| In order to study the effects of soybean raw materials on oil quality, Soxhlet extraction method was used to extract oil from immature and mature soybean in the same batch, and the differences in physicochemical indexes, glyceride and fatty acid composition, trace components composition and contents,and low temperature crystallization characteristics of immature and mature soybean oil were analyzed. The results showed that the acid value, peroxide value, anisidine value, total oxidation value and conjugated diene value of immature soybean oil were significantly higher than those of mature soybean oil. Compared with mature soybean oil, the contents of disaturated monounsaturated fatty acid triglyceride in immature soybean oil increased by 22%， the contents of saturated fatty acids of triglyceride, monoglyceride, 1,2-diacylglycerol, 1,3-diacylglycerol in immature soybean oil increased by about 12%, and the content of diacylglycerol was 1.4 times of that in mature soybean oil. The content of phospholipid acid in immature soybean oil was 3.2 times of that in mature soybean oil, the contents of total tocopherol and total sterol decreased by 8.2% and 13.0% respectively, and the chlorophyll content was 206.3 times of that in mature soybean oil.In addition, immature soybean oil crystallized more easily than mature soybean oil, the turbidity time was earlier at 0 ℃, the solid fat content was larger at -20 ℃ and -15 ℃, and the temperature of microcrystalline formation and solid phase transition was higher, which might be related to the higher contents of saturated fatty acids, high melting point triglyceride and diacylglycerol.In actual production, the proportion of immature soybean in raw materials should be minimized to improve the quality of the finished oil. |
