Abstract: Objective: This study aimed to establish a real-time PCR method for rapid detection of kidney bean components in Lotus seed paste product. Methods: Specific primers and probes were designed based on the highly conserved region of the pvsbe2 gene of Phaseolus coccineus L. Specificity was confirmedDNA amplification of lotus seeds and other starch-rich plants. In addition, 1 ng/μL DNA of kidney bean was gradually diluted to determine its sensitivity. The DNA template of a mixture sample which contained 1% kidney bean and lotus seeds was 10-fold diluted to verify the weight sensitivity. And this method and PCR were applied to determine market samples for further validation. Results: This method had a high specificity which displayed no cross reaction with lotus seeds and other starch-rich plants. The sensitivity for detecting kidney bean DNA concentration and the proportion of kidney bean component were 1 pg/μL and 0.01%, respectively. The detection results indicated that positive amplification appeared in kidney bean present in lotus-seed-paste moon cake, which conformed to the food labels. Conclusions: The real-time fluorescent PCR method established in this study has the characteristics of high specificity and sensitivity and is suifor fast detection of kidney bean component in lotus seed paste products.

Key words: Lotus seed paste product, kidney bean component, detection, real-time polymerase chain reaction