Development and optimization of an efficient method to detect the authenticity of edible oils

The authenticity of edible oils has recently attracted increased attention, particularly due to the emergence of swill-cooked dirty oil. There has not been an effective method to detect the authenticity of edible oils due to the diversity of edible oils, the trace DNA in oils and serious DNA degradation. In this study, an efficient method was developed and optimized to detect the authenticity of edible oils. The stability and efficiency of detecting the authenticity of edible oils were dramatically increased by the DNA extraction method, amplification fragment selection and nano-real time PCR. The DNA extraction method was optimized with regard to the type and the amount of organic reagent, the types and the amounts of extraction buffer, and the DNA carriers. The types of organic reagents and DNA carriers determined whether DNA could be successfully extracted from different edible oils. The amount of DNA extracted from edible oils and adulterated edible oils with the optimized extraction method was evaluated by real-time PCR with different amplification fragments and nano-real time PCR. The results showed that 10 mL soybean oil can be detected against a background of 40 mL sesame oil. Additionally, the new nano real-time PCR technology was applied to amplify the DNA in edible oils at the first time. The efficiency and the precision of the PCR were dramatically increased by gold colloid. The results from this research are beneficial for detecting the authenticity of edible oils.