Comparative Study on Proximate Composition of Local Cereals (Maize, Wheat and Sorghum)
Objective of the Study
Therefore, the aim of this study was to comparatively study the proximate compositions of local cereal (maize, sorghum, and wheat).
Cereals can be deﬁned as a grain or edible seed of the grass family, Gramineae (Bender and Bender, 1999). Cereals are grown for their highly nutritious edible seeds, which are often referred to as grains. Some cereals have been staple foods both directly for human consumption and indirectly via livestock feed since the beginning of civilization (BNF, 2004). Cereals are the most important sources of food (FAO, 2002), and cereal based foods are a major source of energy, protein, B vitamins and minerals for the world population. Generally, cereals are cheap to produce, are easily stored and transported, and do not deteriorate readily if kept dry.
General Structure of Grains
Grains develop from ﬂowers or ﬂorets and, although the structures of the various cereal grains are different, there are some typical features. The embryo (or germ) is a thin-walled structure, containing the new plant. It is separated by the scutellum (which is involved in mobilization of food reserves of the grain during germination) from the main part of the grain, the endosperm. The endosperm consists of thin-walled cells, packed with starch grains. If the cereal grain germinates, the seedling uses the nutrients provided by the endosperm until the development of green leaves that allow photosynthesis to begin (FAO 2001; Kent and Evers 2004). The endosperm is surrounded by the aleurone, consisting of one or three cell layers (wheat, rye, oats, maize and sorghum have one; rice and barley three). The outer layers of the grain are the pericarp (derived from the ovary of the ﬂower) which surround the seed coat (the testa). The outer thick-walled structures form the bran.
Wheat is a major cereal crop in many parts of the world. It belongs to the Triticum family, of which there are many thousands of species (Kent and Evers, 2004), with T. aestivum subspecies Vulgare and the hard wheat T. durum being the most important commercially (Macrae et al., 2003). Wheat is grown as both a winter and a spring cereal and, owing to the number of species and varieties and their adaptability, it is grown in many countries around the world. The great wheat-producing countries of the world include the USA, China and Russia; extensive wheat growing occurs in India, Pakistan, the European Union (EU), Canada, Argentina and Australia. It is estimated that 556.4 million tonnes of wheat will have been produced in 2003, accounting for 30% of the world’s cereal production (FAO, 2003). An ear or spike of grain is made up of spikelets. The wheat grain is enclosed between the lemma and the palea of each spikelet. The grain may be elliptical, oval or ovate in shape and have short or long brush hairs. Most cultivated varieties of wheat have fusiform spikes, may be awned (bearded) or awnless, and are easily threshed.
Wheat is generally not classed by variety. Instead classes are used, based on the time of year the wheat is grown and the milling and baking quality of the ﬂour produced. Within each class there is a group of different varieties of wheat with similar characteristics. Most of the wheat produced is used for human consumption and because of its unique properties, a large range of ingredients and foods are produced, including wheat germ, spelt (a coarse type of wheat), couscous, cracked wheat or bulgur and wheat starch.
The crop, which has been cultivated for over 10,000 years probably, originates in the Fertile Crescent, along with other staple crops. However, ancestral wheat may have looked very different from what we presently have today, with much smaller kernels. Early domesticators of wheat obviously wanted to select for plants with particularly large kernels, since more nutrient could be eked out from each stalk.
Wheat has been cultivated in Nigeria for centuries (Macrae et al., 2003). Ample evidence exists to show that wheat has been cultivated in Nigeria as early as 200BC, although the currently cultivated varieties are relatively recent introduction. However, Nigeria’s domestic wheat production has remained at a very low level in spite of the ever – rising demand for the crop. The constraints to the cultivation of wheat in most wheat growing areas in Nigeria include climatic requirements, appropriate agronomic practices and preference for the cultivation of vegetables (FAO, 2003).
MATERIALS AND METHODS
Wheat, Maize, and Sorghum were obtained from the local market in Owo, Ondo State. The materials were taken to the laboratory for analysis in the department of Food Science and Technology, Rufus Giwa Polytechnic Owo, Ondo State.
Preparation of samples for analysis
The samples (Wheat, Maize and Sorghum) were sorted and cleanse to remove all foreign materials such as dirt and stones, before they were taken to the laboratory for proximate analyses.
RESULTS AND DISCUSSIONS
Table 1: Proximate Compositions of Maize, Wheat and Sorghum
CONCLUSION AND RECOMMENDATION
Cereals have been a mainstay of the diets of people worldwide, since records began. Even with the diversity of foods now available, cereals remain a fundamental part of the dietary pattern, providing energy and ﬁbre, and a range of nutrients, such as carbohydrate, protein, B vitamins, vitamin E, iron, magnesium and zinc. This study proved that cereals (wheat, maize and sorghum) are good source of carbohydrates, fibre and contain some considerable amount of protein and ash, the low moisture content of the samples indicates their longer shelf life properties.
Based on the study it is therefore recommended that more of cereals grains should be produced by farmers and fortifications of cereals should be carried out this is to increase the nutrient of cereals and cereals based products such as bread, biscuits and some local available food products derived from cereals especially from wheat, maize and sorghum.
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