| The soybean varieties and soymilk have been studied systematically, rearch on the characteristics of different LOX-lacking soybean material, the effect of soybean material to the soymilk quality, the effect of critical craft to the soymilk quality, the soymilk product, so as to give the theory gist for no beany-flavor soymilk process.Zhongte No.1" was identified as lipoxgenase-1,2,3 null mutant soybean variety by means of isoelectric focusing-olyacrylamid gel electrophoresis(IEF-PAGE) on the processing characteristic of different types of lipoxygenase lacking soybean varieties. Also had the quantitative analysis by the LOX activity determination, and the LOX activity of "Zhongte No.1" was 4.12×105, and the "Heinong 35" was 2.6×106, "Zhongte No.l" was the 15.8% to "Heinong 35".More than 50 types of compound were found by GC-MS combining solid phase micro-extraction, the primary beany-flavor or total amounts of the beany-flavor as well as the total volatiles have been confirmed that the soymilk made of "Zhongte No.1" had the lowest comparing other soybean materials. They were 7.61, 8.41 and 12.27ppm respectively. But the contents of "Heinong 35" were 20.39. 25.30 and 38.47ppm respectively. The contents of flavor compounds from "Zhongte No.l" have much lower than "Heinong 35" about 12.78, 16.89 and 26.2ppm respectively.The content of Ve from "Zhongte No.l" soymilk were the highest after blending with none treatment, gained 93.21 μg·g-1, "Heinong 35" were the lowest only 42.76μg·g-1. After 1 min blanching time, the contents of VE from "Zhongte No.1" soymilk gained 126.35μg·g-1, "Zhonghuang 18" and "Wuxing No.l" were 108.07 and 128.75μg·g-1. but normalo soybean "Heinong 35" was only 71.75μg·g-1. Using heat treatment, the contents of VE from "Zhongte No.1 "lost few at 70 ℃ of blending condition, reached as high as 126.35μg·g-1, but "Heinong 35" reduced at 90℃ of blending condition and the content only was 85.70μg·g-1. The content of VE from "Zhongte No.1" soymilk had about 47.43% much higher than "Heinong 35".LOX could result in lipid oxidation, the value of TBAS increasing. The results showed that "Zhongte No.l" got the lowest TBAS values as 15.48μg·mL-1 which soybeans were treated in the same condition. Whatever the temperature of blending condition the TBAS value maintained on the low level at 4.5μg·mL-1 if the soybean were blanching for 1min, but "Heinong 35" after 6min heat treatment TBAS values still achieved 5.1 μg·mL-1. "Zhongte No.1" was blanching in lmin or blending at 70℃ the activity of LOX achieves about 5×104, but "Heinong 35" was blanching in 4min or blending at 90℃ the activity of LOX still maintained about 1 × 105.The "Zhongte No.1" had good process characteristics on flavor, VE, TBAS and the activity of LOX. Take "Zhongte No.l" soybean as the raw material, the soymilk process of critical craft was researched. The optimal craft condition were: soaking in 0.6%NaHCO3 at normal temperature for 8h, lmin blanching and 70℃ blending condition, gained the highest contents of protein which were 4.8g·100mL-1, the soluble solids achieved 6.4% maximum value, LOX dropped 58.33% and the TBA value dropppedto 4.5 ug-mL"1, the production of soymilk had the good flavor.Two types of soymilk procductions have been researched and developed. The primary taste soymilk appended 0.2% glycerol monostearate, 0.01% xanthan gum or 0.05% CMC, after two times homogenizing, sterilization resulted in the homogeneous product and the flavor was good. Pumpkin soymilk was made by 3 quantum pumpkin juices to 7 quantum soymilk, appended 9% sugar, 0.15% glycerol monostearate and 0.04% xanthan gum or 0.17% glycerol monostearate and 0.021 % CMC, after two times homogenizing and the sterilization, the product had both soymilk and pumpkin good flavor.
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