Lactose-free milk : lactose intolerance, nutrition and process technology

Abstract: The inability to properly digest lactose into its constituent’s glucose and galactose, is prevalent worldwide, thus affecting large groups of people, who cannot benefit from the nutritional aspects of consuming dairy products. To enable consumption of dairy products even in adult individuals which suffer from lactase deficiency, the dairy industry has further developed dairy technologies. This has resulted in a growing assortment of the lactose-free dairy products available to the consumer. The aim of this literature review was to compile current processing methods used in the separation and the hydrolysis of lactose present in bovine milk, as well as to discuss the advantages and disadvantages of these methods. Firstly, lactose intolerance is presented. Then the definition of lactase and different types of lactase deficiencies are given. Thereafter, the worldwide prevalence of lactase persistence and effects on nutritional intake is discussed. Finally, the review is identifying and mapping the principal process technologies available in production of lactose-free and lactose reduced milk, along with a discussion of factors to consider in the process technologies for milk. In conclusion, there are methods and processes available on the market, which enables production of lactose-free/lactose reduced milk to the consumers. Most new industrial processes for production of lactose-free dairy products rely on the membrane separation techniques, followed by enzymatic hydrolysis of lactose residues. In the future, these processes are likely to continue to develop, which may result in the introduction of new products to the consumer market.