METABOLOMIC PROFILING OF PROBIOTIC-FERMENTED PLANT-BASED BEVERAGES USING HPLC AND FTIR SPECTROSCOPY

Abstract

The increasing global demand for vegetarian and natural foods has driven the development of probiotic-fermented plant-based beverages. This study aimed to enhance the nutritional and functional properties of rice milk fortified with date pulp through controlled fermentation using Saccharomyces boulardii. Response Surface Methodology (RSM) with Central Composite Design (CCD) was employed to optimize fermentation conditions including date pulp concentration (1-4 g), inoculum size (2-5 mL), and incubation time (24-96 hours). The optimal fermentation conditions (1 g date pulp, 5 mL inoculum, 96 hours) yielded a pH of 4.52, titratable acidity of 0.45%, and viable cell count of 7.98 log CFU/mL. ANOVA revealed significant model terms (p < 0.05) with strong interactions between variables, particularly AB and AC (p < 0.05). Proximate analysis demonstrated substantial nutritional enhancement following fermentation: crude protein increased from 8.5% to 12.8%, ash content rose from 3.8% to 4.2%, while carbohydrates decreased from 84.5% to 80.2%, indicating active microbial metabolism. HPLC analysis confirmed the production of bioactive metabolites including organic acids and phenolic compounds. FTIR spectroscopy revealed characteristic functional groups including broad O-H/N-H stretching at 3281 cm⁻¹, carbonyl (C=O) groups at 1636 cm⁻¹, and aliphatic C-H stretches at 2927 and 2856 cm⁻¹, confirming structural modifications of macronutrients and enzymatic activity during fermentation. This research validates rice milk supplemented with date pulp as an effective substrate for probiotic fermentation, yielding a functional beverage with enhanced nutritional profile, viable probiotic content, and diverse bioactive metabolites. Future studies may explore additional plant-based substrates and probiotic strains to further optimize product quality.