Tailoring Fermentation with Selected Lactic Acid Bacteria: Starter Design, Technological Performance, and Functional Outcomes in Non-Conventional Food Matrices

The intentional selection of lactic acid bacteria (LAB) strains as functional starters represents a pivotal shift in fermented food design — from empirical fermentation toward precision biotransformation. Among the most promising candidates, LAB isolated from traditional fermented foods (kefir, kombucha, kimchi, sauerkraut), particularly exopolysaccharide (EPS)-producing strains, have demonstrated remarkable technological versatility: modulating texture and viscosity through EPS synthesis, enhancing bioactive metabolite profiles, and conferring immunomodulatory and antimicrobial properties to the fermented matrix. Critically, the performance of these starters is highly strain- and matrix-dependent — a reality that demands systematic evaluation beyond traditional dairy substrates.The growing demand for sustainable, plant-based, and allergen-free fermented foods has expanded the landscape of relevant matrices to include legume and nuts-based substrates, cereal ferments, and tuber-derived products. However, the behavior of selected LAB starters in these non-conventional matrices remains poorly characterized. Key technological parameters — EPS yield, acidification kinetics, proteolytic activity, metabolite production, and probiotic trait stability — are known to shift substantially with the fermentation substrate, yet the mechanistic underpinnings of these shifts are not well understood.This Research Topic aims to bridge the gap between microbial strain selection and product-level functional outcomes in non-conventional fermented food matrices. While considerable research has addressed LAB physiology in dairy systems, the translation of starter design principles to alternative matrices remains fragmented and largely empirical. By focusing on the interplay between starter identity, matrix composition, and process conditions, this collection seeks to generate actionable knowledge for the rational design of fermented functional foods beyond dairy. Contributions that integrate microbiological, physicochemical, and nutritional perspectives — from strain characterization through to product validation — are particularly encouraged, with the ultimate goal of supporting the development of safe, functional, and sustainable fermented products for diverse dietary needs.This Research Topic welcomes Original Research, Review, Mini-Review, Systematic Review, and Perspective articles addressing the following themes:• Strain selection and characterization: screening and functional profiling of LAB isolates from non-conventional sources (kefir, fermented plant matrices, artisanal products) for use as defined starters• EPS production and functionality: structural characterization of LAB-derived exopolysaccharides and their role in texture, water-holding capacity, and bioactivity in plant-based or alternative food matrices• Technological performance in non-conventional matrices: acidification kinetics, proteolytic and lipolytic activity, metabolite profiles, and survival of selected LAB in legume-, cereal-, nut-, or tuber-based substrates• Process parameters and their impact on functional properties: effect of temperature, pH, inoculation level, and fermentation time on EPS yield, probiotic trait expression, and product quality• Safety assessment of novel starter applications: evaluation of antibiotic resistance profiles, absence of virulence factors, and GRAS/QPS status of selected LAB strains in new matrix contexts• Probiotic trait stability across matrices: comparative assessment of GI tolerance, adhesion to intestinal epithelial cells and mucus, and competitive exclusion capacity of LAB starters when applied to non-dairy vs. dairy substrates• Multi-omics approaches to starter performance: metatranscriptomic, proteomic, or metabolomic studies linking gene expression patterns of LAB starters to functional outcomes in the fermented product• Functional food product development: design and validation of novel fermented products using selected LAB starters, with characterization of nutritional, sensory, and bioactive propertiesStudies focused exclusively on LAB in clinical settings without a food matrix component, or on spontaneous fermentation without defined starter intervention, fall outside the scope of this Research Topic. Topic editors: Ana Agustina Bengoa, Elisabeth Neumann, Raquel Mateos Briz Source: https://www.frontiersin.org/research-topics/86400/tailoring-fermentation-with-selected-lactic-acid-bacteria-starter-design-technological-performance-and-functional-outcomes-in-non-conventional-food-matrices