Nutritional Evaluation, Antioxidant Potential and Probiotic Stability in Millet-Soy-Based Snack Bars

Abstract

This study investigated the nutritional composition, antioxidant activity, and probiotic viability of millet–soybean-based snack bars enriched with Lactobacillus acidophilus. Snack bars were formulated using millet, soybean, dates, cashew nuts, and date syrup, with probiotics encapsulated in tempered chocolate. Proximate analysis showed that the probiotic snack bar (PSB) contained the highest protein (22.05±0.37 %), fat (12.23±0.38 %), and fibre (12.63 ±0.97 %) contents, alongside reduced carbohydrate levels (38.96±0.54%) compared to millet–soy (MSB) and oat-based control (OSB) bars. Energy values ranged between 343.64±1.91 and 354.05±0.61 kcal/100 g, with PSB recording the highest. Total phenolic content was significantly higher in PSB (24.99±0.41 mg/100 g), accompanied by enhanced antioxidant activity (DPPH: 92.66%; ABTS: 79.54%). A strong positive correlation was observed between phenolic content and antioxidant activity. Viability tests revealed that L. acidophilus in PSB maintained counts above 10⁶ CFU/g at production but declined significantly after five days of refrigerated storage. These results indicate that probiotic millet–soy snack bars are nutrient-dense functional foods with potential antioxidant benefits, though probiotic viability requires optimization for extended shelf life.