed in a longitudinal section of the kernel, extends roughly one-third of the way up the ventral side of the groat. It is larger and narrower than the germ of wheat . Bounding the germ is a layer of columnar cells which are strongly colored by protein strains.

Compared to other cereals , oat groats are characterized by low carbohydrate content , and higher protein and fat content. Using selective stains followed by microscopic observation of sections, lignin has been identified in the epidermis , aleurone cell walls , endosperm cell walls , and germ cell walls. Protein would be expected to be more or less ubiquitous , but positive reactions for it were found in the aleurone cells , germ cells , and endosperm cell walls. Starch appeared to be confined to the endosperm , where it occurred in well-defined aggregates . The germ and the aleurone cells were determined to be the major lipid depots . There were traces of pectin in the horny endosperm and epidermis.