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soya bean oil
I. Introduction
Soybean oil is a kind of oil extracted from soybean, which has a certain viscosity and is translucent liquid. Its color varies with soybean seed coat and soybean variety, from light yellow to dark brown, with soybean flavor.
Second, the characteristics
Physicochemical constants of soybean oil:
Relative density (d20℃4℃) 0.9 150-0.9375
Refractive index (N20℃ d)1.4735-1.4775
The viscosity (E020℃) is about 8.5.
Freezing point (℃)-18~- 15
Iodine value (g iodine/100g oil) 120- 137.
Saponification value (mgKOH/g oil) 188- 195
Total fatty acid content (%) 94.96
The average molecular weight of fatty acids is about 290.
Composition of soybean oil
Fatty acid composition of soybean oil
Component content (%) Component content (%)
Palmitic acid 6-8 oleic acid 25-36
Stearic acid 3-5 linoleic acid 52-65
Peanut acid 0.4-0. 1 linolenic acid 2.0-3.0.
Soybean oil contains a lot of linoleic acid. Linoleic acid is an essential fatty acid for human body and has important physiological functions. Children lack linoleic acid, the skin becomes dry, the scales thicken, and the development and growth are slow; The lack of linoleic acid in the elderly will cause cataracts and cardiovascular and cerebrovascular diseases.
Soybean crude oil has a fishy smell, which can be removed after refining, but it has a tendency of aftertaste during storage. The fishy smell of soybean is caused by linolenic acid and linolenic acid. The "aftertaste" phenomenon of soybean oil can be basically eliminated by minimizing the linolenic acid content and avoiding the formation of linolenic acid by selective hydrogenation.
When refined soybean oil is stored for a long time, its color will change from light to dark, which is called "color recovery". The color recovery of soybean oil is more obvious than other oils, and the complex changes caused by automatic oxidation of oils may be the basic reason. This phenomenon can be prevented by reducing the moisture content of raw materials, which is widely used and basically solves the color of soybean oil.
Baidu encyclopedia soybean oil