Studies On Osmotic Dehydration And Explosion Puffing Drying Of Mango

China is one of the largest mango-producing countries in the world. However, the further-processing proportion of mango is very limited and postharvest loss is extremely serious. Osmotic dehydration has been widely used as a pretreatment for fruits and vegetables before further processing. Combined with other drying technology, it can improve the product quality. As a method of drying, the explosion puffing drying for fruits and vegetables is a new technology, which combines the advantages of hot-air drying and vacuum freeze drying. The puffed products have excellent qualities and have a broad consumer market. So, the research was conducted to osmotic dehydration and explosion puffing drying of mango, and new puffed mango chips were developed. Main research contents and results were as follows:1. The effects of different concentration of sucrose solution and high fructose corn syrup on osmotic dehydration of mango were studied. It was found that water loss, weight reduce, volume reduce and water diffusivity of mango increased with the increase in syrup concentration(45%-65%). However, solid gain and solid diffusivity of mango were lower in high concentration of syrup solution. The water diffusivity and solid diffusivity of mango were respectively3.20min-1/2,0.35min-1/2in65%high fructose corn syrup.2. The effects of vacuum, pulsed vacuum and ultrasound on osmotic dehydration of mango were studied. Compared to the control treatment, vacuum, pulsed vacuum and ultrasound enhanced water and solid diffusion, and the greatest water diffusivity(3.37min-1/2) occurred under ultrasonic treatment, while the largest solid diffusivity(0.46min-1/2) was achieved under vacuum condition. Moreover, the dehydration efficiencies of mango were lower under vacuum, pulsed vacuum and ultrasound treatments.3. The effects of different concentration of pectin on osmotic dehydration of mango were studied. Added pectin into the osmotic solution, water loss, solid gain, water diffusivity and solid diffusivity of mango decreased as the pectin content increased(0-5%). The water diffusivity and solid diffusivity of mango were respectively3.56min-1/2,0.23min-1/2in osmotic solution added2.5%pectin. Moreover, the pectin improved the dehydration efficiency of mango, and the higher the pectin content was, the better the result.4. The effects of osmotic pretreatment and puffing water content on quality of mango chips by explosion puffing drying were investigated. Compared to non-osmotically pretreated products, osmotically pretreated samples had bright color, high hardness and crispness values, and low expansion ratio and rehydration ratio values. According to the sensory evaluation results, all the puffed chips had good quality and were considered acceptable. No significant influence was found for the puffing water content on quality of mango chips. But comparatively, the puffing water content of30%was more appropriate for processing mango chips. These samples had better quality on color, expansion, rehydration and so on.