Research On PCR Safety Monitoring Technology Of Oil And Products

Sesame is a commonly used oil crop in China,with unique flavor and relatively high nutritional and medicinal value.Sesame seeds contain large amount of impurities,the sesame gap during storage is small,and the permeability is poor.In the high temperature season,it is easy to absorb moisture,and mildew occurs.Aspergillus flavus is one of the major contaminating fungi.Aflatoxins,mainly produced by molds such as Aspergillus flavus and Aspergillus parasiticus,are class 1 carcinogens.Aflatoxin is a metabolite of Aspergillus flavus.By identifying the Aspergillus flavus DNA in sesame oil by PCR,it can be determined whether the oil sesame is contaminated with Aspergillus flavus,and the contamination of aflatoxin in sesame oil can be determined.This method has the advantages of low requirements for equipment,short time,easy operation and relative safety.The issue of the safety of genetically modified foods has always been the focus of attention and discussion of people around the world,to this end,China has established a marking system to meet consumer’s right to know and consume.However,in addition to the mainstream big soybean products in the market,such as well-known brands of soybean oil,has signs of genetically modified products in accordance with national standards,Other soy products such as small-sellers,such as freshly squeezed soymilk and dried legumes,have not yet been supervised by a complete monitoring system and need to establish a monitoring technology system to strengthen supervision and it is necessary to establish a monitoring technology system to strengthen its supervision.In this paper,the detection technology of Aspergillus flavus contamination in sesame oil and the detection technology of transgenic components in soybean products were established with DNA as the target,and the following conclusions were obtained.1.The CTAB method,SDS method,and kit method commonly used in laboratories,as well as the SDS method that has been modified by the traditional SDS method,were compared and analyzed.It was concluded that the improved SDS method has higher quality of extracted DNA than the other three methods.The improved extraction method of this experiment has been optimized compared to the previous improved extraction method,saving a large part of the experimental time,and also making the experimental steps more concise and perfect.2.PCR was used to extract DNA from pressed sesame oil and soybean oil of different storage durations,and then PCR was performed using primers of different lengths.It was concluded that under conditions of crushing oil,DNA was not easily preserved and the degradation was rapid with time.3.Artificially contaminate the freshly sterilized sesame with a certain amount of Aspergillus flavus,and then mix well and gradually dilute serially to find the lowest PCR detection line for Aspergillus flavus in sesame oil was 4.97E-09 g/g。.4.PCR was used to design primers for soybean exogenous gene CaMV35 S,NOS termina tor and endogenous gene Lectin,and a PCR method for the detection of transgenic soybeans was established.The testing of 30 unmarked soy products in different districts of Zhengzhou s howed that 33.3% of soy products contain genetically modified components.