Hot-Air Drying Characteristics And Mathematical Model Of Cantaloupe Slices

Cantaloupe is a delicious,adequate water and refreshing friut,and has always been known as the“king of melons”.Because of its rich nutrition and high medicinal value,it is favored by consumers.However,due to it's peculiarity of high-sugar and heat-sensitive,the control of drying time and drying quality is always the key technical problem to be solved in the cantaloupe drying process.Therefore,In order to improve the quality of cantaloupe production and shorten the drying period,this article focuses on the hot-air drying kinetics,dried product quality,mathematical model and process optimization of cantaloupe.Firstly,this study use different blanching time(0.5,1.0,1.5,2.0,2.5min),impregnation liquid(0.1%,0.2%,0.3%,0.4%,0.5%citric acid solution)pretreat cantaloupe slices,and then study different hot air temperature(35,45,55,65,75?),air velocities(0.5,1.0,1.5,2.0,2.5m/s),and slice thicknesses(2,4,6,8,10mm)on the hot air drying characteristics and moisture diffusivity coefficient of cantaloupe slices,fited different thin-layer drying mathematical models and the solution method of the applicable models is improved.Finally,combined with the rotation regression orthogonal test,the response surface under the interaction of various drying factors was analyzed,and the most suitable hot-air drying process of the cantaloupe slices was determined.The results show that:0.4%citric acid pretreatment yields the best quality dried product,and slice drying is influenced significantly by temperature and thickness.Moreover,the effective moisture diffusivity coefficients is(4.9080×10^-7?1.1348×10^-7)m²/s,activation energy₍(6)=28.15 k J/mol.Fitting 9 different mathematical models,it is found that the Page model has the highest R² value and the lowest root mean square error RMSE,which is more suitable for evaluating the moisture removal law of hot-air drying of cantaloupe slices.Maintaining the integrity of the internal cells and structure of the material during the drying process of cantaloupe is the key to improving the hydrophilicity and rehydration rate.When the drying temperature is as high as 75°C,the surface hardening of the cantaloupe slices hinder the rehydration of the product,and the Maillard reaction of non-enzymatic browning occurs,resulting in the color of the dried product being dark yellow and black.If cantaloupe slices are too thin,dried products will be fragile.On the contrary,too thick will stick to the teeth and not suitable for chewing.The hot air drying of cantaloupe slices has a significant effect on the b value(yellowness value),and its rehydration rate₍(6)=555.03%.It is found that the interaction between hot air temperature and slice thickness is the most significant by quadratic rotation regression orthogonal test.The hot air temperature of 56?,the hot air speed of 1.6m/s,and the slice thickness of 5.6mm are the best processes for hot air drying of cantaloupe.At this time,the predicted drying time is 178.58min,the rehydration rate is 513.34%,the sensory quality score is 89,the color difference value is 19.9102,and the relative error with the test value is not more than 5%,which further verifies the applicability of the process.