Comparison of effect of microwave sterilization and pasteurization on qualities of kiwi juice

This study was conducted to investigate the comparison of effects of microwave sterilization and pasteurization on nutrient components and physio-chemical properties of kiwi juice based on the achievement of commercial sterilization requirements separately. “Gui Chang” kiwi, produced from Xiuwen in Guizhou Province, which was used as raw materials for processing, and the effects of microwave sterilization and pasteurization on total number of bacteria, pH value, soluble solid content, color, total acid, total sugar, polyphonols, VCand SOD in kiwi juice were determined. The results showed that different sterilization methods had no significant effect on pH, soluble material, total sugar and total acid (p>0.05) when compared with control group. The content of VCin kiwi juice decreased after pasteurization (p<0.05) , while the content of polyphonols increased (p<0.05) . Compared with pasteurization, the microorganisms reduced by 99.99%, the ΔE value and the content of polyphenols decreased significantly (p<0.05) , while the content of VCincreased (p>0.05) after microwave sterilization. Those indicated that microwave sterilization could better maintain the color and nutrients in kiwi juice. Therefore, microwave sterilization technology not only achieved good bacterial effect but also to ensure maximum quality of kiwi juice.