Study On Drying Method Of Chinese Wolfberry And Their Drying Solvents

Chinese wolfberry is the fruit with rich sweet and sour taste. It is not only the traditional medicinal matetials, but also a kind of nutritional supplements. Chinese wolfberry has seasonal and regional harvest and short storage period. So drying of Chinese wolfberry becomes one of the important processing. At present,the drying of Chinese wolfberry is mainly traditional natural drying. This method needs long drying time and the mildew rate is high, so it is no guarantee to the quality of the products. It is difficult to meet the needs of the modern production. The drying of coal-fired drying room needs high energy consumption of the drying process and produces pollution severely. The temperature and humidity is not easy to control. The fireworks affects the quality of the dried Chinese wolfberry seriously. The solar drying equipment appears in ningxia region in recent years. It uses of solar energy and electrical energy to dry Chinese wolfberry. It is able to not only save energy and protect environment but also dry fast. The quality of the dried Chinese wolfberry is high using sectional temperature. This paper compared the natural drying, coal-fired drying room and solar drying equipment and studied drying solvents of Chinese wolfberry. This paper provides a certain theoretical and experimental basis for the selection of drying method of Chinese wolfberry and the use of drying solvent. The main research contents and results are as follows:1.The Chinese wolfberry were dried by natural drying, coal-fired drying room and solar drying equipment separately. They were compared the drying rate of Chinese wolfberry by weighing method. Their main functional components were measured and analysed by the variance. The appearance quality and the rate of sugar were measured and analyzed as well. It provides theoretical basis for the selection of drying method of Chinese wolfberry. The fresh Chinese wolfberry were soaked by 5% sodium carbonate solution. Three wire weighing boxes for a group were put in coal-fired drying room, solar drying equipment and the yard of cooperative separately. It was weighed every two hours until reach the standard of drying. The drying time of the three methods were recorded. The test results show that the drying time of the natural air drying is about 78 h and the coal-fired drying room is 34 h. The shortest drying time of the solar drying equipment was about 26 h. The test results show that the main functional components of Chinese wolfberry of the solar drying equipment drying out was highest.It was about 71.77g/100 g. The main functional components of Chinese wolfberry of coal-fired drying room was about 64.59g/100 g. The main functional components of Chinese wolfberry of the natural drying out was lowest.It was about 57.84g/100 g. The Colorimente was used to measure the color of the Dried Chinese wolfberry. The results show that the color and lustre of dried Chinese wolfberry of solar drying equipment was closest to the color and lustre of fresh Chinese wolfberry. The colour and lustre of dried Chinese wolfberry of natural drying was the worst. The lowest syrup yield of dried Chinese wolfberry was the dried Chinese wolfberry using the solar drying equipment. It was about 1.533g/100 g. The highest syrup yield of dried Chinese wolfberry was the dried Chinese wolfberry using the natural drying. It was about 6.739g/100 g.2.The fresh Chinese wolfberry were soaked by eight drying solvents and dried by the solar drying equipment. The drying rate and their main functional components were measured and analysed by the variance. The appearance quality and the rate of sugar were measured and analyzed as well. In the end the best drying solvent was obtained according to that. It is that 80% alcohol and 20% sucrose ester matching into solution, sodium citrate and distilled water match into drying solvent with the weight ratio of 2%, 1% and 97%. The test results show that the shortest drying time with the optimal drying solvent was about 23 h to shorten 3h than using traditional technology. The main functional components of Chinese wolfberry was about 77.41g/100 g more than 5.64g/100 g using traditional technology. The color and lustre of dried Chinese wolfberry with the optimal drying solvent was closest to the color and lustre of fresh Chinese wolfberry. The syrup yield of dried Chinese wolfberry was about 0.702g/100 g to reduce 0.831g/100 g than using traditional technology.3.The best drying solvent was carried out single factor experiment and the response surface using solar drying equipment in terms of time,temperature and the proportion of flux. Finally the using temperature,time and the proportion of flux of the best drying solvent was sure. Certification experiment was done for Chinese wolfberry under these condition. It provided theoretical basis for drying out high quality Chinese wolfberry. The test results show that the using temperature of the best drying solvent was 43℃,time was 10 minutes and the ratio of solution was 0.18. The fresh Chinese wolfberry was soaked by the optimal drying solvent according to this method and then were dried by the solar drying equipment. The drying time was 21 hours with the theoretical prediction. This show that the regression equation can truly reflect the influence of drying time of Chinese wolfberry with the drying solvent.