*2.5.7 Millet*

*Innovation in the Food Sector Through the Valorization of Food and Agro-Food By-Products*

*Zea mays* L., alternatively referred to as corn is a native of the Western Hemisphere and its production in the USA exceeds that of others countries [72]. The kernel which is the reproductive seed of the plant has four main parts, and these are the germ, the endosperm, the pericarp and the tip cap. It is an inexpensive source of starch and it is a major source of energy for animal feed [65, 70]. Among the hundreds of different varieties of wheat grains, only four varieties listed below

1.Dent maize (identified by the dent in the crown of the kernel);

4.Popcorn (flint-type maize which expands when heated).

Barley is a resilient plant that can tolerate a wide range of conditions, which might have been cultivated since 15,000 BC [72]. The head or spike of barley is made up of spikelets that are attached to the rachis in an alternating pattern. The barley kernel's outer layers consist of the husk, the pericarp (to which the husk is tightly joined in most species), the testa or seed coat and the aleurone which completely covering the grain. Barley (*Hordeum vulgare*) is mainly cultivated for malting and brewing in the manufacture of beer and for distilling into whisky manufacture [65, 70]. The spent grains from the brew are used as animal feed, especially for pigs. However, a small amount of barley is used for food. Pearled barley is used in cooking soups and stews in the UK and in the far Middle East. Barley flour is also used in

bread production and can be cooked as porridge in some countries [67].

Among the several different species of oats, spring or white oat (*Avena sativa* L*.*) is the most important cultivated form. *Avena byzantine* is a red-oat type or alternatively known as a winter oat is cultivated in warmer climates [65, 70]. A spikelet of oat consists of oat kernels. A hall which is made up of two layers called the lemma and palea, enclosed each kernel, the hall is only loosely attached to the groat. However, the groat is made up of 65–85% of the oat kernel and it is enveloped by bran layers (pericarp, seed coat and aleurone cells) [65]. It grows well on poor soil and in cool, moist climates and has mainly been grown for animal feed. Its cultivation for human consumption is at minimal level, products made from oats are oatmeal for porridge and oatcakes, rolled oats for porridge and oat flour for baby foods and for ready-to-eat (RTE) breakfast cereals [67]. Non-food uses of oats include their utilization in the

Rye is generally a hardy plant and it is wildly cultivated in cool temperature zones, where other cereals can merely survive. Rye can also be grown in semi-arid areas and at high altitudes. It is cultivated as a winter crop, which is sown in early autumn and harvested in early summer [65]. The plant varies in height from 30 cm

*2.5.3 Maize*

*2.5.4 Barley*

*2.5.5 Oats*

are of commercial importance:

2.Flint maize (hard, round kernels);

production of cosmetics and adhesives [70].

3.Sweet corn (a dent-type maize);

**202**

*2.5.6 Rye*

Millet is an annually cultivated cereal which possesses different species of small grains [64, 70]. Among the various species of millet, pearl millet is the only one that is mostly of economic concern. Other known species of millet include, finger (or ragi), proso and foxtail, but the minor millets account for less than 1% of the grains produced for human consumption, they are less important in terms of world food production [65, 70]. Cultivation of millet is of utmost importance in certain locations in Africa and Asia where major cereals cannot be solely depended on to provide sustainable yields [73]. The species type influence climatic and soil requirements, length of growing period, grain consistency, size and taste of millet [64].
