Fermentation processes in foods often lead to changes in nutritional and biochemical quality relative to the starting ingredients. Fermented foods comprise very complex ecosystems consisting of enzymes from raw ingredients that interact with the fermenting microorganisms’ metabolic activities. Fermenting microorganisms provide a unique approach towards food stability via physical and biochemical changes in fermented foods. These fermented foods can benefit consumers compared to simple foods in terms of antioxidants, production of peptides, organoleptic and probiotic properties, and antimicrobial activity. It also helps in the levels of anti-nutrients and toxins level. The quality and quantity of microbial communities in fermented foods vary based on the manufacturing process and storage conditions/durability. This review contributes to current research on biochemical changes during the fermentation of foods. The focus will be on the changes in the biochemical compounds that determine the characteristics of final fermented food products from original food resources.

Glycerol-3-phosphate (G3P) is an important component of carbohydrate and lipid metabolic processes. In this article, we provide evidence that G3P levels in plants are associated with defense to a hemibiotrophic fungal pathogen Colletotrichum higginsianum. Inoculation of Arabidopsis (Arabidopsis thaliana) with C. higginsianum was correlated with an increase in G3P levels and a concomitant decrease in glycerol levels in the host. Plants impaired in utilization of plastidial G3P (act1) accumulated elevated levels of pathogen-induced G3P and displayed enhanced resistance. Furthermore, overexpression of the host GLY1 gene, which encodes a G3P dehydrogenase (G3Pdh), conferred enhanced resistance. In contrast, the gly1 mutant accumulated reduced levels of G3P after pathogen inoculation and showed enhanced susceptibility to C. higginsianum. Unlike gly1, a mutation in a cytosolic isoform of G3Pdh did not alter basal resistance to C. higginsianum. Furthermore, act1 gly1 double-mutant plants were as susceptible as the gly1 plants. Increased resistance or susceptibility of act1 and gly1 plants to C. higginsianum, respectively, was not due to effects of these mutations on salicylic acid-or ethylene-mediated defense pathways. The act1 mutation restored a wild-type-like response in camalexin-deficient pad3 plants, which were hypersusceptible to C. higginsianum. These data suggest that G3P-associated resistance to C. higginsianum occurs independently or downstream of the camalexin pathway. Together, these results suggest a novel and specific link between G3P metabolism and plant defense.