Factors Influencing the Occurrence of Methanethiol in Aqueous Slurries of Soy Protein Concentrates |
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| Authors: | Q. Lei W.L. Boatright |
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| Affiliation: | Authors Lei and Boatright are with the Animal Science Dept., Univ. of Kentucky, Lexington, KY 40546–0215. Direct inquiries to author Boatright (E-mail: ). |
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| Abstract: | : Aqueous slurries of 6 commercial soy protein concentrate (SPC) contained from 9.8 to 21.7 ppb methanethiol, which corresponds to odor values (in water) of 49 to 108. Effects of temperature (5.5, 24, and 65°C), pH (4.8,6.6, and 9.0), transition metals (FeCl3, FeCl2, and CuCl2), lipoxygenase, and EDTA on methanethiol levels in SPC slurries were investigated. Higher temperature (65°C), basic pH (9.0), transition metals, lipoxygenase, and EDTA caused significant increases in methanethiol compared with the control. CuCl2 caused greater increases in methanethiol than FeCl3 and FeCl2. In contrast, treatments with lower temperature (5.5°C) or acidic pH (4.8) resulted in lower levels of methanethiol in all commercial SPC samples examined. |
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| Keywords: | odor activity value methanethiol quantification GC-MS soy protein concentrates |
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