Fat content and fat composition of dairy products
Milk fat content
The milk fat content differs within and between dairy products, see table 1.1 Raw farm milk, full-fat milk, semi skimmed milk and skimmed milk each have their own percentage of fat. Raw milk has an average fat content of 4.4g of milk fat per 100g, and can be skimmed to obtain lower fat varieties. Full-fat milk is standardised to 3.5% of fat and semi skimmed milk contains approximately 1.5% fat. Skimmed milk and buttermilk are very low in fat and, on average, contain 0.1 or 0.2% fat respectively. Due to international differences in standardisation however, the fat percentage for (semi)-skimmed, whole milk and buttermilk can vary according to country.
Table 1: Amounts of fat in dairy products1
|Product||Energy (kcal/100g)||Fat (g/100g)||Saturated fatty acids (g/100g)||Monounsaturated fatty acids (g/100g)||Polyunsaturated fatty acids (g/100g)||Trans fatty acids (g/100g)|
|Milk, full fat||66||3.9||2.5||1.0||0.1||0.1|
|Milk, semi skimmed||46||1.7||1.1||0.4||Tr||0.1|
|Yoghurt, full fat||79||3.0||1.7||0.9||0.2||N|
|Cheese, Gouda 48+ full fat||377||30.6||20.3||7.4||0.9||1.1|
Milk fat composition
Milk fat is composed of a broad range of fatty acids, which makes it one of nature’s most complex fatty acid fractions. More than 200 different fatty acids are naturally present in milk.
- Fat in milk
The actual fat content and composition of milk varies naturally due to several factors, including cow feed composition, which differs in summer and winter, and the amount of time cows spend grazing, as well as intrinsic differences between cows.3 The relatively small amount of fat in milk is quite complex when compared to the fat profile of some major plant fats and oils, even if the major fatty acids are the only ones taken into account, see table 2 for a comparison on the major fatty acids.4
Table 2: Fatty acid composition of milk fat* and a selection of plant oils4
|Food sources||SAFA – short and medium chain length (g/100g)**||SAFA – long chain length (g/100g)***||Monounsaturated fatty acids (g/100g)||Polyunsaturated fatty acids (g/100g)||Trans fatty acids (g/100g) ****|
|Milk – summer*||13||53||26||3||3|
|Milk – winter*||11||60||21||2||2|
|Palm kernel oil||4||75||15||2|
**Short + medium chain SAFA = C4-C10
***Long chain SAFA = C12-C22
****Excludes Conjugated Linoleic Acid, which is 1.3 g (own factory milk – summer) and 0.7 g (own factory milk – winter)
- Milk fat blend
In the milk fat blend, saturated fatty acids make up roughly 60-70% of the total fat content. The remaining 30-40% fats are unsaturated fatty acids, and to a large extent oleic acid, a monounsaturated fatty acid. Milk fat also contains some polyunsaturated omega-6 and omega-3 fatty acids, but these are present only in relatively small quantities. Milk fat generally contains around 1.3% linoleic acid and 0.5% alpha linolenic acid, with concentrations that can increase significantly in spring and summer compared to autumn and winter.3,5 Milk and dairy products also contain small quantities of natural polyunsaturated acids with a trans and a cis binding, which are commonly referred to as conjugated linoleic acid.
- R.A. McCance and E.M. Widdowson, McCance and Widdowson’s The composition of Foods. Sixth summary ed. 2002: Cambridge: Royal Society of Chemistry.
- P. Walstra et. al., Dairy science and technology. 2nd ed. 2006.
- J.M. Heck JM et al., Seasonal variation in the Dutch bovine raw milk composition. J Dairy Sci, 2009. 92(10): p. 4745-55.
- Own data FrieslandCampina, 2007.
- H.J. van Valenberg, et al., Concentrations of n-3 and n-6 fatty acids in Dutch bovine milk fat and their contribution to human dietary intake. J Dairy Sci., 2013. 96(7): p. 4173-81.