Li_2027_Food.Microbiol_142_105304

Fourth-harvest Porphyra haitanensis (FPH) is abundant but underutilized because of undesirable flavor and poor palatability. Microbial fermentation is an effective strategy for the high-value utilization of FPH. The metabolic basis and application potential of bioactive compounds accumulated during FPH fermentation by Lactiplantibacillus plantarum and associated with in vitro lipid digestion and absorption inhibitory activities were investigated. The results demonstrated that fermentation increased the maximal inhibition rates of pancreatic lipase, cholesterol esterase, and cholesterol micellar solubility to 68.27 +/- 0.81%, 68.97 +/- 0.61%, and 72.72 +/- 0.52%, respectively, and increased glycocholate and taurocholate binding to 53.79 +/- 0.74% and 55.91 +/- 1.45%, respectively. Metabolomics showed extensive metabolic remodeling and suggested gamma-aminobutyric acid (GABA) and p-coumaric acid (pCA) as putative candidate metabolites associated with the enhanced in vitro lipid-lowering-related activities and flavor quality. KEGG analysis indicated that the accumulation of GABA and pCA may be related to glutamate metabolism, substrate degradation, and associated enzyme-catalyzed pathways, providing a potential metabolic explanation rather than direct evidence of biosynthetic mechanisms. A fermented FPH beverage was subsequently formulated, and the optimal formulation consisted of 70% fermented liquor, 10 g/100 mL erythritol, and 0.5 g/100 mL sodium citrate. The formulated beverage was further subjected to pasteurization, and 90 degreesC for 10 min was selected as the final processing condition for the subsequent storage evaluation. This treatment maintained a high level of in vitro lipid-lowering-related activity, with a pancreatic lipase inhibition rate of 93.02 +/- 1.75%, while providing better physical stability. The shelf life was predicted to be 46 days at 20 degreesC and 308 days at 4 degreesC based on the storage stability model. This study provides a theoretical basis and technical support for the high-value utilization of low-quality seaweed.