超高压处理对复合果汁微生物和品质的影响

Effects of High Hydrostatic Pressure Treatment on Microorganism and Quality of Composite Juice

以苹果、石榴、布朗李制备复合果汁,对不同配比的复合果汁进行感官评价以确定最佳配比,并研究超高压(HHP)处理参数(处理压力、保压时间)对复合果汁微生物和品质的影响。通过感官评价确定复合果汁的最佳复配比例为m苹果汁∶m石榴汁∶m布朗李浆=16∶3∶1。在400 MPa/5 min,500 MPa/1 min,500 MPa/3 min,500 MPa/5 min超高压处理条件下菌落总数、霉菌和酵母数均符合GB 7101-2015《食品安全国家标准饮料》要求。与未处理组相比,HHP处理和热处理后样品的pH值、可溶性固形物含量和色泽均无显著性变化。HHP处理样品的总酚和抗坏血酸含量与热处理组样品无显著性差异,而HHP处理样品的DPPH自由基清除能力和铁还原能力显著高于热处理组样品。其中,HHP处理组DPPH自由基清除能力较热处理组高8.57%~18.10%,铁还原能力高11.50%~24.78%。HHP处理使样品的黏度上升,而热处理使样品的黏度下降。HHP处理和热处理都使样品的挥发性香气成分发生改变,而热处理后蒸煮味成分含量增加更多。与热处理相比,HHP处理对内源酶活性的钝化能力较弱,多酚氧化酶、过氧化物酶和脂肪氧化酶残存酶活分别在65.13%~76.97%,75.00%~85.42%,75.00%~85.00%范围,而热处理组为15.35%,7.29%,45.00%。

In this paper,apple,pomegranate and brown plum were used as raw materials to prepare composite juice.Sensory evaluation of different proportions of composite juice was carried out to determine the best ratio,and the effects of high hydrostatic pressure(HHP)treatment parameters(treatment pressure,holding time)on the microbes and quality of composite juice were studied.The optimal compounding ratio of the composite juice was mapple juice∶mpomegranate juice∶mbrown plum pulp=16∶3∶1.After 400 MPa/5 min,500 MPa/1 min,500 MPa/3 min and 500 MPa/5 min treatment,the counts of total aerobic bacteria and yeasts and molds met the requirements of‘Chinese National standards for food safety Beverages GB 7101-2015’.Compared with the untreated group,HHP treatment and heat treatment had no significant effects on the pH,total soluble solids(TSS)and color of the sample.The total phenol and ascorbic acid content of HHP-treated samples were not significantly different from heat-treated ones,but the DPPH removal ability and ferric ion reducing antioxidant power(FRAP)of the HHP-treated samples were significantly higher than heat-treated ones.The DPPH removal ability of HHP-treated samples was 8.57%-18.10%higher than heat-treated ones,and the FRAP was 11.50%-24.78%higher.HHP treatment increased the viscosity of the samples,while heat treatment reduced the viscosity of the samples.Both HHP treatment and heat treatment changed the volatile aroma components of the samples,but the content of the retort component after heat treatment increased more.The passivation effect of HHP treatment on endogenous enzyme activity was worse than that of heat treatment,and the residual enzyme activity of polyphenol oxidase(PPO),peroxidase(POD)and lipoxygenase(LOX)was between 65.13%-76.97%,75.00%-85.42%and 75.00%-85.00%in HHP-treated samples,respectively,while 15.35%,7.29%and 45.00%in heat-treated ones.