Effects of grain drying methods on postharvest insect infestation and physicochemical characteristics of maize grain

Abstract

AbstractIn this study, the storability of maize that dried using a newly designed solar bubble dryer (SBD), solar cabinet dryers (mixed and indirect), and open sun drying at two sample loads—thick layer (21.74 kg/m2) and thin layer (10.87 kg/m2) were evaluated. The dried maize grains were stored in four different farmer houses for 6 months. Storage loss of the grain was recorded over 6 months, at an interval of 2 months. The chemical compositions and germination capacity of dried maize were assessed after drying. The results revealed that significantly lower mean values of total live insect counts, percentage weight loss, percentage of insect‐damaged kernels, and percentage loss of bulk density were recorded in thin layer dried maize across all storage periods. Drying methods posed significant effect on the total live insect count up to 4 months of storage, the lowest number was observed for open sun and solar bubble‐dried grain. Percentage germination was significantly affected by the amount of sample load. The present study showed that drying can slow down insect population development and associated losses during storage. Therefore, SBD can be promoted as part of integrated postharvest handling technique to reduce postharvest loss of maize.Practical ApplicationsPercentage of grain postharvest losses in developing countries is very high. Grain drying and storage are the two most important postharvest activities to control grain loss before and after storage. In this study, storage insect susceptibility of maize grain dried with different types of solar dryers (solar bubble, solar mixed and indirect cabinet, and open sun) is presented. Gains that were dried in thin layer manner were less infested by the maize weevil, Sitophilus zeamais Motschulsky, than thick layer. The physicochemical properties of maize grain were not significantly affected by each of the drying methods. This study will be useful for smallholder farmers and agricultural cooperatives in giving a sustainable and low cost drying technology and showing the optimum drying conditions to reduce grain loss. It will also be helpful for food processing industries to produce safe and high quality products.