Effects of processing conditions on anthocyanin compositions and antioxidant capacity of instant purple sweet potato powder

Abstract

The purpose of this project is to investigate the optimal processing conditions to produce an instant purple sweet potato powder with high amount of anthocyanin and antioxidant capacity and to evaluate the sensory qualities of this product. The highest anthocyanin composition was obtained (26.00 ± 0.60 mg anthocyanins/100g powder) under the optimal processing conditions using cutting size of 3cm and drying temperature of 55oC. This also showed a high result on antioxidant activity that is 61.31 ± 2.30%. An instant drink was developed from the powder produced under condition above. A quantitative descriptive analysis method was applied to define the sensory profile of the products and consumer preference test was also performed to predict the acceptability of customer of the product formed by instant sweet potato powder and milk powder ratio of 3:2 was most preferred by panelists. Keywords: Purple sweet potatoes, Ipomoea batatas (L.) Lam., anthocyanin, antioxidant activity, sensory evaluation