pH in the purple sweet potatoes that were undergone for osmotic process are shown in Figure 3. pH of purple sweet potatoes decreased in the samples during storage at both temperature (RT & 4˚C). The highest level of pH (6.72) was found in the potatoes samples. The lowest level of pH at room temperature storage (4.31) and lowest level of 4˚C (6.15). pH of osmotically dehydrated purple sweet potatoes during storage was significantly differed under different temperature storage.
The samples storage at room temperature was losing a_w more quickly when compared with 4˚C.