水化脱胶对冷榨核桃油品质的影响OA

China has the largest area of walnut cultivation and the highest production in the world.The unsaturated fatty acid content in walnut oil is over 90％,and it is rich in lipid-as-sociated substances.Cold pressing can retain the nutritional components of walnut oil to the greatest extent,but the phospholipids in cold-pressed walnut oil can affect its stability and quality.Hydration degumming is a simple and effective method to remove phospholipids from crude oil,but the impact of hydration degumming on the retention of lipid-associated sub-stances and the generation of lipid risk factors in crude oil is still unclear.This study aims to reveal the effects of hydration degumming on the physicochemical properties,fatty acid com-position,glyceride composition,triglyceride composition,retention of lipid-associated sub-stances and generation of lipid risk factors in cold-pressed walnut oil.The results showed that the acid value of walnut oil increased from 0.32 mg KOH/g to 0.45 mg KOH/g after degumming,and the peroxide value increased from 0.061 g/100 g to 0.068 g/100 g.The pro-portion of unsaturated fatty acids before and after hydration degumming was 91.99％and 89.39％,respectively,with no significant difference(P＞0.05).The content of each compo-nent of glycerides remained basically unchanged,and the molecular types of triglycerides were basically the same.The study found that oleic acid and linoleic acid were the main com-ponents at the sn-2 position of triglycerides,accounting for 86.27％.Some lipid-associated substances were lost in small amounts,with vitamin E(expressed as α-tocopherol equiva-lents)decreasing from 5.4 mg α-TE/100 g to 3.45 mg α-TE/100 g(retention rate of 63.89％),and β-sitosterol decreasing from 1 251.7 mg/kg to 1 055.1 mg/kg(retention rate of 84.29％).Squalene was not detected before and after hydration degumming.Two plasticizers,di butyl phthalate and di(2-ethylhexyl)phthalate,were not detected.3-monochloropropane-1,2-diol esters and glycidyl esters decreased from 0.30 mg/kg and 0.16 mg/kg to 0.29 mg/kg and 0.15 mg/kg,respectively.The study shows that hydration degumming can cause a slight increase in acid value and peroxide value,with no significant difference in the composition of fatty acids and glycerides(P＞0.05),but it can cause the loss of vitamin E and β-sitosterol,and remove some lipid risk factors.This study provides theoretical support for the production of high-quality cold-pressed walnut oil.