Correlation Analysis of Browning of Jujube During Roasting

The experiment used Junzao jujube with different maturity in Aksu area of Xinjiang as the test material, using the normal pressure twice boiling sugar infiltration process, roasting constant temperature of 55 ℃, with total phenols, ascorbic acid content(Vitamin C), chlorophyll content, total free amino acids, 5-HMF as the compratrate content, etc. It combined correlation analysis with principal component analysis to explore the browning of jujube during the roasting stage.The results showed that the content of browning factors varied with the drying time of jujube at different maturity.Correlation analysis found that the color difference of the three maturity dates was significantly positively correlated with total phenol, chlorophyll and other indexes (P<0.01), ascorbic acid content was significantly negatively correlated with 5-HMF index (P<0.01).The principal component analysis showed that maturity, 5-HMF and ascorbic acid content were the main factors affecting the browning of jujube during the roasting process.In addition, compared with the control group, jujube treated with color preserving treatment (V_C 1.25 g/kg, sodium pyrosulfite 1.25 g/kg, citric acid 3 g/kg, NaCl 25 g/kg) had a significant effect on browning inhibition.It can be seen that the browning of jujube in the baking stage is a complicated non-enzymatic browning process, which also provides a theoretical basis for further research.