Fonterra Research and Development Centre, Palmerston North, New Zealand 4472.
Fonterra Research and Development Centre, Palmerston North, New Zealand 4472.
J Dairy Sci. 2024 Mar;107(3):1311-1333. doi: 10.3168/jds.2023-23893.
Whole milk powder (WMP) manufactured in New Zealand in 1907 was sent to the Antarctic continent with the Shackleton-led British Antarctic Expedition from 1907 to 1909. This powder was stored at ambient conditions at Shackleton's Hut at Cape Royds, Antarctica, for over 100 yr before a sample was collected on behalf of Fonterra by the Antarctic Heritage Trust. Having spent most of its existence both dried and in frozen storage, any deleterious reactions within the WMP would have been markedly retarded. The composition and some properties of the roller-dried Shackleton's WMP are reported along with those of 2 modern spray-dried New Zealand WMP. The Shackleton powder was less white and more yellow than the modern WMP and was composed of flakes rather than agglomerated particles, consistent with that expected of a roller-dried powder. Headspace analysis showed lipolytic and oxidative volatile compounds were present in the Shackleton WMP, indicting some deterioration of the milk either before powder manufacture or on storage of the finished product. On a moisture-free basis, the Shackleton WMP had higher protein, higher fat (with a markedly higher free fat level), higher ash, and a lower lactose level than the modern WMP. The lysine level was lower in the Shackleton WMP compared with the spray-dried powders, whereas the fatty acid composition was relatively similar. The sodium level was markedly higher in the Shackleton WMP compared with the spray-dried powder, which is probably due to the addition of an alkaline sodium salt to adjust the pH of the milk before roller drying. Lead, iron, and tin levels were markedly higher in the Shackleton WMP compared with the spray-dried powders, possibly due to the equipment used in powder manufacture and the tin-plated cases used for storage. The proteins in the Shackleton WMP were more lactosylated than in the spray-dried powders. The Shackleton WMP had a higher ratio of κ-casein A to B variants and a higher ratio of β-lactoglobulin B to A variants than the spray-dried powders, whereas the α-casein, β-casein, α-casein, and α-lactalbumin protein variants were similar in all powders. The total phospholipid content was markedly lower in the Shackleton WMP than the spray-dried powders, primarily due to a lower phosphatidylethanolamine concentration. The molecular species distributions within the phospholipid classes were generally similar in the 3 powders. Claims are sometimes encountered that the milk of today is different from that consumed by previous generations. However, this comparative study has shown that the Shackleton WMP was generally similar to modern WMP. Although differences in some components and properties were observed, these were attributable to the manufacturing equipment and processes used in the pioneering years of WMP manufacture.
1907 年在新西兰生产的全脂奶粉（WMP）随 1907 年至 1909 年沙克尔顿领导的英国南极探险队一起被运往南极大陆。在南极遗产信托基金（Antarctic Heritage Trust）代表恒天然（Fonterra）收集样本之前，该奶粉在沙克尔顿小屋（Shackleton's Hut）的常温条件下储存了 100 多年。由于它的大部分时间都处于干燥和冷冻储存状态，WMP 中的任何有害反应都会明显延迟。报告了滚筒干燥的沙克尔顿 WMP 的组成和一些性质，以及两种现代喷雾干燥的新西兰 WMP 的性质。与现代 WMP 相比，沙克尔顿奶粉的颜色更黄，更白，而且由薄片组成，而不是团聚的颗粒，这与预期的滚筒干燥粉末一致。顶空分析表明，脂肪分解和氧化挥发性化合物存在于沙克尔顿 WMP 中，表明在粉末制造之前或在成品储存期间，牛奶已经发生了一些变质。在无水的基础上，与现代 WMP 相比，沙克尔顿 WMP 的蛋白质、脂肪（游离脂肪水平明显较高）、灰分和乳糖含量较高。与喷雾干燥的粉末相比，沙克尔顿 WMP 的赖氨酸含量较低，而脂肪酸组成则相对相似。与喷雾干燥的粉末相比，沙克尔顿 WMP 的钠含量明显较高，这可能是由于在滚筒干燥前添加碱性钠盐来调节牛奶的 pH 值。与喷雾干燥的粉末相比，沙克尔顿 WMP 的铅、铁和锡含量明显较高，这可能是由于粉末制造中使用的设备和用于储存的镀锡铁皮盒所致。沙克尔顿 WMP 中的蛋白质比喷雾干燥的粉末更乳酰化。与喷雾干燥的粉末相比，沙克尔顿 WMP 的 κ-酪蛋白 A 与 B 变体的比例较高，β-乳球蛋白 B 与 A 变体的比例较高，而 α-酪蛋白、β-酪蛋白、α-酪蛋白和α-乳白蛋白的蛋白质变体在所有粉末中均相似。沙克尔顿 WMP 的总磷脂含量明显低于喷雾干燥的粉末，主要是由于磷脂酰乙醇胺浓度较低。在 3 种粉末中，磷脂类的分子种类分布一般相似。有人声称，如今的牛奶与前几代人所喝的牛奶不同。然而，这项比较研究表明，沙克尔顿 WMP 与现代 WMP 大致相似。尽管观察到一些成分和性质存在差异，但这些差异归因于 WMP 制造的开创性年代中使用的制造设备和工艺。
