Reducing of lipoxygenase and trypsin inhibitor in soy milk for improving nutritional quality through atmospheric cold plasma pretreated soybeans

Soy is one of the most popular plant proteins. However, lipoxygenase (LOX) and trypsin inhibitor cause the undesirable beany odor and hinder trypsin activity. While thermal processing is commonly employed, it poses a risk of damaging heat-sensitive nutrients. To investigate the effects on lipoxygenase, trypsin inhibitor, and improve nutritional quality of soy milk, soybeans were treated with atmospheric cold plasma (ACP). After plasma treatment, lipoxygenase activity decreased by 97.82 %, and trypsin inhibitor activity decreased by 66 % from 61.56 TUI/mg to 20.72 TUI/mg. Additionally, the raw soy milk made from cold plasma-pretreated soybean showed a significant increase in gallic acid, genistein and antioxidant activity, resulting in reduced lipid and protein oxidation compared to thermal processing-treated sample. In conclusion, cold plasma treatment was effective in reducing lipoxygenase and trypsin inhibitor activities while maintaining heat-sensitive nutrients, which could be used in the production of soy and other plant-based products.