Min S, Yu Y, Yoo S, St Martin SK. Effect of soybean varieties and growing locations on the flavor of soymilk. J Food Sci 2005.
The volatile compounds of soymilk prepared from 5 soybean varieties grown in 2 locations were isolated and separated by a dynamic headspace analyzer and capillary gas chromatography. The coefficient of variation for the quantitative analysis of volatile compounds of soymilk by dynamic headspace analysis was less than 3.0%. Soybean varieties and growing locations had significant effects on the volatile compounds of the batches of soymilk at alpha = 0.05. The higher the soybean protein, the higher the volatile compounds in the soymilk. The correlation coefficient between the protein content and the volatile compounds of the milk was 0.99. Thirty-eight volatile compounds of soymilk were identified by a combination of mass spectrometry and gas chromatographic retention times of standard compounds. Most of the identified compounds were formed by the lipid oxidation of soymilk. However, 2-pentylfuran, dimethyl disulfide, and dimethyl sulfide were formed by singlet oxygen. The beany or green flavor that makes the soymilk unpleasant or unacceptable to many Westerners may be due to 2-pentylfuran, which is formed from linoleic acid by singlet oxygen. The beany flavor can be eliminated by processing the soymilk with a minimum exposure to light and air.