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Dairy alternatives are generally derived from plant-based ingredients such as soya, rice, almond, oats, 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 dairy alternatives are often fortified with calcium and vitamin B12, whereas dairy milk is a natural source of calcium and has a rich matrix of other micronutrients (including riboflavin B2, vitamin B12, iodine, potassium and phosphorus).
- Cow’s milk also naturally contains about 3.5% good-quality protein, whereas dairy alternatives generally have a protein content of around 0.5% (this excludes soy milk, which contains about 3% protein).
- Some dairy alternatives contain added sugar, whereas milk contains lactose, a natural sugar.
Flavoured milk is a pasteurised and homogenised low-fat dairy milk product that is coloured, sweetened and flavoured. It is then sterilised to remove all microorganisms. The process also helps to extend its shelf life (flavoured milk can be kept on the shelf for longer than regular dairy drinks).
Fermented milk products, also referred to as cultured milk products, are produced by adding bacterial cultures (usually lactic acid bacteria), yeast or mould to milk. During fermentation, lactose (the sugar that naturally occurs in milk) is converted to lactic acid. This causes gelatinisation, which thickens the milk. Examples of fermented milk products include yoghurt, kefir, maas, sour cream and crème fraîche.
Fermented dairy products may have additional health effects owing to their lower pH than normal milk. The higher acidity affects the rate at which the stomach is emptied and thereby reduces the glycaemic response (i.e. the effect on blood sugar). Beneficial effects may also be due to bio-active peptides present in fermented dairy. These substances have been linked to lowering blood pressure and countering low-grade inflammation (evident in obesity).
Functional foods are an emerging food category, generally regarded as foods that may provide additional health benefits following the addition or concentration of a beneficial ingredient, or the removal or substitution of a harmful ingredient. Dairy foods such as milk, yoghurt and spreads are often used as carriers for functional ingredients. An example of a dairy-based functional food is a yoghurt drink with added plant sterols or stanols, which have been clinically proven to lower cholesterol. Any health claims shown on the label of a functional food product has to be in line with regulations issued by the South African Department of Agriculture, Forestry and Fisheries.
These ruminant animals release methane as a by-product of digestion of food in the rumen and large intestine. This process, called enteric fermentation, produces more than half of all greenhouse gas emissions from agriculture. Methane emissions from livestock depend on a number of factors, in particular livestock type, diet quality and feed intake. Research into the utilisation of this methane for energy production and the reduction of methane emissions by the dairy sector is ongoing.