Physicochemical properties, the digestible and resistant starch content of chestnut flour with different particle sizes

Abstract

In this study, chestnuts were processed into flour, and the obtained chestnut flour (CF) was passed through a sieve with an aperture size of 212 µm. Then the physicochemical properties, digestible and resistant starch contents of CF1 (<212 µm), CF2 (≥212 µm), and commercial chestnut flour (CCF) were determined. It was found that CCF had the highest values in terms of proximate composition, total soluble polyphenol content (891.25 mg GAE/100 g), and antioxidant activity (ABTS: 1552.11 mg TE/100 g, DPPH: 2003.01 mg TE/100 g). On the other hand, CF1 was superior in terms of resistant starch content (39.31 g/100 g, dw) (p < 0.05). The resistant starch content of CF1 was approximately 1.5-fold and 3-fold higher than CCF and CF2, respectively. Furthermore, the rapidly digestible starch content of CF1 (2.1 g/100 g, dw) and CF2 (0.93 g/100 g, dw) was quite lower than CCF (12.64 g/100 g, dw) (p < 0.05). Moreover, CF1 exhibited lower (p < 0.05) water, alkaline water, and sodium carbonate retention capacities, which make it a potential good flour for cookie and cracker production. In contrast, CF2 could be evaluated as a good ingredient for noodle-type foods due to its lower water solubility index. Considering the least gelation concentrations of samples, it was seen that CF1 (% 10) could also be valorized as a thickening or gelation agent in the food industry, as well as CCF (% 6).