Effects of Color Protection and Drying Process on the Color of Potato Raw Powder

In this paper, the effects of color protection and drying process on the color of potato raw powder were studied.The effect of sodium D-isoascorbate mass concentration, citric acid mass concentration, calcium chloride mass concentration on the color of potato flour were investigated by single factor and orthogonal experiment to determine the best colorant ratio and concentration.Color of potato raw powder which was produced by different drying methods (hot air flow drying, vacuum freeze drying, oven drying) and at different drying temperatures(hot air flow drying at 40, 60, 80, 100, and 120℃) was determined.The results showed that the best colorant ratio and concentration of the color-protecting agent were 0.5 g/L of sodium D-isoascorbate, 5 g/L of citric acid, and 8 g/L of calcium chloride; the brightness of raw powder produced by hot air flow drying and vacuum freeze-drying was highest; when the hot air flow drying temperature was 60℃, the raw powder was only slightly brownish, and the brightness was the highest.