Study Of DNA Extraction And Detection Methods From Edible Oil

Edible plant oil is necessary in people's daily life.It can provide people with fats and energy.On the other hand,it contains much nutrition which is beneficial to consumers'health.The edible oil can be used for frying,baking,and other types of cooking because of its high boiling point.Its quality is not only related to the taste and color of food.On the other hand,poor quality edible oil also does bad to the consumers'health.It can be seen from the plant oil production and consumption in worldwide that plant oil becomes more and more important in global economy.With the improvement of people's living standard and economic level,food safety has attracted people's attention gradually.The safety of edible oil is an important aspect of food safety.We focused on the following two aspects:one is the identification of genetically modified oil.Consumers own the right to know and the right to choose.The other is adulteration which expired oil or low price oil may be added to normal oil or high price oil.There were many methods in oil research,mainly separating into physical and chemical detection and molecular biology detection.This paper mainly focused on the use of molecular biology methods to detect edible oil.Whether DNA could be extracted successfully was the key step of using molecular biological method to determine whether the edible oil contains adulterated or genetically modified ingredients.We collected all the DNA extraction and DNA detection method and different grades of rapeseed oil.The collected methods were used to extract DNA from the oil samples.And the extracted DNA was amplified by real-time PCR with rapeseed endogenous gene CruA.Five different extraction methods were chosen to apply in DNA extraction from plant oil by comparing the real-time PCR amplifying results.These five methods were modified emulsification method,Wizard~?Magnetickit,Resin kit,NucleoSpin~?Food kits and DNeasy~?food mericon kits.In the later research,25 oil samples with different kinds and grades were collected.The front five different methods were used to extract DNA from the oil samples.For all extracted DNA,the concentration and purity were measured by a Nanodrop 2000 spectrophotometer and at the same time real-time PCR was used to amplify the extracted DNA with endogenous genes of major oil-bearing crops and plant specific endogenous gene.DNA extracted by modified emulsification was the highest among all the DNA concentration and purity results.Its average concentration was about 1000 ng/?L.While there was salmon sperm DNA added inside so the DNA concentration was much higher than the oil crop DNA concentration.The concentration of DNA extracted by Resin kit was higher than the concentration of DNA extracted by other three commercial kits.DNA extracted by those commercial kits was not pure enough.There may be impurities left in the DNA solution.By analyzing and comparing the real-time fluorescence quantitative PCR results,the modified emulsification method was superior to the other four commercial kits.This study provides an important technical reference for the development of refined edible oil molecular biology detection and protection of edible oil safety.