Proximate Composition of Ten Types of Biscuits and their Susceptibility to Tribolium castaneum Herbst (Tenebrionidae: Bostrichidae) in Nigeria

Abstract

Ten biscuit types namely Tea, Digestive, Butter Scotch, Cream Cracker, Coaster, Fibre Plus, Shapes, Gin-Gin, Cabin and Crunchy were examined for their proximate composition and susceptibility to Tribolium castaneum Herbst. The biscuit samples had proximate composition ranging from 4.9 - 5.5% moisture content, 8.6 - 12.0% crude protein, 3.4 – 4.8% ash, 15.4 – 24.0% fat, and 55.4 – 64.0% carbohydrate and 2.09 - 2.81% crude fibre. Assessment of the biscuit types for susceptibility test was based on percentage adult mortality, mean number of adult emergence and percentage weight loss. Results showed that there were significant differences (P<0.05) in the parameters studied. Fibre Plus biscuit had significantly (p<0.05) lower mortality of T. castaneum adults, higher level of adult emergence and the most weight loss of 53.0% as a result of insect infestation within 120 days after infestation. Results showed that the biscuits were susceptible to T. castaneum infestation particularly if not properly packaged or preserved. Apart from proper preservation, biscuits should be supplemented with protein-rich diets to meet the nutritional needs of consumers.

Keywords: Composition, emergence, mortality, susceptibility, weight loss, T. castaneum