Zhou Shichu, Zhang Xin, Fan Rongbo, Wang Jun, Han Rongwei, Bu Dengpan, Yang Yongxin
College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, Shandong, China 266109.
College of Animal Science and Technology, Qingdao Agricultural University, Qingdao, Shandong, China 266109.
J Dairy Sci. 2025 Mar;108(3):2303-2314. doi: 10.3168/jds.2024-25868. Epub 2024 Dec 18.
Changes in the structure and composition of milk fat globules in spray- and freeze-dried milk powders have recently garnered notable attention. This study investigated changes in milk fat globular membrane (MFGM) proteins from bovine, goat, and horse milk powders, both spray- and freeze-dried, using a label-free proteomic approach, and quantified surface free fatty acids and their composition using GC. The results showed that several proteins, including α-CN and β-LG, increased, whereas fibrinogen α and β chain and mucin-1 decreased in the MFGM fractions of the studied spray-dried milk powders. Additionally, lactoperoxidase and polymeric immunoglobulin receptor levels were elevated in the studied freeze-dried milk powders. Several proteins exhibited variations in both dried milk powders depending on the species; of these, nucleobindin-1, complement C3, and sulfhydryl oxidase were increased in spray-dried bovine and goat milk powders, and lactoferrin was increased in freeze-dried horse milk powder, compared with their raw milk counterparts. Conversely, butyrophilin subfamily 1 member A1 and xanthine dehydrogenase/oxidase were decreased in spray-dried bovine and goat milk powders, S100 calcium-binding protein and aldehyde dehydrogenase were decreased in freeze-dried bovine and goat milk powders, and mucin-4 and paraoxonase were decreased in horse milk powder. Additionally, spray-dried milk powders had lower surface free fatty acid contents than freeze-dried milk powders. The findings underscore that drying methods exert varied effects on MFGM components of the studied milk sources, thereby providing a valuable reference for improving the nutritional quality of dried dairy products.
喷雾干燥和冷冻干燥奶粉中乳脂肪球的结构和组成变化最近受到了显著关注。本研究采用无标记蛋白质组学方法，调查了喷雾干燥和冷冻干燥的牛、山羊和马奶粉中乳脂肪球膜（MFGM）蛋白的变化，并使用气相色谱法对表面游离脂肪酸及其组成进行了定量。结果表明，在所研究的喷雾干燥奶粉的MFGM组分中，包括α-酪蛋白和β-乳球蛋白在内的几种蛋白质增加，而纤维蛋白原α链和β链以及粘蛋白-1减少。此外，在所研究的冷冻干燥奶粉中，乳过氧化物酶和聚合免疫球蛋白受体水平升高。根据物种不同，几种蛋白质在两种干燥奶粉中均表现出差异；其中，与原料乳相比，喷雾干燥的牛和山羊奶粉中核结合蛋白-1、补体C3和巯基氧化酶增加，冷冻干燥的马奶粉中乳铁蛋白增加。相反，喷雾干燥的牛和山羊奶粉中嗜乳脂蛋白亚家族1成员A1和黄嘌呤脱氢酶/氧化酶减少，冷冻干燥的牛和山羊奶粉中S100钙结合蛋白和醛脱氢酶减少，马奶粉中粘蛋白-4和对氧磷酶减少。此外，喷雾干燥奶粉的表面游离脂肪酸含量低于冷冻干燥奶粉。这些发现强调了干燥方法对所研究乳源的MFGM成分有不同影响，从而为提高干燥乳制品的营养质量提供了有价值的参考。
