The aromatic footprint of Lactiplantibacillus plantarum: volatilome intraspecific diversity and variability across food matrices

Background Lactiplantibacillus plantarum is a metabolically versatile lactic acid bacterium widely used in fermented foods. Although its probiotic, biocontrol, and fermentation traits are well documented, knowledge of its volatilome across food matrices remains fragmented. Scope and approach This review synthesises peer-reviewed monoculture fermentation studies on volatile organic compounds produced by L. plantarum across eight food categories: dairy, meat, fish and seafood, fruit juices, vegetables, cereals, agricultural by-products, and plant-based milk alternatives. Volatile profiles were compared by chemical class, individual compound, strain identity, and food matrix to identify conserved metabolic traits, matrix-dependent behaviours, and sources of intraspecific variability. Co-fermentation studies with yeasts and other bacteria were also considered to contextualise the metabolic limits and complementary functions of L. plantarum monocultures. Key findings and conclusions Across matrices, L. plantarum consistently generated pyruvate-derived metabolites, with acetoin and acetic acid emerging as recurrent markers of fermentative activity. Aldehyde behaviour was matrix dependent, increasing in dairy, meat, and cereals but decreasing in fruit juices and plant-based milks, where they are often associated with off-flavours. Three recurring patterns emerged: strain-dependent variability in 2,3-butanediol production, strain-specific rather than constitutive acetaldehyde synthesis, and time-dependent ester accumulation. Volatile performance depended strongly on strain–matrix interactions; cross-niche inoculation often enhanced aroma complexity, whereas performance in one substrate did not predict outcomes in another. Co-fermentation expanded volatile diversity, particularly by promoting ester formation and reducing sulphur-related off-odours. Overall, this review supports a strain- and matrix-specific framework for rational flavour-by-design fermentation