Shelf-life and consumer acceptance of rice and tiger nut plant-based fermented beverages

The development of innovative fermented beverages from Mediterranean plant materials represents a promising approach to meet growing consumer demand for healthy, sustainable alternatives to dairy products. This study evaluated the shelf life, through microbiological, physicochemical and sensory parameters, and consumer acceptance of fermented plant-based beverages made from rice and tiger nut.

The plant-based beverages were produced with these raw materials followed by controlled fermentation at 37°C using VEGE061 commercial starter until reaching pH 4.0-4.5. Shelf-life studies were conducted over 10 days under refrigerated storage conditions (1/3 at 4°C and 2/3 at 8°C). Consumer acceptance was assessed for fermented rice and tiger nut beverages using a 60-member untrained panel through hedonic scale (1-9 points), Just-About-Right (JAR) analysis, and purchase intention evaluation.

Results demonstrated microbiological safety throughout storage (mesophilic aerobes, molds and yeasts) with high acidolactic bacteria counts (6-7 log CFU/g) and confirmed toxicological safety. pH values decreased slightly during 10-day shelf-life (rice: from 4.05 to 3.82; tiger nut: from 4.24 to 4.12; carob: from 4.35 to 4.19), while water activity remained stable (aw = 0.97-0.98). Phase separation during storage was reversible upon agitation. Consumer testing revealed significant differences in acceptance, with fermented rice-based beverages receiving the highest scores across all sensory attributes. Fermented rice beverages achieved mean acceptance scores of 5.17-5.82, while fermented tiger nut beverages scored 3.30-5.38. Ranking analysis showed 80% consumer preference for fermented rice beverages versus 20% for fermented tiger nut beverages. JAR analysis indicated insufficient sweetness as the primary limiting factor. Purchase intention was notably higher for fermented rice beverages (37% positive) compared to fermented tiger nut drinks (10% positive).

These findings demonstrate the commercial potential of Mediterranean plant-based fermented beverages, particularly rice-based formulations, and the need for sweetness optimization to enhance consumer acceptance and market viability.