Efficacy of some plant products against losses of food commodities from storage pests

Abstract

Pest management of stored food commodities is still a serious issue in major parts of the world. In India, inadequate storage facilities and subsequent pest attack by insects and fungi cause a loss of about 10-40% wheat and chickpea annually. Callosobruchus chinensis L. (Coleoptera: Bruchidae), the adzuki bean weevil, and Sitophilus oryzae L. (Coleoptera: Curculionidae), the rice weevil are the major biodeteriorating insect pests of legumes and cereals respectively causing serious losses- damaging up to 32-64% of stored chickpea and wheat respectively in Asia and Africa. In addition, food-borne molds and their toxic metabolites cause quantitative and qualitative deterioration of nearly 25% of agricultural food items throughout the world. The mycotoxins secreted by different food borne fungi potentially induce various health problems in consumers. Moreover, lipid peroxidation of food items during storage due to the chain reactions of free radical oxidation is another major problem for qualitative losses of foods as the oxidized lipid can be harmful to humans. Metabolic products of aflatoxin B1 (AFB1-8,9-exoepoxides) have also been reported responsible for stimulating lipid peroxidation by enhancing highly reactive ROS molecules. Currently exploration of phytochemicals or plant products to replace harmful synthetic pesticides/preservatives are gaining momentum by the agricultural industries so as to formulate some novel plant based pesticides/preservatives for the management of infestation of food items during storage. Plants pose a number of defensive secondary metabolites viz. terpenoids, phenolics, alkaloids etc. being used by them since antiquity for their protection against herbivores and pathogens newline