板栗褐变控制及干燥条件的优化

Browning control of chestnut and optimum of drying conditions

为了控制板栗褐变,确定其最佳干燥工艺,在干燥前采用蒸煮灭酶处理和抗褐变剂处理后,通过控制干燥温度和时间,以感官指标和水分含量来确定板栗最佳干燥工艺。试验结果表明,蒸煮温度100℃、蒸煮时间8 min能有效杀灭多酚氧化酶(PPO)的活性;柠檬酸、抗坏血酸、EDTA-2Na 3种抗褐变剂对板栗褐变都有抑制作用,且三者按照8∶1∶0.4(质量比)联合控制褐变效果最佳,抑制率可达91.2%;在热风干燥过程中最佳干燥条件为干燥温度70℃,时间180 min,此时水分含量达到9.1%,感官品质最好。

In order tocontrol the chestnut browningand choose the optimal dryingconditions, the activityof PPO were restrained by cooking and anti-browning reagents（citric acid、ascorbic acid、EDTA-2Na） were choosed to treat chestnut. During chestnut drying, the optimal drying conditions, namely, drying temperatures and times were choosed based on the index of sensory quality and contents of chestnut. The results showed that activity of PPO in chestnut was killed effectively at 100 ℃ for 8 min during cooking. The quality ratio of citric acid,ascorbic acid and EDTA-2Na was 8∶1∶0.4,which was the optimal ratio to control chestnut browning. In this condition,the restraining rate of browning was 91.2%. In the hot air drying process, the best drying conditions were at the drying temperature 70 ℃ and drying time 180 minutes, which can sustain the best sensory quality and control the moisture content below9.1% of chestnut.