Comparison of ELISA and fragment count methods for detection of insects in wheat flour.

Abstract

AbstractIn the research reported, the ELISA method used to detect the insect muscle myosin was tested and compared with a traditional method of counting insect fragments in flour using acid hydrolysis. One kilogram samples of wheat were infested with 0, 1, 2, 4, 8, and 16 adults of Rhyzopertha dominica, and milled to obtain wheat flour. The samples were analysed according to the AOAC method and by the immunoassay kit to detect myosin. The numbers of insect fragments detected by both methods were proportional to the infestation level. The number of insect fragments ranged from 4.4 in the lowest infestation level, to 73.2 in the highest infestation level. The lowest detection level of the immunoassay was 0.5 insects/50 g sample, and the maximum was 10 insects/50 g sample. The ELISA test represents a valuable tool for screening insect infestation in stored wheat kernels and flour to monitor sanitary quality, but modifications are required to increase the kit sensitivity for the lesser grain borer and other insects.