College of Food Science and Nutritional Engineering, China Agricultural University, China.
J Sci Food Agric. 2011 Mar 30;91(5):877-85. doi: 10.1002/jsfa.4260. Epub 2011 Jan 6.
Changes in activity of polyphenol oxidase (PPO), peroxidase (POD) and β-glucosidase, individual phenolic compounds other than anthocyanins, total phenols, monomeric anthocyanins, polymeric color and instrumental color of strawberry pulps were assessed after high hydrostatic pressure (HHP) (400-600 MPa 5-25 min(-1)) at room temperature.
β-Glucosidase was activated by 4.7-16.6% at 400 MPa 5-25 min(-1) and inactivated by 8.0-41.4% at 500 or 600 MPa. PPO and POD were inactivated at all pressures, the largest reduction in activity being 41.4%, 51.5% and 74.6%, respectively. The individual phenolic compounds and total phenols decreased at 400 MPa, but total phenols increased at 500 or 600 MPa. However, the monomeric anthocyanins, polymeric color and redness (a*) exhibited no change. HHP induced a decrease in lightness (L*) and an increase in yellowness (b*) at 400 MPa, but no significant alteration in L* value and b* value at 500 or 600 MPa was observed; this was attributed to higher residual activity of PPO, POD and β-glucosidase at 400 MPa. Total color difference (ΔE) was ≥5 at 400 MPa and ≤3 at 500 or 600 MPa.
HHP effectively retained anthocyanins, phenolic compounds and color of strawberry pulps, and partly inactivated enzymes.
室温下，采用高静压（HHP）（400-600 MPa 5-25 min(-1))对草莓浆的多酚氧化酶（PPO）、过氧化物酶（POD）和β-葡萄糖苷酶的活性变化、除花色苷以外的其它酚类化合物、总酚、单体花青素、聚合色素和仪器颜色进行了评估。
在 400 MPa 5-25 min(-1)下，β-葡萄糖苷酶的活性提高了 4.7-16.6%，而在 500 或 600 MPa 下则失活了 8.0-41.4%。PPO 和 POD 在所有压力下均失活，活性降低最大分别为 41.4%、51.5%和 74.6%。除 400 MPa 外，各酚类化合物和总酚含量降低，但 500 或 600 MPa 时总酚含量增加。然而，单体花青素、聚合色素和红色（a*）没有变化。HHP 在 400 MPa 下导致亮度（L*）降低，黄色（b*）增加，但在 500 或 600 MPa 下 L值和 b值没有明显变化；这归因于 400 MPa 下 PPO、POD 和β-葡萄糖苷酶的残余活性较高。总色差（ΔE）在 400 MPa 时≥5，在 500 或 600 MPa 时≤3。
HHP 能有效保持草莓浆的花青素、酚类化合物和颜色，部分酶失活。
