Effect Of Rapeseed Oil Production Conditions On Its Quality Safety And Comprehensive Quality

Rapeseed oil is one of the main edible oils in China.It has a unique flavor and rich flavor,which was very popular among consumers.During the production of rapeseed oil,it may be contaminated by risk components such as polycyclic aromatic hydrocarbons(PAHs),3-chloro-1,2-propanediol fatty acid esters(3-MCPD esters)and glycidyl acid esters(GEs),and vitamin E and sterol may also be lost.In this paper,the effects of process conditions such as roasting seeds,adsorption and deodorization on the production of PAHs,3-MCPD esters,GEs,vitamin E,sterols and flavors in rapeseed oil processing were studied.The optimum process conditions were determined based on the control and removal of PAHs.To provide technical support for improving the quality and safety of rapeseed oil.Ragrant rapeseed oil was obtained from roasted rapeseed under different conditions by pressing,precipitation and filtration.Detection of PAHs,3-MCPD esters,GEs,vitamin E,sterols,volatile flavor substances,acid value and peroxide value in rapeseed oil,and sensory evaluation.Study on the effects of roasted seed conditions on the risk components and nutrients in the production of concentrated rapeseed oil.The results showed that the content of benzo[a]pyrene(BaP)and PAH4(benzo[a]anthracene,chrysene,benzo[a]fluoranthene and benzo[a]pyrene)in rapeseed oil increased with the increase of the temperature of roasted seeds and the prolonged time.The temperature of roasted seeds does not exceed 180?,and the contents of BaP and PAH4 were lower than the EU limit.The time of roasted seeds was no more than 30 min,and the content of PAH4 was 1.89~8.98?g/kg,which was less than the EU limit.Based on the control of PAHs in rapeseed oil,it was recommended that the temperature of the roasted seeds does not exceed 180°C,and the time of the roasted seeds does not exceed 30 min.The 3-MCPD esters and GEs in rapeseed oil increased with the increase of roasting temperature and time.The content of vitamin E and sterol increased first and then decreased with the increase of roasting temperature.When the roasting conditions were 160°C and 20 min,rapeseed oil had strong aroma and no peculiar smell,and the highest score was obtained.The relative content of degraded glucosinotry products in volatile flavor compounds of roasted rapeseed oil was the highest.Among the heterocyclic compounds,pyrazines have the most species.The relative content of degraded glucosinotry products and pyrazine compounds were the highest and aldehydes the lowest at 160°C.Therefore,it can produce better flavor at 160°C.The acid value and peroxide value of rapeseed oil increased with the increase of roasting temperature and the prolongation of roasting time.The color of rapeseed oil deepened with the increase of roasting temperature and the prolongation of roasting time.Considering the safety quality,nutritional quality and flavor of rapeseed oil,the optimum conditions for roasting rapeseed oil was 160°C,20 min.Aiming at the possible risks of PAHs,3-MCPD esters and GEs in the production of ragrant rapeseed oil,the adsorption and removal technology of PAHs in Ragrant rapeseed oil was studied.Ragrant rapeseed oil was treated with H-2 activated carbon,Norit activated carbon,attapulgite and activated clay.The effects of four adsorbents on the removal of PAHs,3-MCPD esters and GEs from rapeseed oil and the retention of vitamin E,sterols and volatile flavor substances were analyzed.The results showed that Norit activated carbon had the best removal effect on PAHs,followed by H-2 activated carbon,and attapulgite had the worst removal effect.Activated clay and attapulgite had poor removal efficiency of 3-MCPD ester and GEs from rapeseed oil.When the addition amount of H-2 activated carbon was 0.5%,the content of 3-MCPD ester was the lowest,and the removal rate was 34.02%.When the amount of H-2 activated carbon was 2%,the removal rate of GEs was 91.16%.Adding 5% active clay and attapulgite resulted in more loss of vitamin E and sterol and lower sensory score.After H-2 activated carbon and Norit activated carbon treatment,the content of glucosinolate degradation products,pyrazine and furan were reduced,but the loss was less.Comprehensive consideration of the removal of harmful ingredients and the retention of flavor and nutrients,the optimal adsorption conditions were: H2 activated carbon was added in an amount of 0.5%,adsorption temperaturewas 100°C,and adsorption time was 35 min.At this time,the removal rates of BaP and PAH4 were 94.24% and 89.29%,respectively;the removal rates of 3-MCPD ester and GEs were 36.28% and 74.53%,respectively;the loss rates of vitamin E and sterol were 7.94% and 11.25%,respectively;sensory score 8.08.Rapeseed oil was deodorized by steam distillation at different temperatures and times.The PAHs,3-MCPD ester,GEs,trans fatty acids,vitamin E and sterols in rapeseed oil before and after deodorization were tested.Study on the effects of deodorization conditions on the safety quality and nutritional quality of rapeseed oil.The higher the deodorization temperature,the longer the deodorization time and the longer the removal effect on PAHs.The deodorization conditions were 270°C,120 min,BaP,PAH4,LPAHs,HPAHs and PAH16 removal rates were 45.10%,58.32%,82.71%,35.81% and 69.68%,respectively.The content of 3-MCPD ester and GEs increased with the increase of deodorization temperature when the deodorization time was fixed.Deodorization temperature exceeds 230°C,3-MCPD ester and GE content increase sharply.The deodorization temperature was 270°C,and the content of 3-MCPD ester and GEs reached the maximum at 60 min,which increased by 6.84 times and 27.19 times respectively.The deodorization conditions were 270°C,120 min,vitamin E,sterol loss was the largest,the loss rate was 28.31%,20.50%,and the trans fatty acid content was 3.21%.In order to reduce the loss of vitamin E and sterol in rapeseed oil and the formation of 3-MCPD ester,GEs and trans fatty acid,a two temperature deodorization experiment was carried out.The content of PAHs decreased with the increase of temperature in the high temperature stage.The BaP and PAH4 removal rates were 40.56% and 47.99%,respectively.when the temperature was 270°C.The content of 3-MCPD ester in rapeseed oil increased after different deodorization,and the content of GEs increased with the increase of deodorization temperature in high temperature stage.The content of 3-MCPD ester and GEs at 270°C increased by 1.53 times and 6.35 times respectively.The loss rate of vitamin E and sterol were 16.03% and 11.43%,respectively.The trans fatty acid content was 0.81%.Therefore,double temperature deodorization was beneficial to control the formation of 3-MCPD ester,GEs and trans fatty acid,and has better retention effect on vitamin E and sterol.