Effect of Soybean Varieties and Growing Locations on the Flavor of Soymilk

Abstract

: 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 α= 0.05. The higher the soybean protein, the higher was the volatile compounds of soymilk. 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 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.

Chemical and physical composition of grain-type and food-type soybean for food processing

“…The hexanal and fatty acids contents were determined by gas chromatography according to the Min et al (2005) and Rayford et al (1994) methods, respectively. The gas chromatograph (HP 6890, Hewlett Packard, USA) was equipped with a silicone capillary column (30 m length, 0.32 mm diameter and 0.2 µm thick film) (SP 2340, Supelco, Sigma-Aldrich, USA).…”

Effect of harvest at different times of day on the physical and chemical characteristics of vegetable-type soybean

“…The content of fatty acids was determined by gas chromatography (GC) according to Rayford et al (1994) and Min et al (2005) using a gas chromatograph (Hewlett Packard brand -model 6890) with sample auto-injector and equipped with silica capillary column (30 m long, 0.32 mm internal diameter and 0.2 mm in film thickness) (Supelco brand -Model SP 2340). The analysis was conducted by isothermal chromatography at 190 °C with a flame ionization detector with a temperature of 300 °C and injector set at 250 °C.…”

Relationships among sensory analysis, isoflavone and hexanal contents of soymilk powder

“…Wilkens and Lin (1970) concluded that hexanal was the major volatile component in soymilk and the typical green-beany flavor. Min et al (2005) observed that most of the identified compounds were formed by the lipid oxidation of soymilk and the beany or green flavor that could make the soymilk unpleasant due to 2-pentylfuran formed from linoleic acid by singlet oxygen. Isoflavones and saponins are associated with astringency and bitterness (Okubo et al, 1992).…”