Edible Safety Evaluation Of Rapeseed Oil Extracted By Pulsed Electric Field

Pulsed electric field(PEF)technology is an emerging green and environmentally friendly non-thermal processing technology.At present,PEF technology has been widely used in sterilization and enzymatic passivation of liquid materials,thawing foods,refreshing fruits and vegetables,extracting juice and natural oil,improving juice flavor and nutritional components,etc.At present,some studies have found that PEF treatment has different effects on the oxidation degree of oil,and then affects the quality of oil.In order to investigate the effect of PEF,the change of physical and chemical quality of rapeseed oil was studied by accelerated oxidation test.The food safety was evaluated by acute toxicity test,subacute toxicity test and genotoxicity test.The main results are as follows:(1)PEF pretreatment affected the quality of rapeseed oil.PEF treatment made peroxide value,acid value,anisidine value,TBA value,carbonyl value and total peroxide value significantly higher than the control group.It can be obtained by accelerated oxidation experiment that the PEF pretreatment group had exceeded the national standard limits of all indicators at about 6 d,and had a slightly rancid taste on the 8th day;while the control group exceeded the national standard limit on the 8th day,and the rancid taste was produced on the 10th day.The values began to rise rapidly at times beyond the standard,and the value of the PEF pretreatment group was significantly higher than that of the control group at the same time(P<0.05).(2)PEF assisted extraction of rapeseed oil was determined to be non-toxic and safe.During the acute toxicity test in mice,there were no deaths and obvious poisoning,growth conditions were normal,eating conditions were normal,blood biochemical and blood routine indicators were not significantly changed,and liver and kidney tissue sections were not significantly changed.Mice were orally administered with LD50>40 g/kgb.w.;in the subacute toxicity test,there was no death and obvious poisoning in the mice,the growth status and eating status were normal,the blood routine indicators were not too significant changes,the liver and kidney tissue sections had no obvious lesions,and the blood biochemical indicators suggested that the males were small There were significant changes in liver-related indicators in some experimental groups of rats(P<0.05),but no obvious pathological changes were observed in the liver sections,and it was judged that there was no toxicity in a large amount of short-term continuous consumption;three groups of experiments,the Ames test,the mouse bone marrow micronucleus test and The sperm aberration test in mice were all negative,which means that no bacterial gene mutation,chromosomal damage,and germ cell mutation were caused,and there was no genotoxicity.(3)PEF treatment of rapeseed oil has certain effects of lowering blood lipids,lowering blood sugar and improving the level of antioxidant in the body.Through subacute toxicity test and in vivo antioxidant test,it was found that the experimental group of rapeseed oil reduced the TC,TG,HDLC and LDLC values to different degrees;the GLU value of some experimental groups was significantly lower than that of the blank control group(P<0.05);The superoxide dismutase(SOD)activity and glutathione(GSH-Px)activity in the serum,liver and kidney of the experimental group were significantly increased(P<0.05).The PEF pretreatment groups were slightly lower than the untreated groups but There was no significant difference,and the activity of malondialdehyde(MDA)in each group decreased significantly(P<0.05).The PEF pretreatment groups were slightly higher than the untreated groups,but there was no significant difference.