Reduced-Calorie Apricot-Based Lacto-Fermented Beverages: Evaluation of Probiotic Content, Physicochemical, and...

Optimizing the formulation is essential to enhance probiotic viability, sensory quality, and shelf-life stability, thereby supporting the development of a consumer-acceptable and commercially viable non-dairy functional beverage. This study focused on optimizing the fermentation process of apricot-based beverages using three probiotic strains: Lactiplantibacillus plantarum XL963 (LP), Limosilactobacillus fermentum W8 (LF), and Lactiplantibacillus pentosus ML104 (LPN). Fermentation conditions were optimized by varying sugar content (9-15%) and fermentation temperatures (20°C, 28.5°C, and 37°C) to maximize sensory properties, lactic acid bacteria (LAB) counts, and probiotic viability over 60 days of storage. Following fermentation optimization, beverages with a calorie reduction exceeding 30% were identified, and their physicochemical properties were evaluated throughout the refrigerated storage period for 60 days. LAB counts increased up to 5-6 log units (11.39 ± 0.85-14.69 ± 0.40 colony-forming units (CFU)/mL) during fermentation, rising from initial levels (9.04 ± 0.36-9.08 ± 0.84 log CFU/mL). Throughout the 10-day storage period, viable LAB populations were maintained above the critical threshold of 10⁶ CFU/mL, with counts ranging from 9.13 ± 0.05 to 13.80 ± 0.06 log CFU/mL during storage, as determined by the spread plate method. Calorie reductions ranged from 24.48% to 59.49%, depending on fermentation temperature, sugar content, and the probiotic strain used. The overall sensory acceptability scores of the LF, LP, and LPN samples-fermented under varying sugar concentrations (9-15%) and fermentation temperatures (20°C, 28.5°C, and 37°C)-ranged between 3.34 and 7.60, based on the average values obtained immediately after fermentation and following 10 days of refrigerated storage. Significant changes (p < 0.05) were observed in physicochemical properties, with soluble solids content between 20.73 ± 0.17 and 23.87 ± 0.06, pH values from 3.88 ± 0.01 to 4.28 ± 0.01, and dry matter content between 22.45 ± 0.02% and 26.01 ± 0.37%. Turbidity values ranged from 0.057 ± 0.002 to 0.176 ± 0.0012, while L*, a*, and b* values ranged from 28.45 ± 0.08 to 34.12 ± 0.56, 1.06 ± 0.04 to 3.43 ± 0.16, and 11.36 ± 0.16 to 18.47 ± 0.24, respectively. The color difference (ΔE*) ranged from 0.22 to 16.98, with the highest values observed at the beginning of storage. During the 60-day storage period, apricot beverages containing 12% added sugar and fermented with LF, LP, LPN, and the mix culture (LF + LP + LPN) maintained favorable sensory scores, with values ranging between 6.27 ± 0.82 and 7.18 ± 1.17 for taste, 5.85 ± 0.80 and 7.09 ± 0.60 for color and appearance, 5.82 ± 0.80 and 7.00 ± 0.77 for texture, 6.00 ± 0.83 and 7.00 ± 0.70 for smell, and 6.00 ± 0.65 and 7.00 ± 1.00 for overall acceptability. In conclusion, this study successfully developed reduced-calorie, probiotic-rich, and sensorially acceptable apricot-based beverages, providing a promising functional drink for consumers.