| Jujube is rich in resources in Xinjiang,candied jujube is as a dried product of dates,The processing products of jujube fruits with distinctive texture and flavor have been formed.In this study,three mature jujube with white ripe stage,crisp ripe stage and full ripe stage were used as raw materials,The color protection parameters,sugared process parameters and drying time of three mature Jun jujube were studied.In the process of processing,the related indicators affecting Browning were analyzed,and three packaging materials,PE,PET/NY/AL/CPP and PET/AL/PET,were used to package jujube,and the correlation between Browning rules of jujube with different packaging materials in the storage process was explored.The main research results are as follows:(1)Taking Junzao as raw material,the best ratio of compound color protector was screened out as V_C1.25 g/L,citric acid 2.00 g/L,Na Cl 25.00 g/L,sulfite 1.25 g/L by single factor and orthogonal test.(2)The optimal process parameters of the secondary atmospheric cooking process were as foll ows:when the concentration of sugar solution was 40%-45%,the first cooking time and the second cooking time were both 15min,and the first impregnation time and the second impregnation time were both 12 h,so the sugared effect of jujube was the best.(3)Response surface analysis was used to determine the optimal process parameters of vacuum sugar infiltration:when the concentration of sugar solution was 40%-45%,the first cooking time was 15 min,the jujube fruit was placed in a vacuum of 0.10 MPa,the vacuum time was 30 min,and the vacuum immersion time was 150 min,so the vacuum sugar infiltration effect of jujube was the best.(4)After the secondary atmospheric pressure cooking and vacuum sugar infiltration,the jujube was extracted from the sugar solution and dried and then put into a thermostatic oven for drying.With the water content and the product showing that it is not sticky to hands as the index,the optimal drying time of jujube was determined to be 24 h at 55?.(5)When using the principal component for data analysis,in the second atmospheric cooked sugar process,the cumulative variance contribution rate of 75.05%of the principal component 1,2sugar in vacuum impregnation process,the cumulative variance contribution rate of 76.28%of the principal component 1,2analysis process processing under two different maturity jujube as raw material,influence of Browning index is slightly different,in general,ascorbic acid content,5-HMF results,affecting jujube is the total phenol content in the process of processing the main cause of Browning.(6)In jujube storage process,the use of principal component analysis data secondary atmospheric cooked permeability sugar processing technology of jujube during storage with three kinds of packaging material influence Browning index of the first principal component to the total phenol content,chlorophyll content,influence of Browning index of the second principal component for ascorbic acid content,the content of 5-results and titratable acid content.Among the three kinds of maturity,the raw materials in the white ripening stage had a strong effect on the Browning.In the process of storage with three kinds of packaging materials,the first principal components of the processed jujube were ascorbic acid content,total phenol content and 5-HMF content.The content of titratable acid and chlorophyll were the second main components affecting Browning.Among the three kinds of maturity,the raw materials in the brittle ripening stage had a strong effect on Browning during storage.PET/NY/AL/CPP and PET/AL/PET are better than PE in three kinds of packaging materials. |
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