Richard Evershed, a biogeochemist at the University of Bristol, has used a new technology to conduct radiocarbon dating of animal fat residues found on pottery.

Evershed's research team separated compounds of up to two grams from pottery samples and detected very small traces of fatty acid carbon in milk, cheese and meat residues. The new technology could help reveal the dietary changes of prehistoric creatures.

Evershed's discovery has been listed among the "Top 10 Discoveries of 2020" by Archaeology, an influential journal published by the Archaeological Institute of America.

Diet has always been a subject of great interests in archaeology, as it offers important clues for the study of human development. Research has found that frescoes in a temple in Babylon dating back about 6,000 years are the earliest historical records of humans cultivating and drinking milk. Milk's values are not limited to its nutrients. A closer study of it over the centuries could reveal the change and development of human society and even patterns of global civilizations.

Milk and dairy products were not popular in Europe until the 19th century. As milk was not easy to preserve and was apt to sour it became a breeding ground for bacteria without refrigeration. For that reason milk was once banished as a food for the poor and the rich kept it at a distance.

New technologies changed that. Pasteurization, developed in the mid-19th century, gradually helped milk become a popular consumer good. With the emergence of trains and the advent of refrigerators in the 20th century, milk could be transported and became easier to preserve and gradually more popular worldwide.

Then came a major breakthrough. UHT (ultra high temperature) technology revolutionized milk consumption. In the 1960s, aseptic packaging and UHT treatment pushed the boundaries of sterilized milk processing, significantly expanding the transportation range of milk products while greatly improving their shelf life and safety. In Western European countries, the market share of UHT milk increased from merely 16 percent in 1974 to 54 percent in 2000.

Market acceptance, just like Rome, wasn't built in one day and there have always been doubters and rumors along the way. China, in early days a stranger to UHT, was no exception.

There are still doubters wondering if preservatives were added, given that the storage time of UHT milk can be as long as five to eight months. Those privy to what UHT technology is will realize how unfounded that idea is.

UHT (ultra high temperature) sterilization milk, as the name indicates, involves treating milk at a high temperature (usually at least 135 C or 275 F) for one or two seconds .

UHT technology can basically eliminate bacteria. In a hermetically sealed environment, milk processed in this way can be kept for several months or even longer without refrigeration. Therefore, its safety level is higher as it poses a lower risk of bacteria and microbial toxins.

There are also concerns about UHT milk's nutritional value. Some fear that high temperature will hurt its original nutritional components.