Scientists have opened time capsules with Antarctic milk powder aged 117 years

As the popularity of alternative dairy products continues to grow, the centuries-old question about cow’s milk still remains open. Scientists were able to answer the question “how are today’s dairy products different from what previous generations consumed?”

Experts have opened a 117-year-old can of whole milk powder that was carried during Sir Ernest Shackleton’s British Antarctic Expedition in the early 20th century. A study published in the Journal of Dairy Science found that despite advances in cow breeding and changes in farming practices, the milk of today and the past has more similarities than differences.

The powdered milk used in the study was produced by the New Zealand brand Defiance in 1907. On New Year’s Day 1908, Shackleton and his crew set sail aboard the ship Nimrod to be the first to set foot at the South Pole. There were a lot of dairy products on board, including 453 kilograms of whole milk powder, 82 kilograms of butter and two packages of cheese.

About a century later, one remaining container of Defiance whole milk powder was discovered during restoration work as part of an Antarctic Heritage Trust restoration project. The milk powder was frozen in time and ice at Shackelton Base Camp for 100 years.

“Shackelton’s milk powder is perhaps the best-preserved example produced in the early years of commercial milk powder production, and its discovery gives us a once-in-a-lifetime chance to understand the similarities and differences between roll-dry milk powders produced over 100 years ago. , and modern spray-dried milk powder colleagues,” explains chemist Skelte J. Anema.

According to his point of view, milk powder was prepared by roller drying before evaporation using vacuum. Boiling milk was poured between two rotating cylinders heated by steam to evaporate the water. A thin layer of milk powder remained, which was then crushed and sifted. Although scientists knew that these early milk powders were not as complex as those available today, they were not sure what other differences existed.

In the study, the team analyzed several hundred grams of Defiance milk. They decided to compare it with two modern commercial whole milk powders that had not been spray-dried. They compared the composition of milk’s major and micronutrient components, proteins, fatty acids and phospholipids. They also studied the microstructural properties, color and volatile components of different whole milk powder samples.

“Despite more than a century of differences between the samples, the composition of the main components and the detailed description of proteins, fats and minor components have not changed dramatically over the years,” Anema said.

The fatty acid, phospholipid and protein compositions of the samples were similar. The major mineral components in the samples were also relatively similar, with the exception of higher levels of lead, tin, iron and other trace elements found in the 100-year-old whole milk powder. These minerals likely came from the tin in which the powder was stored, as well as from the equipment and water supply used during this time period. Using stainless steel and better quality water has eliminated this problem in modern milk powders, the researchers say.

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

“Possibly due to imperfect collection and storage of raw milk before drying, but it is much more likely that – even frozen – storage in an open jar for a century will lead to prolonged oxidation,” the chemist explained.

Despite the striking similarities between the milk samples, the team notes that modern spray-dried whole milk powder is significantly superior in quality. It looks better and dissolves more easily in water.

This unique Antarctic time capsule continues to provide insight into dairy production methods of the past and their evolution over time.

“The samples are a testament to the importance of dairy products, which are rich in protein and energy and are also flexible enough to be ground into powder for ease of transport, preparation and consumption,” Anema said.