超高压处理对富含叶酸果蔬泥微生物和品质的影响

Effect of high hydrostatic pressure treatment on microbes and quality of folic acid-rich fruit and vegetable puree

以南瓜、牛油果、蜂蜜、即食酵母粉为原料,制备富含叶酸的复合果蔬泥,与热处理(90℃,1.5 min)进行对比,探究超高压(High hydrostatic pressure,HHP)处理(400、500 MPa,1、5、10 min)对果蔬泥杀菌效果和品质的影响。通过感官评价确定果蔬泥的最佳复配比例为南瓜:牛油果6:1(w/w),蜂蜜添加量10%(w/w),酵母粉添加量2%(w/w)。结果表明:在热处理及HHP条件为400 MPa/5 min、400 MPa/10 min、500 MPa/1 min、500 MPa/5 min和500 MPa/10 min下,菌落总数均可降至2 lg cfu/g以下,霉菌酵母菌降至1 lg cfu/g以下。HHP处理的样品可溶性固形物(TSS)、抗坏血酸(Vc)和清除·DPPH能力与热处理组对比无显著差异,而总酚、叶酸、铁还原能力(FRAP)显著高于热处理组(P>0.05),分别较热处理组高出25%~50%、25%~45%、25%~50%。与热处理相比,HHP处理对内源酶活性钝化能力较弱,多酚氧化酶(Polyphenol oxidase,PPO)和过氧化物酶(Peroxidase,POD)残存酶活分别在75%~85%和65%~95%,而热处理组则为38%和71%。此外,热处理和HHP处理均使产品黏度增加,但热处理黏度增加更明显。

In this paper, pumpkin, avocado, honey and instant yeast powder were used as raw materials to prepare folic acid-rich composite fruit and vegetable puree, which was compared with heat treatment(90 ℃, 1.5 min) to explore the effect of high hydrostatic pressure(HHP) treatment(400 MPa, 500 MPa;1 min, 5 min, 10 min) on the bactericidal effect and quality of fruit and vegetable mud. The optimal compounding ratio of the fruit and vegetable puree was determined by sensory evaluation as pumpkin:avocado 6:1(w/w), honey addition amount 10%(w/w), and yeast powder addition amount 2%(w/w). The results showed that the total number of colonies could be reduced to 2 lg cfu/g under heat treatment and HHP conditions of 400 MPa/5 min, 400 MPa/10 min, 500 MPa/1 min, 500 MPa/5 min and 500 MPa/10 min. Hereinafter, the mold yeast is reduced to less than 1 lg cfu/g. The HHP-treated samples had no significant difference in soluble solids(TSS), ascorbic acid(Vc) and DPPH removal compared with the heat treatment group, while total phenol, folic acid and iron reduction ability(FRAP) were significantly higher than that of the heat treatment group(P>0.05), respectively, 25%~50%, 25%~45%, 25%~50% higher than the heat treatment group. Compared with heat treatment, HHP treatment has weaker inactivation ability for endogenous enzyme activity, and residual activities of polyphenol oxidase(POO) and peroxidase(POD) are 75%~85% and 65%~95%, respectively. while the heat treated group was 38% and 71%. In addition, both the heat treatment and the HHP treatment increase the viscosity of the product, but the viscosity increase of the heat treatment is more pronounced.