热杀菌条件对NFC冬枣汁成分及抗氧化活性的影响研究

为了研究不同热杀菌条件对NFC冬枣汁理化性质、活性成分及抗氧化活性的影响,本文以冬枣为研究对象,设置了低温长时杀菌(75℃,5、10、15、20、25 min)和高温短时杀菌(90℃,0.25、0.50、0.75、1.00、1.50 min)两个处理,考察了NFC冬枣汁的可溶性固形物含量、pH值、总酸含量、VC含量、DPPH清除率、亚铁离子还原率等指标。研究结果表明,两种杀菌方式对NFC冬枣汁基本理化性质影响不显著(P>0.05)。相比于低温长时杀菌,高温短时杀菌的△E值更低,更能保持冬枣汁原有的色泽。两种杀菌处理后多酚、VC含量均显著降低(P<0.05),低温长时杀菌25 min后VC含量未检出,抗氧化活性也显著低于高温短时杀菌(P<0.05)。因此,通过对NFC冬枣汁品质变化的分析,发现高温短时杀菌能更好地保持原有的色泽和营养成分。

Effects of Different Heat Sterilization Conditions on the Composition and Antioxidant Activity of NFC"Dongzao"Jujube Juice

In order to study the effects of different heat sterilization conditions on the physical and chemical properties,active ingredients and antioxidant activity of NFC"Dongzao"jujube juice,this paper took"Dongzao"jujube as the research object,and set up low temperature long-term sterilization(75℃,5,10,15,20,25 min)and high temperature short-time sterilization(90℃,0.25,0.50,0.75,1.00,1.50 min)two treatments,investigated the soluble solid content,pH value,total acid content,VC content,DPPH removal rate,Fe2+reduction rate,etc.The results showed that the two sterilization methods had no significant effect on the basic physical and chemical properties of NFC"Dongzao"jujube juice(P>0.05).Compared with low temperature long-term sterilization,the△E value of high temperature short-time sterilization was lower,which could better maintain the original color of jujube juice.The content of polyphenols and VC were significantly reduced after the two sterilization treatments(P<0.05),and the VC content was not detected after 25 min of low temperature long-term sterilization,and the antioxidant activity was significantly lower than that of high temperature short-time sterilization(P<0.05).Therefore,through the analysis of the quality changes of NFC"Dongzao"jujube juice,it is found that high temperature short-time sterilization can better maintain the original color and nutrient content.