Influences of Temperature-Time Blanching on Drying Kinetics and Quality Attributes of Yam Chips（Extracts）

The processing conditions were optimized for the preparation of hot air dried yam chips.The effects of blanching time（0，1，3 and 5 min）and blanching temperature（80 and 90℃）as well as the drying temperature（70，80 and 90℃）on the drying kinetics as well as various quality attributes of yam chips，such as color，texture and brown pigment accumulation and organoleptic evaluation were also investigated.It was found that drying took place entirely in the falling rate period.Longer blanching time and lower drying temperature resulted in better color retention and led to chips of lower browning index.Blanching also reduced the hardness and fracturabilty of the product.The final product showed optimum texture attributes for the blanching treatment of 90℃ for 3 minutes followed by the drying process at 80℃ for 480 minutes.