Producing lactose-free dairy products: techniques available
Milk, cheese, and yogurt have been hailed for their calcium content and essential nutrients. But for those suffering from lactose intolerance, that delicious glass of milk can come with a side of discomfort. Thankfully, dairy processing plants are innovating to ensure everyone can get their fill of calcium and creamy goodness.
What is lactose intolerance?
Lactose is a natural sugar found in milk and dairy products. Our bodies break down lactose using an enzyme called lactase, which breaks lactose into glucose and galactose. These monosaccharides are easily absorbed in the small intestine and prevent the occurrence of lactose intolerance symptoms. Children are born with the ability to produce lactase, but as people get older, the production of lactase reduces or even stops. People with lactose intolerance have insufficient lactase production, and lactose reaches the large intestine undigested, leading to digestive discomfort like bloating, gas, diarrhea, and cramps after consuming dairy.
The percentage of people suffering from lactose intolerance varies widely per country and per continent. However, the lactose-free dairy market is the fastest-growing segment in the dairy industry. For 2024, the sales of lactose-free dairy products are valued at $13.87 billion and expected to grow by 5.8 percent by 2034 (1).
How is lactose-free milk produced?
For the market, the lactose-free liquid milk segment retains the largest share of the market compared to cheese, yogurt, or other dairy products. There are two techniques used to produce lactose-free milk. The main technique is to add the missing enzyme, lactase, into the milk. The enzyme used has been the neutral β-galactosidase, which is produced by various companies. In general, the process of adding the enzyme is different depending on the product. The process of adding the enzyme for pasteurized milk stored under cooled conditions, mostly in the U.S. and European markets, is different from UHT sterilized milk marketed in other countries, such as in Central and South Africa and in Asian countries. The batch process is used for pasteurized milk, while the aseptic process is used for UHT milk.
In the batch process, lactase is added to a tank of raw milk and incubated for 24 hours. As it is raw, non-sterile milk, the process must be performed at a low temperature (4-8oC) to prevent the growth of microbes. Then, after the incubation, milk is pasteurized, homogenized, and packaged. As the enzyme is inactivated at high temperature during pasteurization or sterilization, in the aseptic process, the enzyme is added after the milk is sterilized in aseptic conditions, usually before packaging.
For yogurt and cheese production, lactose-free milkproduced from the batch process can be used to produce these dairy products. However, the enzyme can be added at the same time as the yogurt culture during the yogurt-making process. The drawback of this technique is that the most neutral lactases are inactivated at a low pH, which is reached after a couple hours of incubation. Therefore, it requires a relatively high lactase dosage to obtain lactose-free products.
Another method is to use ultrafiltration, which removes the lactose from milk. The filter process pulls out lactose, fat, or protein from the milk as it passes through the filter. Once separated, protein and fat are added back to the milk. The filtration technique can be used by adding lactase to remove the remaining lactose.
It is important to note that clear labeling and providing clear information about ingredients, nutritional value, and potential allergens are crucial for consumers to be informed.
