Effect of Microwave-assisted Hot Air drying Pretreatment on Quality of Fried Purple Potato Chips

The research focused on the influence of microwave-assisted hot air drying pretreatment on the quality of deep-fried purple potato chips. Taking the fresh purple potato chips with a thickness of 3 mm as the object,they were pre-dried by different microwave pretreatments(259,280,358 W)and assisted with hot air of different temperatures(50,60,70 ℃). The dried purple potato chips with different microwave power(259,280,358 W)were fried for 8,3.5 and 2.5 min. The drying characteristics in pretreatment process and the quality of fried purple chips,such as color,brittleness,hardness,water loss rate and fat content were detected. The results showed that the increasing of microwave pretreatment power led a decrease in drying time(minimum 90 min)and a significantly increase in average drying rate. Moreover,the higher the hot air drying temperature was,the more obvious the effect of microwave pretreatment on reducing drying efficiency was. On the one hand,the combination of microwave pretreatment with low power(259 W)and hot air drying with low temperature(50 ℃)was more beneficial to the retention of anthocyanin in the product. On the other hand,microwave pretreatment with lower power(259,289W)not only protected product color,but made deep-fried purple potato chips with a higher hardness and better brittleness. The lowest fat content of fried purple potato chips under different microwave pretreatment power were in substantial agreement. This study would provide a reference for the application of microwave assisted hot air technology in drying purple potato and other agricultural products.