Author Identifier (ORCID)
Abstract
Brewers’ spent grain (BSG), a protein- and fibre-rich brewing by-product, contains bioactive compounds, yet techniques to fully recover and utilise these bioactive fractions remain underdeveloped. This study investigated the proteolytic transformation of two BSG types, wheat and stout BSG, during 10 days of fermentation with Lactiplantibacillus plantarum . Discovery and targeted LC-MS/MS proteomics were used to characterise the proteome, peptide release, and free amino acid profiles of BSG throughout fermentation. Proteomic analysis identified 503 proteins in wheat BSG and 340 in stout BSG. Wheat BSG generated higher peptide diversity than stout BSG (1,227 vs. 436 peptides, respectively), with peptide release peaking on Day 4, whereas stout BSG showed delayed peptide release, primarily during Days 7–9, indicating substrate-dependent proteolytic dynamics. Targeted quantification of 28 peptides revealed distinct temporal patterns for predicted antimicrobial and antihypertensive activities. Antimicrobial peptides primarily peaked during early-to-mid fermentation in both BSG types, while antihypertensive peptides peaked earlier in wheat BSG and later in stout BSG. Peptides containing partial wheat allergy- and coeliac disease-related epitope motifs were detected predominantly in wheat BSG and accumulated throughout fermentation, whereas such motifs were largely absent in stout BSG. This suggests that intensive thermal processing associated with stout beer production may reduce the prevalence of safety-relevant epitope-containing protein regions. Free amino acid profiling revealed higher conentrations of basic amino acids in wheat BSG These findings demonstrate that BSG type strongly influences proteolytic outcomes and support substrate-specific fermentation strategies for the targeted and safe valorisation of brewing by-products.
Keywords
bioactive peptides, Brewers’ spent grain, food allergen epitopes, Lactiplantibacillus plantarum, peptide profiling
Document Type
Journal Article
Date of Publication
12-1-2026
Article Number
101137
E-ISSN
26668335
Volume
14
Publication Title
Future Foods
Publisher
Elsevier
School
Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science / School of Science
Funding Information
This work has been supported by the Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science (CE200100012), and the Catalyst: Seeding Fund (21-AUT-006-CSG) by Royal Society Te Apārangi, New Zealand.
Funding received from the Australian Research Council (ARC)
CE200100012
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Ha, M. Q., Juhász, A., Santoso, T., Nye-Wood, M. G., Berthevas, M., Zhao, Z., Kitundu, E., Chen, T., Colgrave, M. L., & Le, T. T. (2026). Comparative analysis of amino acid and bioactive peptide profiles during time-resolved fermentation of wheat and stout brewer’s spent grain by Lactiplantibacillus plantarum. Future Foods, 14, 101137. https://doi.org/10.1016/j.fufo.2026.101137