Research And Application Of Browning Control Technology In Storage Of Dried Grey Jujube

Xinjiang is rich in fruit resources and high in quality.It is one of the main producing areas of dried fruit in my country.Among them,dried red dates are the most sold and characteristic dried fruit.Red dates are prone to quality deterioration during long-term storage,which makes them lose their edible value and cause huge economic losses.Therefore,studying the quality control technology and methods of Xinjiang dried red jujube during the storage period has an important effect on the development of the dried fruit industry.Gray jujube is one of the most popular dried red dates in Xinjiang.In order to improve the storage time and quality of Xinjiang dried grey jujube,and solve the problems of easy browning and easy loss of active ingredients during storage,Xinjiang dried jujube is promoted.Storage and export of grey jujube.In this paper,dried gray dates are used as raw materials to carry out research and application of blanching,color protection,fumigation,packaging and other technical processes,and reduce the quality deterioration of dried grey jujube and control the occurrence of browning during storage.The main findings are as follows:(1)The effect of the combined method of blanching and color-preserving agent on the storage quality of dried grey jujube was studied: Based on the effect of application of 2 kinds of blanching,that is,steaming and hot water,and 5 ways of color protection technologies,like ascorbic acid,L-cysteine,citric acid,chitosan and phytic acid,we screened out the steaming blanching and inhibitors of L-cysteine and phytic acid as the factors of effect,and ratio of the brown stain inhibitors on peel and pulp as response values,and made response surface analysis by establishing regression equation model with optimal design through Box-Behnken method.The result shows that with the combined actions of 3-min steaming blanching together with color-protection from 1% phytic acid and 0.6% L-cysteine,the phenomenon of brown stain on the dried date can be effectively improved under the storage conditions of temperature at37?,and humidity at 80%.(2)Analyzed the effect of compound essential oil fumigation on the storage quality of dried grey jujube: under the conditions of temperature 37?,humidity 80%,with different concentrations of tea tree,lavender and citrus essential oils as fumigants,through the degree of browning,solubility The solids and the total number of colonies screened out 300 ?L/L tea tree essential oil,500 ?L/L lavender essential oil,and 80 ?L/L citrus essential oil.Taken together,the soluble protein,ascorbic acid content and many other indicators: the second group of 300 ?L/L tea tree + 80 ?L/L citrus essential oil fumigation group has the best quality effect,with a browning degree of 2.04 and a sensory score of 87.3 points.(3)The influence of different packaging on the storage quality of dried gray dates was discussed: three kinds of packaging materials: ordinary market packaging,kraft paper visual packaging,and transparent film packaging were used to package the dried gray dates and store them together with the CK group.Sugar,titratable acid,soluble protein,ascorbic acid content browning degree;comprehensive comparison,the visual packaging effect of kraft paper is better.(4)Optimized the design plan for the industrialized production of dried grey jujube storage: calculated and analyzed the processing plant,raw materials and equipment,investment and profit of dried grey jujube,and the annual profit of dried jujube with an annual output of 500 tons was 4,064,965.The payback period is 1.5 years,providing feasibility for the industrialization of the product.It is identified that after being pressed with steam blanching color protection,the inhibitor ratio of brown stain on dried date can reach 67.02%,T value at 0.213,L* value at 29.92;with the process of 300?L/L tea tree oil +80 ?L/L citrus oil,the sensory score of dried date is 87.3,and ratio of brown stain at2.04,which is lower by about 42% comparing to normal blank group.The loss of ingredients and effect of brown stain of the dried date with package has been slowed down at the storage,which provide reference for the industrialization of date production in Xinjiang in future.