Effect of insect infestation on the organoleptic characteristics of stored cereals

Abstract

Two major pests of stored cereals in tropical and subtropical regions of Asia and Africa, Rhizopertha dominica Fabricius and Trogoderma granarium Everts, were used in experiments to investigate the effect of insect infestation on organoleptic characteristics of stored cereals. Infestations were achieved by releasing the two insect species either singly or in mixed populations in samples of wheat, maize and sorghum. These releases resulted in infestation levels of 25, 50 and 75%. ‘Chapatis’ made from infested and uninfested grain flours were evaluated for colour, taste, texture, aroma and appearance by a panel of semi-trained judges. There were no significant differences in the scores for colour, appearance, aroma and texture at all infestation levels for all three cereal grains and the scores also did not differ significantly from uninfested grains. However, at 50 and 75% infestation levels, scores for the taste of chapatis of three cereal grains were significantly ( P < 0.05) lower than uninfested grains. Bitter taste also resulted in poor overall acceptability of chapatis prepared from flours infested at the 50 and 75% levels.