Development and comparative study of determination of Escherichia coli in different processed products of Angelicae Sinensis Radix based on fluorescence quantitative PCR / 中草药

ABSTRACT

Objective: To make quantitative analysis for the quantity of Escherichia coli in Angelicae Sinensis Radix (ASR) and its processed products. Methods: The fluorescence quantitative PCR method was established to quantitatively analyze E. coli in ASR from different processed products, different producing areas, different enterprises and different storage time. Results: The number of E. coli in different processed products was ranked as follows: ASR > ASR stir-frying with soil > ASR stir-frying with wine. And the number of E. coli in the three producing areas of ASR in Min County of Gansu Province was less than that in other producing areas. Compared with the retail enterprises, the number of E. coli in ASR and ASR stir-frying with wine was less in production and sale enterprises. Different storage time had certain effect on the number of E. coli in ASR and ASR stir-frying with wine. With the increase of storage time, the number of E. coli also increased. Plate counting method and fluorescence quantitative PCR method were carried out at the same time for some representative samples. The results showed that the results of the plate counting method were mostly negative, and the results of the fluorescence quantitative PCR were positive. Conclusion: The quantitative fluorescence PCR method established in this paper is superior to the plate counting method in specificity, sensitivity, reliability, and reporting cycle, which can provide an effective method for rapid and accurate quantitative detection of E.coli in different processed products of ASR.