Effects of heat treatment and β-cyclodextrin addition on soymilk flavor

Abstract: Flavor is an essential indicator to evaluate the quality of soymilk products, but the effects of heat treatment and β-cyclodextrin addition during soymilk processing on the entire flavor quality are not clear. In this study, the changes in the contents of critical soymilk flavor compounds during heat treatment (30-90 ℃) were investigated, and then the flavor profiles of soymilk with the addition of β-cyclodextrin (0.25%, 0.50%, 0.75%, 1.00%) at different heating periods (before heating, at 40℃, at 60 ℃, after heating) were analyzed. Results showed that, different flavor compounds varied in the sensitivity to temperature, and as the temperature increased during heat treatment, the intensity of beany flavor tended to decrease, whereas non-beany flavor was relatively enhanced. β-cyclodextrin addition could decrease the contents of critical soymilk flavor compounds, and a high concentration of β-cyclodextrin (≥0.50%) added at 60 ℃ led to the most significant decrease in the contents of critical beany flavor compounds including hexanal, hexanol, 1-octen-3-ol (P＜0.05), but trans-2-octenal, as the critical non-beany flavor compound, also suffered the greatest loss. Similar tendency was obtained according to the scores of beany odor, mushroom flavor, and sweet aroma by sensory evaluation, and the results of comprehensive scoring indicated that, the soymilk with the addition of 0.75% β-cyclodextrin at 60 ℃ during heat treatment had the best flavor quality. Since β-cyclodextrin is low-priced and safe, and the addition during soymilk processing is also easily practiced, it can be well applied in soymilk production for the improvement of flavor quality.