Article info.

ABSTRACT

Received 14 Jan 2019
Revised 01 Jun 2019

Accepted 30 Jul 2019

The difference in growing conditions, cultivating techniques or genotypes resulted in various quality of purple sweet potatoes. The objective of this study was to determine chemical compositions, bioactive compounds (total anthocyanin, phenolic and flavonoid contents) and physicochemical properties (swelling and water solubility indexes, and pasting properties) of flours prepared from purple sweet potatoes grown at five villages in Dong Thap and Vinh Long provinces. In term of dry basis, the chemical compositions of different purple sweet potato flours consisted of 1.08-3.09% of protein, 0.17-0.41% of lipid, 2.49-2.78% of ash, and 93.94-95.92% of total carbohydrate. Purple sweet potatoes grown at Phu Long village (Chau Thanh district, Dong Thap province) had the highest total anthocyanin content (6.8 mg cyanidin-3-glucoside/100 g flour), total phenolic content (202.2 mg FAE/100 g flour), total flavonoid content (85.6 mg RE/100 g flour) and water solubility index (13.6%) as compared to other purple sweet potato flours. Nevertheless, the paste of purple sweet potato from Hoa Tan village (Chau Thanh district, Dong Thap province) had the highest swelling index (7.5 g water/g flour) and manifested the greatest resistance against retrogradation, gel consistency and hot paste stability among other flours. The results of this study provided the useful information about the quality of purple sweet potatoes grown at different locations.

Keywords

Anthocyanin, flavonoid, phenolic, physicochemical properties, purple sweet potato flour

Cited as: Phuong, L.T.K., Tien, N.N.T., Khoa, N.L.A. and Hung, P.V., 2019. Chemical compositions, bioactive compounds, and physicochemical properties of different purple sweet potato flours. Can Tho University Journal of Science. 11(2): 31-37.