Development and Evaluation of Soy Fiber enriched Functional Cookies by utlization of Okara

Okara, a protein- and fiber-rich byproduct of soybean processing, is often underutilized despite its potential as a valuable food ingredient. Its incorporation into food products offers an opportunity to recover nutrients from food-processing residues, improve resource efficiency, and support the development of value-added, potentially affordable, nutrient-enriched foods. This study aimed to utilize okara flour in the development of soy fiber-enriched cookies and to evaluate its effects on proximate composition, antioxidant activity, physical characteristics, color, and sensory acceptability. Okara obtained from Rawal-1 soybean was dried at 50–60 °C, milled into okara flour, and incorporated into whole wheat flour at substitution levels of 5, 10, 15, and 20%. Five formulations were prepared: T0 (100% wheat flour), T1 (5% okara + 95% wheat flour), T2 (10% okara + 90% wheat flour), T3 (15% okara + 85% wheat flour), and T4 (20% okara + 80% wheat flour). Okara flour contained 19.97 ± 0.09% protein, 17.08 ± 0.08% fat, and 42.02 ± 0.04% crude fiber, demonstrating its nutritional potential as a functional ingredient. Okara incorporation significantly affected the cookies' proximate composition. Ash and crude fiber increased progressively with increasing okara incorporation, while T4 showed the highest moisture (7.25 ± 0.05%), ash (1.08 ± 0.03%), crude protein (7.29 ± 0.17%), crude fat (21.18 ± 0.05%), and crude fiber (1.74 ± 0.04%) contents. Antioxidant activity also increased significantly with okara incorporation, with T4 recording the highest value (54.47 ± 0.28 mg/100 g). Increasing okara incorporation reduced cookie diameter and spread ratio and increased instrumental hardness, while thickness decreased numerically but not significantly. Instrumental color was also significantly affected, with L* decreasing and a* increasing as okara incorporation increased. Sensory evaluation showed that T3 had the highest numerical overall acceptability among the okara-enriched formulations (8.02 ± 0.17), although overall acceptability did not differ significantly among treatments. Overall, T4 demonstrated the greatest nutritional enhancement, whereas T3 represented the most numerically acceptable okara-enriched formulation. These findings demonstrate the potential of okara valorization as a resource-efficient approach for converting a soybean-processing byproduct into value-added, nutrient-enriched cookies. Further research on consumer acceptance and production economics is recommended to establish the feasibility of okara-enriched cookies as potentially affordable nutrient-enriched foods.