Infrared based dry blanching and hybrid drying of bitter gourd slices: Process efficiency evaluation

摘要

In the present study, combination of infrared (IR) based dry blanching and hybrid drying involving IR-hot air was used for bitter gourd slices. Infrared blanching conditions were standardized based on the degree of enzyme (peroxidase and polyphenol oxidase) inactivation and product quality. The performance of IR blanching was compared with microwave (MW), water, and steam blanching. The performance of hybrid drying was compared to that of hot air (HA) drying. Microwave and IR blanched slices retained higher amount of ascorbic acid (95% and 93%, respectively) and charantin (76.8% and 74.8%), as compared to water and steam blanching. Infrared blanching followed by hybrid drying required approximate to 66% lesser time than water blanched-HA dried with higher retention of charantin (68.4%), ascorbic acid (86.3%), and chlorophyll (42.9%), also consuming 79% less energy than HA drying. The results showed that IR-based blanching and hybrid drying could be used effectively to produce dried bitter gourd slices having better quality.