为研究微波辅助热风干燥预处理对油炸紫薯片品质的影响,以厚度为3 mm的新鲜紫薯片为对象,首先采用不同微波功率(259、280、358 W)辅助热风(50、60、70℃)干燥方式对紫薯片进行预干燥,对不同微波功率(259、280、358 W)干燥后的紫薯片油炸8、3.5、2.5 min,研究紫薯片预处理过程的干燥特性及花青素含量,以及油炸紫薯片产品的色泽、脆度、硬度和脂肪含量等。结果表明:随着微波预处理功率的升高,紫薯片达到干燥终点的时间缩短(90 min以上),平均干燥速率显著提高;并且热风干燥温度越高,微波预处理对干燥效率的促进作用也越明显。而低功率(259 W)的微波辅助50℃热风干燥联用更有利于干燥紫薯片花青素的留存;较低功率(259、289 W)的微波预处理不仅在保护产品颜色上具有优势,还可以使得油炸紫薯片更高的硬度和更好的脆性。在不同微波预处理功率下,油炸紫薯片的脂肪含量最低值基本一致。本研究可为微波辅助热风技术在干燥紫薯及其他农产品干燥中的应用提供参考。
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.
Science and Technology of Food Industry
purple potato chips
hot air drying