School of Agriculture and Food Science, The University of Queensland, Saint Lucia, QLD, Australia.
School of Pharmacy, The University of Queensland, Saint Lucia, QLD, Australia.
J Hum Lact. 2023 May;39(2):300-307. doi: 10.1177/08903344221124870. Epub 2022 Sep 29.
The most utilized pasteurization method in donor human milk banks is Holder pasteurization (heating 62.5 °C for 30 min). However, many bioactive proteins are heat sensitive and are inactivated.
To determine the results of a range of heating regimes on the activities of xanthine oxidase, lactoperoxidase and lysozyme, the concentrations of immunoglobulin A and lactoferrin, as well as bacterial inactivation.
This prospective, cross-sectional, intervention study was designed to measure the influence of heating temperatures on bioactive components in donor human milk. Milk samples were processed at 40, 50, 55, 62.5, 75, 127 °C and the activities of the enzymes, and the concentration of immune proteins, were measured.
No bacterial colonies were detectable, using standard culture methods, after heating above 50 ºC. All proteins studied retained over 60% concentrations or activities when the pasteurization temperature was 50 ºC or lower, while their concentrations or activities were lost at higher temperatures. For lactoferrin, the residual concentration was above 80% when heating temperature was under 55 °C, while only 20% remained after Holder pasteurization. Both xanthine oxidase and lactoperoxidase had little residual activity when temperatures were above Holder pasteurization. Lysozyme retained a greater proportion of residual activity than other proteins, following heating at all temperatures.
The concentrations or activities of immune proteins and bioactive enzymes decreased when heated above 50 °C. The results of this study can be used to design temperature control guidance during alternative methods of pasteurization.
在供体人乳库中，最常用的巴氏消毒方法是Holder 巴氏消毒（加热至 62.5°C 持续 30 分钟）。然而，许多生物活性蛋白对热敏感，会失活。
确定一系列加热方案对黄嘌呤氧化酶、乳过氧化物酶和溶菌酶活性、免疫球蛋白 A 和乳铁蛋白浓度以及细菌失活的影响。
本前瞻性、横断面、干预研究旨在测量加热温度对供体人乳中生物活性成分的影响。牛奶样品在 40、50、55、62.5、75、127°C 下进行处理，并测量酶的活性和免疫蛋白的浓度。
使用标准培养方法，加热温度超过 50°C 后，无法检测到细菌菌落。所有研究的蛋白质在巴氏消毒温度为 50°C 或更低时保留超过 60%的浓度或活性，而在更高温度下则失去浓度或活性。对于乳铁蛋白，当加热温度低于 55°C 时，其残留浓度高于 80%，而 Holder 巴氏消毒后仅剩余 20%。当温度高于 Holder 巴氏消毒时，黄嘌呤氧化酶和乳过氧化物酶的残留活性很小。溶菌酶在所有温度下加热后，保留了更大比例的残留活性。
当加热温度超过 50°C 时，免疫蛋白和生物活性酶的浓度或活性会降低。本研究的结果可用于设计替代巴氏消毒方法中的温度控制指南。
