Development and validation of ultrafast PCR assays to detect six species of edible insects

Abstract

With the increasing use of insects as a food source, specific and sensitive detection methods for edible insects are required. To detect six insects (silkworm, mealworm, two-spotted cricket, rice grasshopper, white-spotted flower chafer beetle larvae, and rhinoceros beetle larvae) that have been approved for food consumption in Korea, an ultrafast PCR system was developed based on a microfluidic chip. Insect species-specific primer sets for the identification of the six edible insects were selected targeting the mitochondrial cytochrome c oxidase subunit I (COI) gene, and estimated for their specificity against 10 species of insects, which amplified only target insect species. The sensitivity of each primer set was independently validated in triplicate and was as little as 1 pg of DNA extracted from all insects. A total of 16 commercially processed products were used to verify the availability of these assays and to monitor the presence of labeled insect species. The ultrafast PCR assays developed in this study take approximately 20 min, and additionally confirm target species through post-PCR melt curve analysis. Thus, six species of edible insects could be rapidly and accurately identified in commercial food products using specific and sensitive ultrafast PCR methods.