Research Of Non-enzymatic Browning Mechanism And Browning Model Of Canned Chinese Chestnut In Syrup

Canned Chinese chestnut is the largest sales of Chinese chestnut products, however, kernel browning and turbid canned juice are two big problems that restrict its industrialization development. Based on the analysis of dynamic change of non-enzymatic browning during the process, the technological parameters were optimized, the dynamics of non-enzymatic browning during60days storage were analyzed, and mechanism of inhibition was also analyzed. The main research results were presented as follows:1. The non-enzymatic browning of canned Chinese chestnut during the processing was evaluated in this study. Single-factor experiments of canned Chinese chestnut at different cooking time, sterilization temperature, sterilization time and pH were carried out. In order to determine the technological parameters, changes of reducing sugar, soluble protein, tannin,5-hydroxymethyl furfural (5-HMF), browning degree (A420) and color parameters (lightness L*, redness a*and yellowness b*) during the key process steps were detected. The technological parameters determined were30min cooking time,110℃sterilization temperature and20min sterilization time.2. Change of qualities related to non-enzymatic browning in canned juice and chestnut kernel at different storage temperatures (4,25and60℃) for2months were evaluated in this study. Changes of reducing sugar, free amino acid, tannin,5-hydroxymethyfurfural (5-HMF) and browning degree (BD) were fitted with5kinds of kinetic models, and it was found that the first-kinetic model could better explain the kinetic changes of non-enzymatic browning in canned chestnut during storage. Changes between5-HMF and A420show linear relation during storage at the setting temperatures. The activation energy of5-HMF accumulating reaction in canned juice and chestnut kernel were23.03kJ/mol and26.41kJ/mol representatively, the activation energy of brown substances in canned juice and chestnur kernel were29.51kJ/mol and24.49kJ/mol.3. Addition of inhibition can reduce the loss of reducing sugar and free amino acid. The inhibition test showed that browning inhibitors used in canned chestnut were also inhibiting the third phase of Maillard reaction, forming melanoid from5-HMF, keeping the products in good sensory quality.