Influence of bitter gourd (Momordica charantia L.) seed powder on physicochemical, phytochemical, and sensory properties of biscuits

Bitter gourd (Momordica charantia L.) seeds are usually thrown away as agro waste even though these are good source of protein, fiber, minerals as well as bioactive compounds with antioxidant activity. Utilization of these valuable waste materials in traditional food systems could create sustainable innovation, meeting UN Sustainable Development Goals (SDG 2, SDG 3 and SDG 12). The present study investigated the effect of incorporation of bitter gourd seed powder (BGSP) on the physicochemical, functional, antioxidant and sensory values, and storage stability of wheat-based traditional biscuits. BGSP was added at the 0% (control), 5, 10, 15 and 20% (w/w) by substituting refined wheat flour. Proximate analysis revealed that protein, crude fiber, ash, and fat content significantly (p < 0.05) rose with an increase in BGSP, however carbohydrate content decreased. Physical tests revealed that the spread ratio, thickness, and diameter decreased as the level of BGSP increased. Functional analysis showed that the total phenolic (TP) content (0.218–1.244 mg/g GAE), total flavonoid (TF) content (0.109–0.699 mg/g CE) and antioxidant activity (DPPH activity 0.099–0.265 µmol/g TE) significantly increased with the addition of BGSP. Sensory analysis (n = 30 panelists, 9-point hedonic scale) indicated that the incorporation of biscuits with up to 5% BGSP was well accepted with similar score of appearance, color, texture, and taste, to control, whereas 10% and 15% incorporation levels scored significantly less, based on increased bitterness and dark color. Comprehensively, the findings indicated that the incorporation of the BGSP up to 20% enhances the nutritional value and functionality of biscuits. The findings highlighted the potential to raise bitter gourd seeds as a cheap and viable food ingredient in the bakery sector.