Abstract:
The growing global concern for sustainable food systems has encouraged the
utilization of agro-industrial by-products and underexploited crops in functional food
development. This study aimed to formulate a nutritious snack bar using superfine string hopper
flour by-product, an underutilized rice-based processing fraction, and horse gram (Macrotyloma
uniflorum) flour, a protein and fiber rich legume. Three flour combinations (50:30:20, 40:40:20,
and 30:50:20 of string hopper by-product, horse gram flour, and wheat flour, respectively) were
prepared and evaluated for nutritional (moisture, protein, fat, fiber, ash, and carbohydrate
content), sensory, and storage characteristics (pH, color, sugar, moisture, microbial quality, and
sensory stability). The formulations were standardized using guar gum (1%) as a binder,
margarine (8%) as a fat source, and date paste (40%) as a natural sweetener. Sensory evaluation
was conducted using a five-point hedonic scale, and data were analyzed using the Friedman test
(95% confidence). The blend containing 40% string hopper by-product, 40% horse gram flour,
and 20% wheat flour achieved the highest acceptability. After optimizing sweetness
enhancement using a date paste-groundnut mixture, 40% date paste incorporation by direct
mixing was the most preferred, while coconut milk improved texture and mouth feel. The
optimized snack bar contained 14.75±0.63% moisture, 8.83±0.26% protein, 6.94 ± 0.07% fat,
3.20 ± 0.55% fiber, 2.85 ± 0.80% ash, and 63.43 ± 1.11% carbohydrates. Shelf-life evaluation
over four weeks showed superior quality retention under refrigeration (4 ± 1 °C), while ambient
samples (28 ± 2 °C) developed mold after 16 days. Overall, the findings reveal the potential of
this flour blend in developing sustainable, nutrient-enriched, and shelf-stable snack foods.
