COMPOSITION
Vitamin D, a fat-soluble vitamin that enhances the intestinal absorption of calcium and phosphorus, is essential for the maintenance of a healthy skeleton throughout life. Vitamin D is present in low concentrations in South African milk as it is unfortified, but exposure to sunlight should provide adequate vitamin D for most people living in South Africa.
| Dairy alternatives are generally derived from plant based ingredients such as soya, rice, almond, oat, coconut, hazelnut or hemp. While they are sometimes used as a replacement for cow’s milk, they are not nutritionally equivalent. The main difference is that the dairy alternatives are often fortified with calcium and vitamin B12, while dairy milk is a natural source of calcium and a rich matrix of other micronutrients (including riboflavin, vitamin B12, iodine, potassium and phosphorus). Dairy milk is naturally higher in good quality protein at about 3.5 %. The alternatives are generally around 0.5 % protein, with the exception of soya at around 3 %. Some alternatives have added sugar, while milk contains lactose, a natural sugar. Soy milk is the best source of protein of the non-dairy options. It does not naturally contain calcium and vitamin B12, but is often fortified with these nutrients. Rice milk is much lower in protein and could be fortified with calcium, and vitamins D and B12. Oat milk is naturally sweet and more palatable non-dairy milk options. Often sugar is added and this beverage contains very little protein (less than 1 gram per glass). Almond milk is made out of ground almonds with water. This non-dairy drink is very low in protein with just 1 g per glass, but may have more calcium than dairy milk, along with vitamins D and E. Hemp milk is made of hemp seeds, which are high in heart-healthy omega-3 fatty acids. It also has some protein but falls short in calcium. Coconut milk has little protein and about the same saturated fat as whole milk — about 4 grams in a cup. |
Flavoured milk is a pasteurised and homogenised low fat dairy milk product that is coloured, sweetened and flavoured. It then undergoes a sterilisation process which removes all micro organisms and helps to extend its shelf life. This product can be kept on shelf for longer than regular dairy beverages.
Raw milk can contain harmful bacteria and therefore, the consumption of raw (unpasteurised) milk increases the risk of developing foodborne illness. Pasteurisation is an important and well-established food safety measure, which is practiced globally. It is a simple heating process which usually involves heating milk at 72°C for 15 seconds to destroy any harmful micro-organisms.
Not all milk is pasteurised but it is illegal to sell raw milk in South Africa for direct use unless the specific municipality where the sale is taking place is authorised to do so in terms of the law (R1510). Even then, raw milk should be dealt with cautiously and rather be properly heated prior to use.10
Appropriate heat treatment limits harmful bacteria that may be present in food and ensures that the food is safe for consumption. Milk can be heat treated through four different methods. Pasteurisation involves heating milk to a high temperature (72°C), followed by a rapid cooling to 4°C. Ultra-pasteurisation involves treatment at a higher temperature and claims a shelf life of more than 14 days if kept at 4°C or lower. Ultra-high temperature treatment involves heating milk to between 135°C and 150°C for up to two to four seconds and then cooling it to 4°C or lower. This treatment is used to produce long-life milk with an extended shelf life. Sterilization involves heating of bottled milk to 110°C to 130°C for 10 to 30 minutes after which the bottles are cooled. Unopened bottles of sterilized milk keep for a long time without the need for refrigeration.
Fortified milk is milk that has been enriched with specific nutrients. The nutrients that are added are often based on population insufficiencies and often tailored for specific consumer categories e.g. folic acid, vitamin D, iron, protein.
Organic farming is a system of farming which avoids the use of soluble fertilisers, pesticides, feed additives and other chemicals. Most of the nutritional differences are small and related to the pasture grazing of organic cows. Organic milk usually contains higher amounts of omega-3 fatty acids, although the absolute amount is still quite low. Therefore, this may have little effect in the context of an individual’s overall diet. Organic milk also contains about a third less iodine compared to regular milk. Iodine is an important nutrient that contributes to cognitive function and is therefore particularly important for pregnant women.
Raw milk defined in terms of national health legislation means milk that has not undergone pasteurization, sterilization or ultra-high temperature treatment. Raw milk for direct consumption is generally considered to be of higher risk due to its potential as a carrier of harmful bacteria not normally associated with pasteurized milk. The general convention is that while the milk is in the production system of a healthy cow it is considered to be virtually sterile.