Metabolite changes of mung bean milk analogue following germination and/or fermentation with probiotic Limosilactobacillus reuteri

As interest in plant-based milk analogues increases, as will the demand for nutritionally and sensorially improved milk analogues. With mung bean milk analogue having a similar mineral and amino acid composition to that of bovine milk, its nutrient and flavour makeup could potentially be further enhanced. This study explored the modulation of mung bean milk analogue substrates and metabolites through germination (GM), fermentation (FM) with a probiotic strain of Limosilactobacillus reuteri, and the combination (GFM). Physicochemical parameters and constituents including raffinose, organic acids, amino acids, vitexin and volatiles were assessed. Raffinose was reduced to undetectable levels following either GM and/or FM. GFM had a 4-fold increase in lactic acid compared to FM, while GM led to significant increases in the amino acid content. Interestingly, the lysine content was modulated by both GM and FM, where either GM or FM elevated lysine to comparable levels, but GFM tripled the lysine content. The volatile profile was also greatly altered, where GM increased green odour volatiles, but FM and GFM counteracted it, reducing green aldehydes to trace levels. Different modifications to the constituents in mung bean milk analogue were found between the treatments. However, GFM yielded the most desirable compositional modification relative to both GM and FM, with elevated lysine content and reduction in green aldehydes, and should be further studied to accelerate plant-based milk analogue development.