Breaking a 117-year-old milk capsule in Antarctica

While dairy alternatives like almond, oat and soy milk continue to grow in popularity, an age-old question about cow’s milk still remains. How is today’s dairy different from what previous generations consumed?

Some clues are now emerging in the form of 117-year-old whole milk powder that was carried on Sir Ernest Shackleton’s British Antarctic Expedition in the early 20th century. A study published in the March 2024 issue of Journal of Dairy Science found that despite progress in selective cow breeding and changes in farm practices, milk from the past and present have more similarities than differences.

of Nimrod’s expedition

The powdered milk under study was made by the Defiance brand of New Zealand in 1907. On New Year’s Day 1908, Shackleton and his crew aboard the ship Nimrod set sail on a quest to be the first to set foot on the South Pole. of Nimrod was well stocked with dairy, including 1,000 pounds of whole milk powder, 192 pounds of butter, and two cases of cheese. The crew would make it further south than any man had previously known and would make it within 100 nautical miles of the South Pole and leave their base camp and its supplies behind.

The top left photo (A) shows the tin-lined can of Defiance brand dry milk found in Shackleton's Cape Royds base camp hut, with a close-up of the label in the bottom photo (C) (courtesy of Antarctic Heritage Trust, Christchurch, New Zealand).  The top right photograph (B) is of the Joseph Nathan & Sons Bunnythorpe Defiance dried milk factory circa 1904 (courtesy of Massey University, Palmerston North, New Zealand).
The top left photo (A) shows the tin-lined can of Defiance brand dry milk found in Shackleton’s Cape Royds base camp hut, with a close-up of the label in the bottom photo (C) (courtesy of the Antarctic Heritage Trust, Christchurch, New Zealand). The top right photograph (B) is of the Joseph Nathan & Sons Bunnythorpe Defiance dried milk factory circa 1904 (courtesy of Massey University, Palmerston North, New Zealand).

About a century later, a remaining container of Defiance whole milk powder was discovered during a restoration project by the Antarctic Heritage Trust’s restoration project. The powdered milk had been frozen in time and the ice at Shackelton’s base camp for 100 years.

Shackleton’s dried milk is perhaps the best-preserved sample produced during the pioneering years of commercial milk powder production, and its discovery gives us a once-in-a-lifetime chance to understand the similarities and differences between a roller-dried milk powder. produced over 100 years ago with modern spray-dried counterparts,” Skelte G. Anema, a study co-author and chemist at the Fonterra Research and Development Center in New Zealand, said in a statement.

[Related: Ancient milk-drinkers were just fine with their lactose intolerance–until famine struck.]

According to Anema, before vacuum evaporation, milk powders were made by a roller drying process. Hot milk was poured between two rotating cylinders heated by steam so that the water could evaporate. A thin sheet of dried milk was left behind which was then ground and sieved. While scientists knew these early milk powders weren’t as sophisticated as those available today, they weren’t sure what other differences existed.

Analyzing milk powders

In the study, the team analyzed several hundred grams of 100-plus-year-old Defiance milk. They decided to compare it to two modern, non-instantized, spray-dried commercial samples of whole milk powder. They compared the composition of the main and trace components of milk, proteins, fatty acids and phospholipids. They also looked at microstructural properties, color and volatile components in different whole milk powder samples.

“Despite more than a century between samples, the composition of many components and proteins, fats and minor components have not changed drastically in the intervening years,” said Anema.

The fatty acid composition, phospholipid composition and protein composition of the samples were generally similar. The major mineral constituents between the samples were also relatively the same, except for the higher levels of lead, tin, iron and other trace minerals found in the Shackleton whole milk powder. These minerals likely came from the tin-lined can in which the powder was stored and the equipment and water supply used during that time period. Using stainless steel and better water has eliminated that problem from modern milk powders, according to the team.

Another notable difference in the Shackleton milk samples was the presence of volatile aroma compounds associated with oxidation.

[Related: Tending Sir Ernest’s Legacy: An Interview with Alexandra Shackleton.]

“Perhaps from less-than-ideal collection and storage of raw milk before drying, but it is far more likely that—even under frozen conditions—storing in an open can for a century will result in continued oxidation,” Anema said. .

Despite the remarkable similarities between the milk samples, the team points out that modern spray-dried whole milk powders are clearly superior in terms of powder quality. They look better and dissolve more easily in water.

This unique Antarctic time capsule still offers a glimpse into dairy food production methods of the past and its evolution over time.

“The Shackleton samples are a testament to the importance of dairy products – which are rich in protein and energy, as well as flexible enough to be powdered for easy transport, preparation and consumption,” said Anema.

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