Effect of drying methods on physicochemical, antioxidant and functional properties of potato peel flour and quality evaluation of potato peel composite cake

Cakes are usually consumed bakery item all over the world; so, their enrichment with nutrients is an effective way to increase nutrition to the people health. This goal can be achieved using the potato peel flour (PPF) on cake formulation. This research was carried out to compare the effect of drying methods (cabinet and sun drying) on the physicochemical, antioxidant and functional properties of dried potato peel flour (PPF). The physical, textural and sensory characteristics of the PPF incorporated cakes were also evaluated. The PPF was prepared by blanching (at 90–95 °C for 2–3 min), drying (65 °C and 30 °C) and grinding the potato peel; afterwards, the physical and chemical properties of PPF were analyzed. Results showed that cabinet dried PPF contains higher protein (11.39 ± 0.07%), fat (7.23 ± 0.12%), fibre (12.92 ± 0.09%) and carbohydrate content (55.42 ± 1.07%), as well as a lower amount of moisture (7.61 ± 0.01%), and ash (9.63 ± 0.67%) percentage than the sun-dried PPF. Furthermore, the mineral and antioxidant activity was more significant in the cabinet dried PPF compared to sun-dried PPF. Other functional properties such as water and oil absorption capacity, bulk density, foaming capacity, emulsifying activity and swelling capacity were also found to be higher for the cabinet-dried PPF than the sun-dried. Composite cakes were prepared at different ratios of wheat flour to cabinet-dried PPF (100: 0, 96: 4, 94: 6 and 92: 8). The addition of PPF increased the height, volume and weight of cakes compared to the control (100% wheat flour) cakes. In the sensory evaluation, the cakes enriched with 4% PPF achieved the highest score for the sensory attributes. Therefore, the incorporation of 4% cabinet-dried PPF with WF could be suggested for the formulation of composite cakes with better physical and organoleptic qualities.