What is designer milk?
Milk can be designed to suit the needs of the consumers by suitably modifying its composition through nutritional interventions or transgenic methods. Designer milk is simply tailor made to provide the dual advantage of processing and health benefits to the consumers.
In an era where market is governed by customized commodities to meet the demands of the customers, designer milk satiates the palates of the consumers with more controlled and regulated supply of nutrients in the form of less fat and more protein. The need to search for customized milk called “designer milk” becomes more pertinent in the light of important role played by milk and dairy products. Milk and dairy products universally attract new born, kids, adolescents, adults and elderly alike.
To define, designer milk is nutritionally or genetically modified milk tailor made to consumer preferences, rich or poor, in specific milk components that offer the consumer greater health benefits. This novel initiative is possible because of the developments in genetic engineering and dairy biotechnology.
What is new in designer milk from the dietary and health point of view?
- To increase the proportion of unsaturated fatty acids in milk and thereby lowering the risk of cardiovascular diseases, especially, for the obese middle aged and elderly people.
To reduce lactose content of milk, thus paving the way for better acceptance by lactose intolerant persons.
To remove the beta lactoglobulin from milk which is sometimes associated with allergy in children.
The novelty from the technological angle
- Altering the primary structure of casein to improve technological properties of milk
Engineering milk in such a way that results in accelerated curd ripening and better yield during the cheese making process.
Milk with the much needed high protein content
- Nutraceutical milk containing human therapeutic proteins
- A suitable replacement for infant milk formula.
What is modified in the milk to make it designer?
There are two methods viz. nutritional interventions and transgenic animals by which the fat, protein and lactose content of the milk can be altered.
The result can be achieved by suitably altering the feeding pattern of the dairy cows.
Milk fat : In general, milk contains 3 to 4% milk fat. The majority of the fatty acids in milk are saturated with 4 to 18 carbon atoms (short chain). The rest are mono unsaturated (16:1 and 18:1) and ploy unsaturated (18:2 and 18:3). From the saturation point of view, milk contains 70% saturated fatty acids, 25% mono-unsaturated and 5% poly-unsaturated fatty acids.
Majority of the dairy scientists are of the opinion that the ideal milk shall contain less than 10% poly-unsaturated fatty acids, less than 8% saturated fatty acids and more than 82% mono-unsaturated fatty acids. The modification of milk fat can be achieved by decreasing the level of saturated fatty acids, increasing the level of conjugated linoleic acid content and increasing the omega 3 fatty acids in milk.
Saturated fatty acids: They are often accused as culprits associated with heart diseases because of their ability to the blood cholesterol. But not all the saturated fatty acids are bad. The fatty acids with less than 12 carbon atoms, in fact, decrease the cholesterol content since they are all catabolised. The real culprits are Lauric (C12:0), Myristic (C14:0) and Palmitic (C16:0) which increase the plasma concentration of cholesterol. Their share is 44% in the total milk fatty acids.
Feeding of dairy cows with unsaturated fats in protected form through encapsulation increases the unsaturated fat content in milk. However, the unsaturated fatty acids are converted into saturated one in the rumen by the rumen microorganisms. To prevent this, rumen by pass is the only way out. This can be achieved when small droplets of lipids are encapsulated in thin layer of protein through formaldehyde treatment and fed to the dairy cows. Doubling the spreadability of butter is achieved when a special blend of canola and soy bean meal in protected form is fed to dairy cows because the melting point of milk fat containing unsaturated fatty acid is higher.
How to increase the Conjugated Linoleic Acid (CLA) content in milk?
CLA is a product synthesized in rumen due to bio-hydrogenation of linoleic acid. The bio-hydrogenation adds hydrogen atoms to unsaturated fatty acids. The cis-9, trans-11 is the most common isomer in ruminant products and accounts for more than 90% of the CLA in milk. A diet rich in linoleic and linolenic acids in the form of oil / seeds increases the CLA levels in milk fat two fold when oil is accessible to the rumen microorganisms for bio-hydrogenation. Milk from grass fed animals is known to contain five times higher CLA level than those fed with grain.