Effects Of Processing And Storage On V_c And Volatile Organic Compounds In Orange Juice

With the development of juice industry, people are paying more and more attention to the nutrients and flavor of juice, which brings us to conduct more research about its particularity such as Vc and volatile compounds. In order to get the best quality of orange juice, it was necessary to determinate the best method to produce and the ideal way to preserve the entire important components. In this study, the organoleptic quality, the content of polysaccharide and VC and volatile compounds of freshly squeezed juice, flash pasteurization juice and long pasteurization juice from Citrus Reticulata × Citrus Sinensis were analyzed. The main results of this research were as follows:1 The organoleptic quality of freshly squeezed juice gradually decreased with the prolongation of storage time and the increasing of the temperature; Compared with flash pasteurization juice, the long pasteurization juice showed a better stability of pH,viscosity, color and other organoleptic quality with the prolongation of storage time and increasing of the temperature.2 The content of polysaccharide in different samples were: flash pasteurization juice>long pasteurization juice> freshly squeezed juice. The content of polysaccharide of freshly squeezed juice decreased with the prolongation of storage time and increased with the rising of the temperature. The storage time and temperature had no significant effects on the polysaccharide in pasteurization juice. Meanwile, it was found that polysaccharide were mainly composed of arabinose, rhamnose and mannose and other monosaccharides. The content of Vc in different samples were:freshly squeezed juice> flash pasteurization juice> long pasteurization juice. The content of Vc gradually decreased with the prolongation of storage time and increasing of the temperature.3 Electronic nose could effectively distinguish three different juice samples. 25, 23 and 22 active aromas were respectively identified in freshly squeezed juice, flash pasteurization juice and long pasteurization juice by GC-O, in which esters and acids were the main active compounds. 75, 67 and 64 volatile compounds were respectively identified in freshly squeezed juice, flash pasteurization juice and long pasteurization juice by GC-MS, in which terpenes and esters were the main volatile compounds. At 20℃,the main volatile compounds in pasteurization juice had no significant changes with the prolongation of storage time.