A new study published in Food Science of Animal Resources has found significant differences in the nutritional composition, fatty acid profiles and sensory characteristics of commercial UHT milk sold in China. The research compared 16 whole-milk UHT products from China, Western Europe, Australia and New Zealand, highlighting how cow diets, production systems, processing and transportation can influence the characteristics of milk reaching consumers.
The researchers purchased six Chinese, five Western European and five Australian and New Zealand milk products from the Chinese e-commerce platform Jingdong Mall. Imported products labelled as grass-fed or pasture-based were preferentially selected, although the researchers noted that such labels do not necessarily represent the complete annual diet of the cows.
All samples contained only raw milk or organic raw milk without additives and were packaged in aseptic cartons.
Differences in Milk Composition
The study found that domestic Chinese milk generally contained higher levels of fat and lactose than imported products. Chinese samples also recorded the highest levels of vitamin E, vitamin B3, zinc and iodine.
Meanwhile, milk from Australia and New Zealand showed the lowest levels of fat, total solids and vitamin A among the groups studied.
The researchers suggested that the relatively high fat and protein levels found in Chinese products may partly reflect standardization practices used during dairy processing. Minerals associated with casein micelles, including calcium, phosphorus and magnesium, did not show significant differences between the regional groups.
Processing Influences Vitamin Levels
One of the study’s notable findings involved fat-soluble vitamins. Although pasture-based feeding is commonly associated with higher levels of certain nutrients, imported milk had lower vitamin A and vitamin E levels than domestic Chinese products.
The researchers linked this finding partly to the greater processing and transportation requirements associated with imported UHT milk. Longer supply chains can require longer shelf-life periods and may expose products to greater cumulative heat loads.
Vitamin A can degrade during thermal processing, while vitamin E losses can increase with temperature and holding time. The study also referenced evidence that these vitamins can continue to decline during storage.
Imported milk, however, contained higher levels of vitamin B2. The researchers associated this pattern with the greater contribution of green forage to pasture-based feeding systems. Chinese milk recorded higher vitamin B3 levels, which is consistent with diets containing more cereal grains and total mixed rations.
Clear Differences in Omega-3 and Omega-6 Fatty Acids
The strongest nutritional separation between domestic and imported products appeared in their polyunsaturated fatty acid profiles.
Chinese milk contained higher concentrations of several omega-6 fatty acids, while imported samples had higher levels of several omega-3 fatty acids. The measured omega-3-to-omega-6 ratio was approximately 0.31–0.32 in imported milk, compared with 0.12 in Chinese samples.
The researchers linked these differences to cattle feeding systems. Pasture and fresh forage are rich sources of alpha-linolenic acid, an omega-3 precursor. By comparison, maize silage, cereals and oilseeds commonly used in total mixed rations provide greater amounts of linoleic acid, an omega-6 fatty acid.
Imported milk also contained higher concentrations of several short- and medium-chain fatty acids, including C4, C6, C12 and C14. Odd-chain fatty acids such as C11, C15, C17 and C21 were also elevated in imported products and can serve as indicators associated with pasture-based feeding.
However, the researchers cautioned that choosing imported milk alone would not substantially change an individual’s overall dietary fatty acid profile. Milk and dairy products represent only a relatively small share of total food and milk-fat consumption in China.
Sensory Characteristics Also Differed
The research included sensory testing by eight trained assessors. Imported milks received higher scores for cowy and tea-like flavours and astringency, while domestic samples were perceived as brighter in colour and sweeter.
The researchers associated the yellow-cream appearance of pasture-based milk with compounds such as carotenoids and riboflavin present in forage. The sweeter perception of domestic milk was consistent with its higher measured lactose content.
Despite differences in processing and storage, the study found no significant difference in cooked flavour between domestic and imported milk.
The authors also acknowledged that sensory results can be influenced by cultural familiarity. Chinese assessors may perceive pasture-derived milk characteristics differently from consumers or trained panels in Western countries.
Research Shows Two Distinct Production Profiles
Principal component analysis further separated domestic and imported samples. Domestic milk samples clustered more closely and were associated with higher fat, vitamin E and omega-6 fatty acids.
Imported products showed greater 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 suggested that this greater variation among imported products may reflect differences in feeding systems, processing technologies and storage conditions across Western European and Oceanian dairy industries.
Key Findings
| Characteristic | Chinese Milk | Imported Milk |
|---|---|---|
| Fat | Higher | Lower |
| Lactose | Higher | Lower |
| Vitamin E | Higher | Lower |
| Vitamin B3 | Higher | Lower |
| Vitamin A | Higher | Lower |
| Vitamin B2 | Lower | Higher |
| Omega-6 fatty acids | Higher | Lower |
| Omega-3 fatty acids | Lower | Higher |
| Omega-3/Omega-6 ratio | Approx. 0.12 | Approx. 0.31–0.32 |
| Short-chain fatty acids | Lower | Higher |
| Pasture-related fatty acid markers | Lower | Higher |
| Sweetness perception | Higher | Lower |
| Cowy and tea flavours | Lower | Higher |
The researchers concluded that domestic and imported milk should not simply be viewed through a better-versus-worse comparison. Instead, their nutritional and sensory differences reflect distinct agricultural and processing systems.
The study also highlighted relatively low average dairy consumption among Chinese adults and called for measures including improved vitamin retention during storage and transportation, vitamin A fortification where appropriate, and stronger regulation of grass-fed and pasture-related milk claims.
For consumers, the findings demonstrate that the nutritional profile of UHT milk can be influenced by much more than its country of origin. Cow nutrition, farming practices, processing conditions, storage and transportation all contribute to the final characteristics of the product.