The Effect Of Vacuum Microwave Drying On The Dried Quality Of Lycium Barbarum L

In this experiment,vacuum drying technology was used to study the changes of quality components of dried wolfberry under different drying conditions by vacuum drying with "Ningqi No.1"wolfberry in the northern part of Helan Mountain in Ningxia.The results showed that:(1)The effect of different microwave power treatments on the quality of wolfberry:the shape of fresh and dried wolfberry did not change significantly,and the fruitiness of dried fruit was varied and fruit color was different.When the microwave treatment was sufficient,the fruit showed red colour,The total contents of total acid,total sugar,total phenolics,polysaccharides and carotenoids in different microwave power were different,and the contents of total acid,total sugar,total phenol,polysaccharide and carotenoid content at 500?500?400?600 and 200KW were different highest.(2)Effects of different vacuum treatments on the quality of Chinese wolfberry:There was no significant change in the shape and fruit shape of dried wolfberry fruit under different vacuum treatments.When the vacuum degree is 75kPa or more,the dry fruit is the best.Under different vacuum degree,the content of total acid,total sugar,total phenol and carotenoid is increased first and then decreased except polysaccharide gradually rising.The total acid,total sugar,total phenol,polysaccharide and carotenoid was the highest when the vacuum degree was 75,75,75,85 and 65 kPa.(3)Effects of different loading on the quality of wolfberry:the effect of different loading on the fruit traits of dried lycium barbarum L was not significant.The total acid,total sugar and total phenol,Carotenoid content was first increase and then reduce under different loading.When the loading amount is 300,500,400,600 and 400 g,the total acid,total sugar,total phenol,polysaccharide and carotenoid content of lycium barbarum L are the highest.(4)Optimization of the technological conditions of vacuum microwave drying wolfberry:Design-Expert software was used to design the experiment.The polysaccharide was used as the index to optimize the microwave power,vacuum and loading conditions.The drying parameters were as follows:microwave power 500kW,A vacuum of 85 kPa and a load of 450 g.Under these conditions,the actual measured polysaccharide content was 3.12g/kg.(5)different dry way to lycium barbarum L dry fruit hygroscopic characteristics:Different treatment wolfberry fruit dryness significantly showed different effects,vacuum microwave dry wolfberry fruit dryness of the smallest.(6)Effects of different drying methods on the moisture characteristics of Lycium barbarum L:The moisture characteristics of lycium barbarum dried with different drying methods were showed that the moisture rate of each sample is almost continuously decline,and then gradually decline in the downward trend,different dried wolfberry fruit has a certain Moisturizing,and the moisture retention of Lycium barbarum L which use vacuum microwave drying methods is the best.(7)Different treatments of antioxidant activity of Lycium barbarum L extract in vitro:Different samples have a certain ability to clear the DPPH free radicals,the vacuum microwave wolfberry dried fruit water extract is the strongest;the reduction force of the extract of dried fruit water from different treatments increased rapidly with the increase of concentration which had a strong dependence.The chelating activity of water extracts of Lycium barbarum with vacuum microwave treatment was strongest.different treatment of wolfberry dried fruit water extract were markedly different.(8)Different treatments on the volatile compounds characteristics of lycium barbarum L dried fruits:Different treatments of volatile compounds have significant differences,vacuum microwave treatment of the largest number of volatile substances,a total of 57 species;hot air dried wolfberry volatile substances in the least,only 52 species.The different treatments have significant effects on volatile matter content,and the alcohol content of vacuum microwave treatment is the highest.Ester material with Freeze treatment is the highest.The drying of the acids material was higher than that of the others.Aldehydes,ketones and terpenes are very small.Vacuum microwave treatment of wolfberry dried fruit showed the best performance of its volatile compounds.