Experimental Study On Joint Drying Characteristics And Quality Of Jujube Tablets

Jujube has a long history of planting and has a strong blood and beauty effect.The planting area of ?jujube trees in southern Xinjiang has increased year by year.Because of the large moisture content of fresh jujube wet base,it is prone to rot and mildew.At present,most of the jujube drying methods have high drying cost,long drying time and great loss to the quality of jujube.In order to promote the healthy development of jujube drying industry,this paper takes Xinjiang gray jujube tablets as the research object.Firstly,the single hot air drying method is studied to obtain the best jujube slice thickness and hot air drying temperature.The drying method of this experiment is hot air drying.The foundation is combined with other single drying methods,and the quality of the dried jujube tablets is taken as an index to obtain an optimal combined drying method.The hot surface-vacuum combined drying method is studied by response surface analysis method,and the process is optimized to find the drying.The optimal process parameters of the method provide theoretical support for the improvement of the processing technology of the jujube.(1)Study the changes of water content,rehydration ratio,color difference and texture characteristics of ash jujube tablets at different drying temperatures(55 ° C,60 ° C and 65 ° C)and different section thicknesses(3 mm,4 mm and 5 mm).The results show that when the hot air drying temperature is 60 ° C and the jujube slice thickness is 3 mm,the drying rate is relatively fast,the rehydration is good,the color difference is good,and the mouthfeel is good.(2)Based on hot air drying at 60 °C(thickness of jujube sample: 3mm),combined with other single drying methods,the moisture content change,sensory evaluation,texture structure microstructure and rehydration ratio are used as indicators to find the most Good joint drying process.Experiments show that hot air-microwave combined drying can obtain the fastest drying rate;however,when the quality of jujube tablets is studied by rehydration ratio,texture characteristics,sensory evaluation and microstructure,the hot air-vacuum combined dry jujube tablets is obtained.Dry quality.(3)Single factor test was carried out on hot air-vacuum combined drying to determine the significant influence of the thickness of the jujube,drying time and drying temperature on the whole experiment.According to the Box-Benhnken Center combined test design principle,based on the response surface analysis method,the drying temperature,the thickness of the jujube and the drying time were used as the independent variables,and the color difference,rehydration and elasticity were used as the detection indexes to analyze the hot air-vacuum combined drying.Data processing,obtaining the multiple regression quadratic equation under the drying mode,referring to the weighted scoring method,comprehensively evaluating the regression equation of the index Z by analysis of variance,and determining the coefficient R2=0.92 indicates that the variance is significant.The process parameters of hot air-vacuum combined drying best jujube tablets were obtained by response surface test interaction factor analysis: jujube slice thickness: 3mm,hot air drying temperature:60 ° C,vacuum drying temperature58.78 ° C,vacuum degree 75 kpa drying time 5.74 h(hot air drying for 3 h,vacuum drying for 2.74 h).The jujube tablets dried under this drying process have good rehydration,good color difference and elasticity.