**1. Introduction**

The cereals are monocotyledons while the legumes are dicots. The cereal belongs to the grass family with more than 300,000 species. Furthermore, more than 190,000 species are angiosperms that are economically viable horticultural plants; and there are approximately 50 different types cultivated throughout the world in which about 51 species are grown. However, cereal's contribution to human nutrition cannot be overemphasized as it had been estimated that nearly 18 species of cereals cultivated provide more than 91% of the food supply to the world population. The cereals cover about 74% of the total tilled land surface. It had been estimated that more than 50% of the protein needs of the world population are provided by cereals [1, 2]. Currently, France ranks first in the Export of cereals such

as wheat, rice, maize, and barley in Europe but 5th in the production of wheat in the world [1, 2]. Other cereals include millet, sorghum, rye, oats, etc. The major grains such as wheat, rice, and corn add up to make three-quarters of the worldwide production of grain [1, 2]. Therefore, cereal grains remain the main source of dietary carbohydrates for the supply of vital food energy to the diet [1, 2]. Although cereal grains, such as maize, rice, millet, and wheat are mostly in higher demand for energy provision, other cereals also provide very important food uses while there are more researches to explore the underutilized ones [3]. When cereal crops are grown for the edibility of their fruits, they are referred to as *grains* (botanically called *caryopsis*).

Structurally, the cereal seed is composed mainly of two components; the *endosperm* and the *embryo* (*germ*). The endosperm (more than 90% 0f the bulk seed) provides the energy. The pericarp (outer wall) develops from the ovary wall and encloses the endosperm. Beneath the pericarp is the testa (a selectively permeable layer) that borders the embryo which is a product of the inner reproductive gland (ovary wall). The permeability of testa to water is high and aids in seed germination but in the presence of salt, the testa may lose its vigor which would consequently lead to nongermination of seeds planted in soils with dissolved salts. The aleurone layer (with thick-walled cells) is free of starch and is the third important layer of cereal grain. Both testa and pericarp are called the bran. Conversely, legumes are flowering plants (dicotyledons) in the Leguminosae family and were derived from the latin word *legere* (to gather) and *legumen* (seeds harvested in pods) during the mid-17th Century. It includes chickpea, black gram, mung bean, and pigeon pea which have an estimated 16,000–19,000 species in 750 genera. Asia ranks first both in area harvested and in production capacity. India, on the other hand, accounts for 75 and 96% of the total global production of chickpea and pigeon pea, respectively [4]. The expression *food legumes* usually mean the immature pods and seeds as well as mature dry seeds used as food by humans. Based on Food and Agricultural Organization (FAO) practice, the term *legume* is used for all leguminous plants. Legumes such as French bean, lima bean, alfafa, or others that contain a small amount of fat are termed *pulses*, and legumes that contain a higher amount of fat, such as soybean and peanuts, are termed *leguminous oilseeds*. Legumes represent an important source of food in developing countries. Soybean, groundnut, dry bean, pea, broad bean, chickpea, and lentil are the common legumes in most countries. In some countries, depending on the climatic condition and food habits, other legumes are grown. Legumes are next to cereals in terms of their economic and nutritional importance as human food sources [3]. They are cultivated not only for their protein and carbohydrate content but also because of the oil content of oilseed legumes such as soybeans.

Legumes are sources of protein and are relatively costlier economically compared to cereals with great food value; and are reasonable nutrients for the maintenance of the body, e.g., vitamins and minerals. The legume has almost the same energy value per unit weight compared to the cereal grains (4.2 kcal), albeit, they provide more calcium, iron, thiamine, riboflavin, pantothenic acid, among others than cereals. The utilization of legumes is highest in India and Latin America owing to religious restrictions and food attitudes. Legumes also contain some anti-nutritional factors, such as trypsin and chymotrypsin, phytate, lectins, polyphenols, flatulence-provoking and cyanogenic compounds, lathyrogens, estrogens, goitrogens, saponins, anti-vitamins, and allergens. However, heat treatment is known to destroy the anti-nutrients, such as protease inhibitors and lectins, although it also destroys vitamins and amino acids. Legumes are a good source of dietary fiber; the crude fiber, protein, and lipid components have a hypocholesterolemic effect.

#### *Postharvest Preservation Technology of Cereals and Legumes DOI: http://dx.doi.org/10.5772/intechopen.102739*

Healthy cereal grains and legumes are the demanding enterprises of the recent era for the production of high yield in the next season. The cereal grains and legumes must be properly stored for the maintenance of a high-yielding crop. Losses of high magnitude are encountered during storage that is due to biological and non-biological agents. The incidence of high losses of cereals and legumes after harvest in many countries of the world could account for the food security issues such as malnutrition, diabetes, and hunger which are counterproductive to mitigating efforts towards the improvement of food security. The effect of low yield, poor quality of produce, and the prevalence of chemical toxicants and mycotoxin contamination are significant problems that militate against the genuine and concerted efforts to improve postharvest losses (PHLs), provide appropriate handling and processing technologies for improved postharvest opportunities. In an attempt to maintain high-quality crops during postharvest operations (PHOs), care must be taken during harvesting to minimize damage and ensure appropriate postharvest handling techniques. Reliable methods for the assessment of postharvest losses should be developed while the use of the appropriate techniques to minimize loss and ensure the quality and safety of crops that meet quality standards are desired. In developing countries, Nigeria inclusive, cereals and legumes produced mainly by small-scale farmers are produced and stored on farms [4]. Biological and non-biological agents have been implicated in the postharvest losses of cereals and legumes (**Figure 1**) [5, 6].

There is a direct correlation between plentiful harvest and postharvest spoilage. In countries with huge harvests, postharvest losses are higher than in countries with less bumper harvests which may be a consequence of a lack of care arising from a short supply of laborers to preserve the excess grains. Consequently, farmers may be forced to sell their grains at a less reasonable price during the harvesting season to prevent possible postharvest losses. The glut in the price of cereals and legumes could lead to short supply leading to increased losses arising from insect pest attacks (*Prostephanus truncates).* However, the effect of bumper harvests on losses had not been measured, and overall; the effect would be minimal compared with the losses resulting from an unfavorable climate at harvest. Certainly, farmers are often supplied with sufficient storage capacity in developed countries so that at least

**Figure 1.** *Considerations for postharvest preservation technologies.*

good harvests can be accommodated in fixed stores; unlike in developing countries where less attention is paid to farming and facilities for storage are lacking. In such instances, farmers are content to store surplus cereals and legumes in sacks in their houses. In most cases, especially, in locations where subsistence farming is common, the use of bag storage rather than traditional structures is practiced.

It was strongly believed by the 1970s that postharvest losses (PHLs) at the farm level were high due to traditional practices. However, traditional practices are unlikely culprits as farmers have survived more difficult conditions over long periods by adapting their practices to the situational challenges [7]. Nonetheless, compelling losses do sometimes occur that could be due to agricultural developments for which the farmer is not versed due to nonavailability of extension agents. Among these agricultural developments is the introduction of high yielding varieties that are more susceptible to pest damage, additional cropping seasons that result in the need for harvesting and drying when weather is damp or cloudy or farmers producing significant surplus grains, and because it is to be marketed rather than consumed by the household, the farmer failed to provide the necessary storage facilities for the preservation of the surplus grains.
