Physicochemical, nutritional, phytoconstituents, and antioxidant properties of three different processing techniques of pumpkin (Cucurbita pepo) pulp flour

Abstract

This study investigated the effect of boiling and fermentation on the physicochemical, functional, phytoconstituents, and antioxidant properties of pumpkin (Cucurbita pepo) pulp flour. The fresh pumpkin pulp obtained was divided into three equal portions for making pumpkin flour and subjected to boiling and fermentation, while the third portion was used as uncooked sample. Fermentation was carried out naturally by soaking the pumpkin pulp in 1:3 (w/v) ratio of water at 25 ℃ for 48 h using a traditional method, while boiling was at 100 ℃ for 20 min. The samples were thereafter oven-dried at 60 ℃ and milled into flour. The fermented sample had the lowest pH and the highest protein content, while the boiled sample had the highest fibre content. Boiled and fermented samples had higher Ca, K, and P contents. The total phenol and FRAP increased by boiling and fermentation. However, the fresh pumpkin sample had the highest total flavonoid content and ABTS ability. The fermented sample recorded the highest DPPH radical scavenging ability and the least phytoconstituents. All the flour samples (uncooked, boiled, and fermented) showed reasonable physicochemical and antioxidant properties while fermented samples had the highest nutritional content, antioxidant properties, and the least phytoconstituents.