Lactose in Foods and Pharmaceuticals

Lactose is one of the most commonly used materials in a number of industries, and has major applications in the food and pharmaceutical manufacturing. The physical properties of lactose are such that enable it to function in a wide variety of applications. For instance, its widespread use in pharmaceutical dosage forms arises from the absence of any real toxicity or unacceptable taste, its favourable mechanical qualities, and good aqueous solubility.

When utilized as a food ingredient to provide functional value, lactose can be applied in diverse food products including bakery goods, confections, dry mixes, dairy foods, dried vegetables, snacks, and infant formula. For example, lactose can be used in bakery goods for enhancing browning and reducing sweetness. In addition, lactose may be used to partially replace skim milk powder in some baked products, such as muffins and biscuits, without significantly affecting product quality yet providing an effective means of cost reduction. In the confection area, a portion of skim milk powder and sugar are commonly substituted by lactose in milk chocolate. Lactose is also commonly applied in dried vegetable process in order to reduce sweetness and prevent discolouration. Dried vegetable processed with 3% lactose had better appearance and colour after rehydration. Due to lactose having no flavour and being relatively less sweet, it is commonly used as a filler and flowing agent in seasoning mix, such as instant noodle soup mixes. It is also an excellent carrier for flavours and seasonings.

Whey in Foods

Whey protein ingredients are protein-enriched fractions that range in protein content from 25% to over 90%. They function in food by contributing structural, stability, nutritional and nutraceutical properties. These properties can be enhanced by several approaches. The simplest way is to alter the amount and/or composition the non-protein components. Whey protein concentrates that contain 35% protein also contain 51 to 54% lactose; in contrast to whey protein isolate with over 90% protein and 1% or less lactose. Whey contains several proteins (beta-lactoglobulin, alpha-lactalbumin, glycomacropeptide, bovine serum albumin, immunoglobulins, lactoferrin and lactoperoxidase) that can be enriched or isolated for specific functional applications. These proteins can also be enzymatically or chemically modified to alter functionality.

Whey can be used in food products in a variety of forms. Dried whey is one of the least expensive sources of solids that can be used in food. Dried whey can contribute a slight dairy of fermented flavour and serves as a source of reducing sugars. The protein content is very low and little functionality can be expected. The majority of whey used in food applications is in the form of whey protein concentrates (WPC). WPC 34 with 34% solids can be used in a number of applications to replace non-fat dried milk. The protein is all whey rather than mostly casein and is not as functional when thermal stability is required. It is capable of forming gels and is good at emulsification and foaming. It finds many applications in dried mixes, in fillings and in sauces. There has been an explosive increase in WPC products that contain 80% or more protein. Initially the main use of these ingredients was in applications that required high gel strength. They are also functional in sterile nutritional products where they function well as emulsifiers and help to retard long-term gravitational creaming. Whey protein isolates contain at least 90% protein and can be produced either by ion exchange or by a combination of microfiltration and diafiltration. These products are extremely low in lipid and are very clear in solution. Their main application is in fluid nutritional beverages.

Lactose vs Fat

With a lactose content of 52 per cent in skim-milk powder, one may realise how dangerous the current fad is for using low-fat ice-cream, yoghurt, cottage cheese etc., instead of full-fat products. Such low-fat foods are made from skim-milk powder and contain 3 to 5 times as much lactose as the equivalent full-fat foods. Sometimes skim-milk powder is even added to butter. Therefore one should read the label and avoid butter that lists 'non-fat milk solids' as one of the ingredients.

Skim-milk powder is also a favourite additive to many other commercial foods, such as bread and other baking products, sausages and margarine. The health-food industry is equally fond of adding lactose to many. Lactose is often used as a filler in white tablets. Cell salts are almost pure lactose. One should try avoiding white tablets if the label does not state that they are free of lactose or are low-allergy tablets.

Skimmed milk also contains more lactose than whole milk. As a general rule, the thicker the milk the less is its lactose content. As for Cheese, the older and maturer the cheese is, the less lactose it contains. Some very mature cheeses, such as parmagian may contain no lactose at all.

Quick checklist for milk products

The products in the table below contain milk or any of its components. Always check the ingredients label.

A detailed list of food products derived from milk.

Products marked with a "*" may not necessary have derived or contain from milk. This depends on the manufacturer.