Freeze drying of purple sweet potato

Abstract

The purpose of this research is to find a new way to process purple sweet potato to promote purple sweet potato as a delicious and healthy food. Freeze dried purple sweet potato are in best condition in term of moisture and anthocyanin content when being processed as: Freezing temperature: -60˚C; Drying temperature 15˚C; and Drying time 6 hour. Secondly, the pre – freeze drying process also plays an important role in the final quality of product. Best heat treatment to maintain the anthocyanin content and cook the purple sweet potato is steaming pieces of sweet potato for 4 minutes. The survey for perceptive evaluation shows that the consumers accept the new product, and as it is valuable in nutrient content and in diet friendliness, it has a promising market.