Nutrition Program, School of Biological and Population Health Sciences, College of Public Health and Human Sciences, Oregon State University, Corvallis, OR, United States.
Department of Food Science and Technology, Oregon State University, Corvallis, OR, United States.
J Nutr. 2023 Sep;153(9):2598-2611. doi: 10.1016/j.tjnut.2023.07.001. Epub 2023 Jul 8.
Donor human milk banks use Holder pasteurization (HoP; 62.5°C, 30 min) to reduce pathogens in donor human milk, but this process damages some bioactive milk proteins.
We aimed to determine minimal parameters for high-pressure processing (HPP) to achieve >5-log reductions of relevant bacteria in human milk and how these parameters affect an array of bioactive proteins.
Pooled raw human milk inoculated with relevant pathogens (Enterococcus faecium, Staphylococcus aureus, Listeria monocytogenes, Cronobacter sakazakii) or microbial quality indicators (Bacillus subtilis and Paenibacillus spp. spores) at 7 log CFU/mL was processed at 300-500 MPa at 16-19°C (due to adiabatic heating) for 1-9 min. Surviving microbes were enumerated using standard plate counting methods. For raw milk, and HPP-treated and HoP-treated milk, the immunoreactivity of an array of bioactive proteins was assessed via ELISA and the activity of bile salt-stimulated lipase (BSSL) was determined via a colorimetric substrate assay.
Treatment at 500 MPa for 9 min resulted in >5-log reductions of all vegetative bacteria, but <1-log reduction in B. subtilis and Paenibacillus spores. HoP decreased immunoglobulin A (IgA), immunoglobulin M (IgM), immunoglobulin G, lactoferrin, elastase and polymeric immunoglobulin receptor (PIGR) concentrations, and BSSL activity. The treatment at 500 MPa for 9 min preserved more IgA, IgM, elastase, lactoferrin, PIGR, and BSSL than HoP. HoP and HPP treatments up to 500 MPa for 9 min caused no losses in osteopontin, lysozyme, α-lactalbumin and vascular endothelial growth factor.
Compared with HoP, HPP at 500 MPa for 9 min provides >5-log reduction of tested vegetative neonatal pathogens with improved retention of IgA, IgM, lactoferrin, elastase, PIGR, and BSSL in human milk.
捐赠人母乳银行使用 Holder 巴氏消毒法（HoP；62.5°C，30 分钟）来降低捐赠人母乳中的病原体，但该过程会破坏一些生物活性乳蛋白。
我们旨在确定高压处理（HPP）的最小参数，以实现人乳中相关细菌的>5 对数减少，并研究这些参数如何影响一系列生物活性蛋白。
将接种了相关病原体（屎肠球菌、金黄色葡萄球菌、单核细胞增生李斯特菌、阪崎克罗诺杆菌）或微生物质量指标（枯草芽孢杆菌和芽孢杆菌属孢子）的原始人乳以 7 个对数 CFU/mL 的浓度混合，在 16-19°C 下用 300-500 MPa 的压力处理 1-9 分钟（由于绝热加热）。使用标准平板计数法对存活的微生物进行计数。对于原始牛奶、HPP 处理的牛奶和 HoP 处理的牛奶，通过 ELISA 评估一系列生物活性蛋白的免疫反应性，并通过比色底物测定法测定胆汁盐刺激的脂肪酶（BSSL）的活性。
处理压力为 500 MPa，时间为 9 分钟，可使所有需氧菌减少>5 个对数，但枯草芽孢杆菌和芽孢杆菌孢子的减少不到 1 个对数。HoP 降低了免疫球蛋白 A（IgA）、免疫球蛋白 M（IgM）、免疫球蛋白 G、乳铁蛋白、弹性蛋白酶和多聚免疫球蛋白受体（PIGR）的浓度以及 BSSL 活性。500 MPa 处理 9 分钟可保留更多的 IgA、IgM、弹性蛋白酶、乳铁蛋白、PIGR 和 BSSL，优于 HoP。HoP 和 HPP 处理压力高达 500 MPa，处理时间 9 分钟，不会导致骨桥蛋白、溶菌酶、α-乳白蛋白和血管内皮生长因子的损失。
与 HoP 相比，500 MPa 的 HPP 处理 9 分钟可提供>5 个对数减少的测试新生病原体，同时保留更多的 IgA、IgM、乳铁蛋白、弹性蛋白酶、PIGR 和 BSSL 在母乳中。
