Evaluating the effect of lactic acid bacterial fermentation on salted soy whey for development of a potential novel soy sauce-like condiment

Rebecca Yinglan Zhou; Xin Huang; Zhihao Liu; Jian-Yong Chua; Shao-Quan Liu

doi:10.1016/j.crfs.2022.10.004

Evaluating the effect of lactic acid bacterial fermentation on salted soy whey for development of a potential novel soy sauce-like condiment

Curr Res Food Sci. 2022 Oct 7:5:1826-1836. doi: 10.1016/j.crfs.2022.10.004. eCollection 2022.

Authors

Rebecca Yinglan Zhou¹, Xin Huang¹, Zhihao Liu¹, Jian-Yong Chua¹, Shao-Quan Liu^{1

2}

Affiliations

¹ Department of Food Science and Technology, National University of Singapore, 2 Science Drive 2, 117542, Singapore.
² National University of Singapore (Suzhou) Research Institute, 377 Lin Quan Street, Suzhou Industrial Park, Jiangsu, 215213, China.

Abstract

There were two main objectives of this study: (1) to understand the effect of salt concentration on the growth of four lactic acid bacteria (LAB) in soy whey and determine the non-volatile and volatile profiles generated after fermentation; (2) to evaluate the potential of using salted soy whey to develop a sauce-like condiment through LAB fermentation. The four LAB included non-halophilic Lactiplantibacillus plantarum ML Prime, Limosilactobacillus fermentum PCC, Oenococcus oeni Enoferm Beta and halophilic Tetragenococcus halophilus DSM20337. At 2% salt, all LAB grew remarkably from day 0 to day 1, except for T. halophilus, while at 6% salt, the growth of L. plantarum, L. fermentum and O. oeni was suppressed. Conversely, the higher salt concentration enhanced the growth of T. halophilus in soy whey as the cell count only increased from 6.36 to 6.60 log CFU/mL at 2% salt but it elevated from 6.61 to 7.55 log CFU/mL at 6% salt. Similarly, the higher salt content negatively affected the sugar and amino acids metabolism and organic acids production by non-halophilic LAB. L. plantarum and O. oeni generated significantly (p < 0.05) more lactic acid (3.83 g/L and 4.17 g/L, respectively) than L. fermentum and T. halophilus (2.02 g/L and 0 g/L, respectively) at 2% salt. In contrast, a higher amount of acetic acid was generated by L. fermentum (0.72 g/L at 2% salt) and T. halophilus (0.51 g/L at 6% salt). LAB could remove the green and beany off-flavours in soy whey by metabolizing C6 and C7 aldehydes. However, to develop a novel soy sauce-like condiment, yeast fermentation and Maillard reaction may be required to generate more characteristic soy sauce-associated aroma compounds.