Enhanced Nutritional and Bioactive Properties of Riceberry Rice Amazake Lactic Fermented with Thermotolerant Pediococcus acidilactici FSPO-PJ1

Abstract

Thailand is rich in microbial and crop biodiversity, making it ideal for functional food development. This study used Pediococcus acidilactici FSPO-PJ1, a thermotolerant lactic acid bacteria (LAB) strain isolated from Thai fermented food, to ferment Thai riceberry rice amazake lactic, a functional beverage made from Thai pigmented rice. This strain, isolated from fermented spring onion, was selected for its thermotolerance and evaluated for antagonism against foodborne pathogens (Bacillus cereus and Staphylococcus aureus) to verify its food safety profile. Enhancements of the health-related functional properties of riceberry rice amazake fermented with P. acidilactici FSPO-PJ1, such as nutrition, metabolites and bioactivities, were assessed and compared with those of conventional riceberry rice amazake (RB-AMA). Parallel fermentation of riceberry rice amazake lactic with rice koji and P. acidilactici FSPO-PJ1 at 50 °C (FSPO-PJ1 amazake) yielded significantly higher concentrations of lactic acid, amino acids (histidine, lysine, cysteine, glycine, proline, alanine, leucine and methionine) and vitamin B (B1, B2, B3 and B9) than RB-AMA. FSPO-PJ1 amazake also had significantly higher concentrations of total phenolic compounds (1.274 vs. 1.080 mg GAE/g) and significantly higher antioxidant activity than RB-AMA (0.278 vs. 0.052 mg TE/g). Moreover, FSPO-PJ1 amazake demonstrated anti-inflammatory activity by inhibiting nitric oxide (NO) in lipopolysaccharide-stimulated RAW 264.7 cells; FSPO-PJ1 amazake treatment exhibited significantly higher NO inhibition (46.07%) than treatment with RB-AMA (40.86%) or the NO synthesis inhibitor NG-nitro-l-arginine methyl ester (L-NAME; 40.92%). This study is the first to demonstrate the potential of newly isolated P. acidilactici FSPO-PJ1 in enhancing nutritional and bioactive properties in riceberry rice amazake lactic, providing a novel approach for functional fermented food production.