Postharvest losses in food grains – A Review

Grains (cereals and legumes) are universal foods that provide calories, proteins, essential minerals and vitamins. They are essential to the nutrition of many including infants and children. Attack by insects and microorganisms, particularly fungi, during drying, storage and processing, affects the quality, safety and market value of grains. Fungal attacks before or during drying can be disastrous, the effect can persist throughout the supply chain. Postharvest grain losses pose challenges to food and nutritional security, public health, and many developing nations' economy. Postharvest storage structures and packaging materials are expected to extend the shelf life of the grains by protecting them from insects, microorganisms, environmental factors and making the microenvironment unfavorable for insect and microbial activities. Traditional storage and packaging materials are highly inefficient in this sense and are associated with quality degradation. Traditional storage and packaging materials commonly used by farmers, mostly in developing countries, include granary, crib, wooden box, gunny bag and polypropylene woven bag. Modern storage and packaging materials commonly used are metal silo and hermetic bags; they are effective but unfortunately cannot be afforded by most farmers in developing countries. The article reviewed postharvest storage management of cereals and legumes. Literature was gathered through a comprehensive literature review. The use of various traditional storage and packaging materials for grains was debated. Techniques for the prevention of postharvest losses were extensively discussed, emphasis was given to novel technology and the use of natural insecticides. Challenges associated with controlling postharvest losses were also summarised. In the end, research gaps were identified and recommendations were provided about minimizing grain contamination and postharvest losses.