The Experimental Study Of Carrot Microwave Vacuum Drying Processing Parameters

Carrots are rich in nutrients, has high nutritional value and health effects. Carrots crisp texture, taste better, After a period of storage, they will become soft texture, atrophy, and the color will be brown, small spots will appear on the surface, all of them will affect the taste. Microwave vacuum drying is a new drying technology, which can extend their shelf life, and keep the color, smell, taste and nutrients with the greatest degree. It can dehydrate completely and has good rehydration.In this study, it use fresh carrots as experimental material, and the new microwave vacuum dryer as laboratory equipment, Microwave vacuum drying of carrot trace elements were studied. Through the analysis of microwave vacuum drying process, we can know that the slice thickness, vacuum, microwave power, drying temperature are major factors which can affect the microwave vacuum drying of carrot. By single factor experiments and four factors and five levels of the quadratic regression orthogonal ,we can determine the range of factors. Through the analysis of the mathematical model and the T test variance, we obtained that the impact of factors on the drying time was as follows: microwave power> vacuum> slice thickness. Using SAS software to analysis the results of the second rotation regression of experimental design, then to deal with the parameters. Through them, the optimum conditions we can obtain are as follows: the vacuum is -69.8 kPa, the microwave power is 2 kW the slice thickness is 6.78mm and the drying time is 0.912 h. Meanwhile, in order to further verify the quality of dried carrot, determine a reasonable drying process parameters, the production of different drying methods were compared in this paper. The result is that the products dried by Microwave vacuum are better than hot air drying and microwave drying in the sensory indicators, rehabilitation of water conditions and nutrient content.