Optimization of fermentation process and characterization of non-alcoholic functional beverage from pigmented rice varieties

Traditional foods have recently gained importance because of their role in the United Nations' sustainable development goals (SDG), ensuring health benefits and economic development. Fermented rice water (FRW) is a popular traditional drink among low socio-economic groups, especially in Southeast Asia. This study focused on optimizing fermentation conditions for sustainable food production and consumption of FRW using pigmented rice, followed by analyzing the nutritional, physicochemical and phytochemical properties. Fermenting cooked rice in water for 16 h at 37°C produced bubbles, mild sourness and zero alcohol content. Flavors and sugar were added to optimized FRW as food additives to enhance palatability. Nutritional profiling showed that black FFRW had the highest protein (0.06%), carbohydrate (13.25 g/100 mL) and calorific value (78.09 kcal/100 mL). However, brown FFRW had the highest vitamin B3 (3.12 mg/L) and mineral content. Phenolic and antioxidant activity was highest in black FFRW, followed by red and brown, with maximum bio-accessibility of polyphenols found in black FFRW (75.25%). All FFRW were microbiologically safe and stable during a storage period of 30 days at 4°C. All FRW had >8 log CFU count, with black FFRW having the highest LAB count, indicating their possible probiotic potential in addressing malnutrition and undernourishment. Thus, FFRW holds the potential to be commercialized in the food and beverage sector due to its rich nutritional and functional properties. Furthermore, the consumption of FFRW will preserve traditional knowledge, ensure sustainable livelihoods and contribute to achieving development goals.