Utilization of a Bioinformatic Approach to Identify Emulsifying Peptides Embedded in Brewers’ Spent Grain Proteins and Characterization of Their Emulsifying Properties

Brewers’ spent grain (BSG) represents the major byproduct of the brewing industry and remains largely underutilized. While BSG contains a rather high amount of protein, poor functional properties limit its use as a functional ingredient for foods without additional processing. In this work, we investigate emulsifying peptides embedded in the major BSG proteins based on a mass spectrometry-based proteomic analysis and subsequent bioinformatic prediction to explore the utilization of BSG as a raw material for the production of protein-based emulsifying ingredients. Forty-eight peptides were selected based on EmulsiPred score, amino acid sequence, and protein abundance for evaluation. All peptides effectively reduced the interfacial tension between oil–water, but only 15 could produce and stabilize emulsions with droplet sizes below 5 µm. Some peptides were able to produce stable emulsions with sub-micron droplet sizes, implying very promising emulsifying properties. This study demonstrated promising emulsifying properties of BSG peptides and suggested that the functionality could be predicted using bioinformatic tools. However, the used tool needs to be further optimized for higher success rate.