| Effectiveness of tricalcium phosphate dust coatings on various surfaces in controlling 3 species of stored-product insects at 25 (+OR-) 2(DEGREES)C and 65 (+OR-) 5% r.h. was determined. TCP was most effective against Tribolium castaneum (Herbst), Tribolium confusum (Duvar), and Oryzaephilus surinamensis (L.) on tin and glass after 4 days exposure. The treatment was less effective on vinyl tile, and no significant mortality was observed on plywood. Complete mortality (100%) was not attained for any species on any surface at dosages up to 0.1 mg/cm('2) at 4 days exposure.;Cakes made from infested flour showed major changes after 2 and 3 months flour storage. These included a progressive reduction in volume, contour, grain quality, crumb pH, viscosity of both flour and crumb, and a progressive darkening and toughness of crumb. Levels of uric acid comparable to those excreted by the insects had no apparent effect on cake quality.;Tricalcium phosphate at 2% suppressed the development of large numbers of insects in cake flour. The low level infestation in treated flour after 3 months flour storage had no significant effect on cake quality and no uric acid was detected.;Tricalcium phosphate at 2% in flour slightly darkened crumb color, reduced flour viscosity and crumb firmness, but did not change specific gravity of cake batter or crumb pH. Volume, contour, grain quality, and crumb viscosity were initially reduced but, after 1 month flour storage there was no apparent effect on volume and contour. After 2 and 3 months storage there was no apparent effect of TCP on crumb viscosity or grain quality.;Quality of layer cakes made from flour with and without 2% tricalcium phosphate subjected to infestation by Tribolium castaneum (Herbst) were studied over a period of 3 months flour storage at 25 (+OR-) 2(DEGREES)C and 65 (+OR-) 5% r.h. Volume, contour index, grain quality, crumb firmness, crumb color, crumb pH and amylograph peak viscosity of flour and cake crumb were used to evaluate cake quality. |
