Milk powder originating from New Zealand in 1907 and subsequently shipped to Antarctica's South Pole was uncovered after more than a century. This revelation has provided dairy researchers with the opportunity to investigate whether the milk presently consumed exhibits any variances from that consumed by previous generations.
In a recent comparative study showcased in the Journal of Dairy Science, published jointly by the American Dairy Science Association and Elsevier, scholars examined historical data to uncover that despite strides in selective breeding and shifts in farming techniques, the composition of milk from earlier periods closely mirrors that of contemporary milk. This highlights the lasting importance of milk as a fundamental element of human nutrition.
Ernest Shackleton's British Antarctic Expedition began on January 1, 1908, with the departure of the ship Nimrod from Lyttelton, New Zealand. Their goal was to accomplish the unprecedented achievement of being the first to set foot on the South Pole.
Amidst the lively atmosphere of the bustling wharf, the vessel was laden with dairy supplies: 1,000 pounds of dried whole milk powder, 192 pounds of butter, and two cases of cheese. Shackleton and his crew were embarking on an unprecedented expedition, aiming to journey farther south than any previous endeavor — within 100 nautical miles of the Pole — before setting up their base camp.
A century later, the Antarctic Heritage Trust restoration project revealed the solitary remaining container of Defiance brand whole milk powder, preserved within Shackleton's base camp for a hundred years.
Skelte G. Anema, the lead research scientist at Fonterra Research and Development Centre in Palmerston North, New Zealand, expanded on the importance of this discovery.
According to Anema, the discovery of the Shackleton dried milk presents an invaluable chance to examine the differences and similarities between milk powder production methods of the past and present. He noted that before the advent of vacuum-assisted evaporation, roller-drying involved pouring boiling-hot milk between two steam-heated revolving cylinders to evaporate water, resulting in a thin sheet of dried milk that underwent milling and sieving.
While it's understood that early milk powders lacked the sophistication of modern counterparts, what additional disparities were present?
Assisted by the Antarctic Heritage Trust, Anema and a team of scientists from the Fonterra Research and Development Centre analyzed several hundred grams of Defiance milk. They juxtaposed it with two contemporary commercial spray-dried whole milk powder samples from Fonterra.
Their examination encompassed a comparison of the primary component makeup, both major and trace mineral compositions, protein makeup, fatty acid constitution, phospholipid configuration, microstructural attributes, color examination, and analysis of volatile components among the varied whole milk powder samples.
Surprisingly, the findings contradicted assertions of milk alterations over time.
Anema further explained, "Despite a span of more than a century between the samples, there hasn't been a significant change in the composition of major constituents and specific proteins, fats, and minor elements over the years."
Overall, the fatty acid, phospholipid, and protein compositions, encompassing variations in casein and whey proteins, exhibited remarkable similarity.
Moreover, the primary mineral components showed uniformity across the samples, except for elevated levels of lead, tin, iron, and various trace minerals detected in the Shackleton whole milk powder. These variances are probably associated with the tin-plated storage container and the equipment and water sources utilized during that period.
Anema highlighted, "These challenges have mostly been addressed in modern milk powders by employing stainless steel equipment and utilizing high-quality water sources."
Additionally, a noticeable distinction was observed in the presence of oxidation-related volatile aroma compounds in the Shackleton samples.
Anema suggested, "This might be due to inadequate collection and storage of the raw milk before drying, but it's more probable that, despite being frozen, prolonged storage in an open tin for a century would lead to ongoing oxidation."
Despite the notable similarities, the team emphasized that modern spray-dried whole milk powders offer significantly improved powder quality, particularly in terms of appearance and their ease of dissolution in water.
On the whole, this Antarctic artifact provides a rare and valuable glimpse into the development of dairy food production, shedding light on the advancements achieved by the dairy sector and its enduring influence.
Anema emphasized, "The Shackleton samples serve as a testament to the significance of dairy products, which are abundant in protein and energy, and versatile enough to be converted into powder for convenient transport, preparation, and consumption."
Whether in the early stages of the twentieth century or in the present day, these outcomes underscore the essential role of dairy products as a cornerstone of human nutrition, fueling our discoveries across different eras.