| The planting area and output of kiwifruit in my country are the largest in the world,and it is increasing year by year.Due to geographical and seasonal restrictions,about40%of kiwifruit is lost every year after being picked.With the increasing popularity of dried fruits by domestic and foreign consumers,this has put forward higher and higher requirements for drying technology.At present,the drying of kiwifruit is plagued by problems such as difficult processing,poor quality and high energy consumption.Therefore,this article optimizes the drying methods and drying parameters to obtain better drying methods and drying parameters.In order to improve the taste and color of kiwi fruit slices and shorten the drying time,the kiwi fruit slices were dried using fluidized bed drying technology,and different hot air temperatures(55,65,75,85°C)and hot air speeds(1.5,2.5,3.5)were studied.,4.5 m/s)and slice thickness(5,10,15 mm)on product quality.1.The sample was dried by a single factor method,and the results showed that the drying process of kiwi fruit slices was mainly characterized by reduced-speed drying,and the effective water diffusion coefficient of each process parameter ranged from1.296 39×10-9?4.589 94×10-9 m2/s;the activation energy is 23.03 k J/mol.A fitting study was conducted on 10 models,and Logarithmic was found to be the best model.2.The quality of dry products was studied by single factor method,and the results showed that too high hot air temperature would cause severe browning and local shrinkage of the sample,hot air speed had no significant effect on the appearance of the sample,and the slice thickness had a significant effect on the appearance;hot air temperature After rising,it will have a significant impact on the microstructure,causing the microstructure lines to become unclear,causing cracks.The hot wind speed has no obvious effect on the microstructure.The slice thickness has a significant influence on the microstructure.The texture pattern becomes unclear,resulting in more cracks.As the temperature of the hot air increases,the hardness of the dry product tends to increase.When the temperature of hot air rises to 85°C,the color and brightness of the sample will decrease.At 65°C,the color difference will be the smallest.With the increase of hot air speed,L gradually increases,and the values of a,b and?E show a gradual downward trend.Dry products The color is gradually improved.As the slice thickness of the test sample increases,the value of L gradually decreases,a,b,and?E first decrease and then rise,indicating that when the slice thickness of the sample is greater than a certain value,it will have a huge impact on the color of the dried sample.3.In order to analyze the influence of each factor on the drying quality,the orthogonal experiment design was used to optimize the hot air convection drying parameters of kiwifruit slices,and the experimental indicators were analyzed through visual analysis and variance analysis.The results showed that each factor has an effect on the drying time.The order of the strength of influence is slice thickness,hot air temperature and hot air speed.The order of the influence of various factors on the rehydration rate is slice thickness,hot air temperature and hot air speed.The order of the influence of each factor on the color difference is hot air temperature,slice thickness and hot air speed.The order of the influence of various factors on hardness is hot air temperature,slice thickness and hot air speed.Temperature has a significant effect on drying time,rehydration rate and color difference.Hot air speed has no significant effect on each test index.Slice thickness has significant effects on drying time,rehydration rate and color difference.When the hot air temperature is 75°C,the hot air speed is 3.5m/s and the slice thickness is 5 mm,the best drying quality is obtained. |
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