Study Finds Different Nutritional Profiles in Chinese and Imported UHT Milk
Researchers bought six Chinese products, five from Western Europe and five from Australia and New Zealand through Jingdong Mall, a Chinese e-commerce platform. They preferentially selected imported products described as grass-fed or pasture-based, while noting that such labels may not capture the cows’ diet over an entire year. Every sample consisted only of raw milk or organic raw milk and was packed in an aseptic carton.
Chinese products generally had more fat and lactose than the imported samples. They also contained the highest measured amounts of vitamin E, vitamin B3, zinc and iodine. Milk from Australia and New Zealand recorded the lowest levels of fat, total solids and vitamin A among the regional groups. The researchers said that processing standardisation might partly account for the relatively high fat and protein levels in the Chinese products. Calcium, phosphorus and magnesium, which are associated with casein micelles, showed no significant regional differences.
The results for fat-soluble vitamins differed from the pattern often associated with pasture feeding. Imported milk had less vitamin A and vitamin E than the domestic Chinese products. The researchers connected this result in part with the longer processing and transport requirements of imported UHT milk, including the need for extended shelf lives and the possibility of greater cumulative heat exposure. Vitamin A can deteriorate during heating, while vitamin E losses may rise with temperature and holding time; both vitamins may also decline during storage. Imported milk had more vitamin B2, a result the researchers associated with the larger contribution of green forage in pasture-based systems. Chinese milk had more vitamin B3, consistent with diets containing more cereal grains and total mixed rations.
The clearest separation concerned polyunsaturated fatty acids. Chinese milk contained more of several omega-6 fatty acids, whereas imported products had more of several omega-3 fatty acids. The measured omega-3-to-omega-6 ratio was about 0.12 in the Chinese samples, compared with roughly 0.31–0.32 in the imported group. The researchers related the difference to feeding systems: pasture and fresh forage provide alpha-linolenic acid, an omega-3 precursor, while maize silage, cereals and oilseeds used in total mixed rations provide more linoleic acid, an omega-6 fatty acid.
Imported products also contained higher concentrations of several short- and medium-chain fatty acids, including C4, C6, C12 and C14. Odd-chain fatty acids, including C11, C15, C17 and C21, were likewise higher and can act as markers associated with pasture-based feeding. The researchers cautioned that choosing imported milk alone would not substantially alter a person’s overall dietary fatty-acid profile because milk and dairy products account for a relatively small share of total food and milk-fat consumption in China.
Eight trained assessors conducted the sensory testing. Imported milk received higher scores for cow-like and tea-like flavours and for astringency, while domestic samples were judged brighter in colour and sweeter. The researchers associated the yellow-cream appearance of pasture-based milk with forage compounds such as carotenoids and riboflavin, and linked the sweeter perception of Chinese milk to its higher lactose content. No significant difference in cooked flavour was found. The authors noted that cultural familiarity may affect sensory assessments, since Chinese assessors may respond differently to pasture-derived characteristics from panels or consumers in Western countries.
Principal component analysis placed the domestic samples closer together, associating them with higher fat, vitamin E and omega-6 fatty acids. Imported products showed more variation and were associated with vitamin B2, omega-3 fatty acids, short- and medium-chain fatty acids, long-chain fatty acids, astringency and tea flavour. The researchers said the variation could reflect differences in feeding systems, processing technologies and storage conditions across Western European and Oceanian dairy industries. They concluded that the two groups should not be judged simply as better or worse. The study called for improved vitamin retention during storage and transport, vitamin A fortification where appropriate, and stronger regulation of grass-fed and pasture-related claims.
