Valorization of red dragon fruit peel (Hylocereus polyrhizus) as a functional ingredient for fortified biscuits: physicochemical, nutritional, and sensory implications

This study valorizes red dragon fruit peel (an agro-industrial byproduct) as a useful ingredient in biscuits. Proximate analysis of the Red dragon fruit peel powder (RDFPP) revealed a high crude fiber (23.68%), ash (10.60%), and carbohydrates (43.32%), along with bioactive components such as total phenolic content (0.34 mg GAE/g), flavonoids (53.32 mg QE/g) and antioxidant activity: 43.22%). Fourier transform infrared spectroscopy identified functional groups associated with polysaccharides, phenolic content, flavonoids, and lipids in both peel and biscuits. Biscuits containing 0-9% RDFPP were evaluated for physicochemical, bioactive, sensory, and microbiological qualities. Increasing RDFPP substitution increased ash (0.71% to 2.27%) and fiber (0.08% to 0.74%), while decreasing moisture (5.58% to 4.21%) and pH (5.34 to 5.03), enhancing shelf stability. Antioxidant activity and…