Physicochemical and functional properties of sweetpotato flour

BACKGROUND Sweetpotato (Ipomoea batatas Lam.) is a major starchy crop with great agricultural significance in many countries. There is a need to assess more genetic resources for sweetpotato quality improvement. This study aims to analyze physicochemical properties of whole (unpeeled) root flours from seven New Zealand sweetpotato varieties with commercial significance. Using whole unpeeled plants for 'healthy' food formulations becomes more popular due to nutritional effects and environmental concerns. RESULTS Great variations were found in chemical composition, in vitro antioxidant activities, swelling power, water solubility index, in vitro digestibility, thermal, pasting and gel textural properties of the seven flours. The antioxidant activities and phenolic contents were higher in the color-fleshed samples. Correlation analysis showed that the swelling, pasting and texture properties were largely affected by the activity of the endogenous amylase. Principal component analysis was done in four aspects including chemical composition, mineral content, antioxidant activities and functional properties to analyze the similarity and difference among these seven sweetpotato varieties. CONCLUSION The seven sweetpotato flours showed a wide range of functionalities and will be useful for the formulations of diverse and 'healthy' sweetpotato-based products. (c) 2019 Society of Chemical Industry