As dairy alternate options similar to almond, oat, and soy milk proceed to develop in reputation, an centuries outdated query relating to cow’s milk nonetheless stays. How does at this time’s dairy differ from what earlier generations consumed?
Some clues are actually rising within the type of some 117-year-old complete milk powder that was transported on Sir Ernest Shackleton’s British Antarctic Expedition within the early twentieth Century. A examine revealed within the March 2024 subject of the Journal of Dairy Science discovered that regardless of development in selective cow breeding and modifications to farm practices, milk from the current and previous have extra similarities than variations.
The Nimrod expedition
The powdered milk within the examine was made by New Zealand’s Defiance model in 1907. On New Year’s Day in 1908, Shackleton and his crew aboard the ship Nimrod set sail on a quest to be the primary to set foot on the South Pole. The Nimrod was nicely stocked with dairy, together with 1,000 kilos of dried complete milk powder, 192 kilos of butter, and two instances of cheese. The crew would make it farther south than any recognized human had been earlier than and made it inside 100 nautical miles of the South Pole and left their base camp and its provides behind.
About a century later, one remaining container of Defiance complete milk powder was uncovered throughout a restoration challenge by the Antarctic Heritage Trust restoration challenge. The milk powder had been frozen in time and ice at Shackelton’s base camp for 100 years.
“The Shackleton dried milk is possibly the best-preserved sample manufactured 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 manufactured over 100 years ago with modern spray-dried counterparts,” Skelte G. Anema, a examine co-author and chemist at Fonterra Research and Development Centre in New Zealand, mentioned in a assertion.
[Related: Ancient milk-drinkers were just fine with their lactose intolerance–until famine struck.]
According to Anema, earlier than vacuum-assisted evaporation, milk powders had been made by a roller-drying course of. Boiling-hot milk was poured between two steam-heated revolving cylinders in order that the water evaporated. A skinny sheet of dried milk was left behind that was then milled and sieved. While scientists knew that these early milk powders weren’t as refined as these out there at this time, they weren’t certain what different variations existed.
Analyzing milk powders
In the examine, the crew analyzed a few hundred grams of the 100 plus year-old Defiance milk. They got down to examine it with two modern-day industrial, non-instantized and spray-dried complete milk powder samples. They in contrast the composition of the milk’s main and hint parts, proteins, fatty acids, and phospholipids. They additionally appeared on the microstructural properties, shade, and risky parts within the totally different complete milk powder samples.
“Despite more than a century between the samples, the composition of bulk components and detailed protein, fat, and minor components have not changed drastically in the intervening years,” mentioned Anema.
The fatty acid composition, phospholipid composition, and protein composition of the samples had been usually related. The main mineral parts between the samples had been additionally comparatively alike, aside from increased ranges of lead, tin, iron, and different hint minerals discovered within the Shackleton complete milk powder. These minerals seemingly got here from the tin-plated can the powder was saved in and the tools and water provide used throughout that time interval. Using chrome steel and higher water has eradicated that subject from trendy milk powders, based on the crew.
Another notable distinction within the Shackleton milk samples was the presence of oxidation-related risky aroma compounds.
[Related: Tending Sir Ernest’s Legacy: An Interview with Alexandra Shackleton.]
“Perhaps from less-than-ideal collection and storage of the raw milk before drying, but it’s much more likely that—even in frozen conditions—being stored in an open tin for a century is going to result in continued oxidation,” mentioned Anema.
Despite the outstanding similarities between the milk samples, the crew factors out that trendy spray-dried complete milk powders are considerably superior by way of the powder high quality. They look higher and dissolve in water extra simply.
This distinctive Antarctic time capsule nonetheless supplies a glimpse into dairy meals manufacturing strategies of the previous 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,” mentioned Anema.