The Research On Explosion Puffing Drying For Mango At Variable Temperature And Pressure Difference

Fresh mangoes were chosen as the test materials which were procured from the localmarket and stored at10℃until used. The explosion puffing drying equipment ofQDPH10-1was used. In this study, The process parameters of the explosion puffing dryingmango had been optimized, and the factors which affected the quality of the mangoproduct were studied, Meanwhile, the changes of the physic-chemical properties, themicrostructure and the flavor substances between flesh mango and puffed mango werecompared and analyzed, and the same comparison and analysis were investigated by fourdifferent drying methods. The suitable drying method of mango was obtained at last,aiming to provide a technical support and theoretical reference for the development ofmango processing industrialization.Through the study of the mango explosion puffing drying, and the comparativeinvestigation on the changes of the physic-chemical properties, the microstructure and theflavor substances of mango products and other three different drying methods, theconclusions can be summarized as follows:1）The appropriate value of the process parameters were obtained by the single factorexperiment, which were slitting thickness was6mm, puffing temperature was80°C,vacuum drying temperature was70°C, vacuum drying time was1.5h, the pressuredifference was0.10MPa, and the dwell time was10min.2）In order to optimize the mango explosion puffing drying technology, a centralcomposite rotatable design (CCRD) was used. The interaction between the threefactors(pre-drying time, puffing temperature, vacuum drying time)and the product qualities(moisture content, hardness, crispness, color and puffing degree) were studied, Theexplosion puffing drying process parameters were optimized by the response surfacemethod and frequency analysis, per-drying time was2.30～2.91h, puffing dryingtemperature was75.10～84.91℃, vacuum drying time was1.10～1.74h.3）Through the comparative study on the changes of the physic-chemical properties,the microstructure and the flavor substances between puffed drying mango and freshmango sample. The results indicated that, explosion puffing drying make the interiorstructure of mango more porosity, the structure was loose, and big bubbles formed Thecontent of protein, beta-carotene and vitamin C was decreased, while the contents of thepotassium in the dried products almost unchanged, and contents of total sugars and totalacids were increased; Compared to the fresh samples, volatile aroma substances ofexplosion puffing mango chips were significantly changed, lose some fragrant componentwhile some special volatile aroma appeared.4）Comparative investigation were carried out to the physic-chemical properties, themicrostructure and the flavor substances of mango chips dried by four different methods(hot air drying, microwave vacuum drying, vacuum freeze drying, explosion puffingdrying at variable temperature and pressure difference). The results indicated that, Vacuumfreeze drying made product nutrient loss less, but crispness not well, hardness was toolarge; The structure characteristics of the hot air drying product were not well, structurecompact, hardness is too large, nearly no crispness, poor taste, the color was bleak and theloss of nutrition was seriously; Microwave vacuum drying products lack crispness, the hardness modest, but color was well, the loss of nutrition was acceptable; The quality ofexplosion puffing drying product were well, especially had good puffing degree, andnutrition loss less, and porous spongiform structure had formed in the chips, and also thebig bubbles were formed.