Study on coupled hot air and microwave drying of fresh jujube

For drying of fruits and vegetables in high speed,quality and low energy,the coupled hot air and microwave dryer was designed,and drying was conducted with fresh jujubes as test materials.Microwave power,hot air temperatures and surface load were chosen as three factors for analysis drying process.Range analysis was used to discuss the influnce of factors on drying speed,VC content and rehydration rate.The experimental results showed that each factor to both drying rate and dry product quality had obvious influence.Microwave power had the most important effect,surface load followed,and the hot air temperature had the least effect on drying indexes.Therefore,compared microwave drying and hot air drying,coupled hot air and microwave drying could improve drying speed greatly.Good quality products with high VC content and rehydration rate could be also gained.