Valorizing Food Waste (Banana Peel) Into an Edible Product: A Study on the Effect of Banana Peel Flour on the Physicochemical, Antioxidant, Textural, and Sensory Properties of Cookies

This study investigated the impact of banana peel flour (BPF) incorporation on cookies' nutritional, functional, physical, and antioxidant properties. Refined wheat flour was partially substituted with BPF at levels of 5% (BPF1), 10% (BPF2), 15% (BPF3), and 20% (BPF4), with a control sample (BPF0) containing no BPF. The inclusion of BPF resulted in significant ( p < 0.05) changes in the proximate composition of the cookies. Moisture and ash contents increased from 3.60 to 5.90 g/100 g and 1.20 to 1.88 g/100 g, respectively, whereas protein and crude fat contents decreased from 8.23 to 5.38 g/100 g and 22.18 to 17.09 g/100 g, respectively. The BPF4 sample showed the highest moisture and ash contents, whereas the control (BPF0) exhibited higher protein and fat levels. Physical characteristics were also significantly ( p < 0.05 ) affected, with cookie weight ranging from 10.51 to 15.47 g, diameter ranging from 4.99 to 5.02 cm, thickness ranging from 0.62 to 0.94 cm, and spread ratio ranging from 5.30 to 8.09. A progressive increase in hardness was observed with BPF inclusion, ranging from 5.952 to 15.910 N. Water absorption capacity (WAC) and oil absorption capacity (OAC) increased from 58.71% to 81.20% and from 70.20% to 84.73%, respectively, from sample BPF0 to BPF4. Color measurement values (L*, a*, b*) decreased with higher BPF levels, indicating darker and less saturated cookies. Antioxidant properties improved significantly ( p < 0.05 ) with increasing BPF content, with total phenolic content increasing from 0.351 to 0.986 mg GAE/g and DPPH radical scavenging activity increasing from 49.81% to 74.18%. Despite these changes, sensory evaluation showed no significant differences between the control and enriched cookies, confirming the acceptability of BPF as a functional ingredient in baked products.