Optimizing Probiotic Low‐Fat Yogurt: The Benefits of Incorporating Defatted Rice Bran for Enhanced Quality and Functionality

This study investigated the effects of incorporating defatted rice bran (DRB) at different concentrations (0.5%, 1%, 1.5%, and 2%) on the quality, microbiological, and sensory characteristics of probiotic low-fat yogurt (LFY) during a 21-day storage period at 4°C. DRB is rich in dietary fiber, essential amino acids, vitamins, and bioactive compounds, and its addition aimed to enhance the nutritional and functional properties of LFY. LFY samples were evaluated for proximate composition, hardness, viscosity, syneresis, color characteristics, rheology, and sensory evaluation. Also, microbiological analysis includes total bacterial counts (TBC), <i>Lactobacillus delbrueckii</i> <i>ssp.</i> <i>bulgaricus</i>, <i>Streptococcus thermophilus</i>, <i>Bifidobacterium bifidum</i> counts. Results indicated that DRB addition significantly (<i>p</i> < 0.05) increased probiotic counts, especially at 1% and 1.5% concentrations, with these samples maintaining higher bacterial stability over the storage period. DRB-added LFY also showed improved nutritional profiles, with increased TS, protein, ash, fiber, and antioxidant activity. Additionally, hardness, viscosity, and rheology (G' and G″) values significantly (<i>p</i> < 0.05) increased with the addition of DRB, while syneresis significantly (<i>p</i> < 0.05) decreased. However, higher DRB concentrations negatively affected the color, with lightness decreasing and the browning index increasing. This also impacted sensory characteristics, resulting in lower scores for color, flavor, and overall acceptability, particularly in LFY with 2% DRB. To conclude, moderate DRB addition (up to 1.5%) optimally balances the enhancement of probiotic and nutritional properties with acceptable sensory quality offering a viable strategy for producing functional low-fat yogurt.