The Lact Unit (LU) is a standardized measure of lactase enzyme activity. This unit quantifies the ability of a lactase preparation to break down lactose, the main sugar found in milk. The standard most commonly used in the food and supplement industry is the Food Chemical Codex (FCC) Lactase Unit, often abbreviated as FCC LU or FCC ALU (Acid Lactase Unit). This standardization provides a global benchmark, allowing manufacturers, producers, and consumers to accurately compare the functional potency of different enzyme products.
The Core Function of Lactase
Lactase is a digestive enzyme naturally produced by cells lining the small intestine. Its primary role is to process lactose, a disaccharide made up of one molecule of glucose bonded to one molecule of galactose.
The lactase enzyme performs a hydrolysis reaction, using water to break this chemical bond. This action separates lactose into the smaller, simple sugars glucose and galactose, which are then absorbed into the bloodstream.
This breakdown is necessary for the body to utilize the energy from milk sugar. If the body does not produce enough lactase, undigested lactose moves to the large intestine, where gut bacteria ferment the sugar, causing digestive discomfort.
Lact Units in Dietary Supplements
The Lact Unit is the standard measure consumers rely on when purchasing over-the-counter lactase supplements. Supplement potency is nearly always expressed in FCC units, which indicates the enzyme’s activity in the acidic environment of the stomach. The FCC unit provides a practical guide for determining the correct dosage to alleviate symptoms of lactose intolerance.
Most individuals find relief with a dosage ranging from 3,000 to 9,000 FCC units per serving, taken just before consuming dairy products. A common guideline suggests 1,000 FCC units are needed to process about 5 grams of lactose. Since an eight-ounce glass of milk contains 12 to 13 grams of lactose, a large dairy meal might require a higher dose, such as a 9,000 FCC unit tablet.
Consumers can adjust their intake based on the estimated lactose content of their meal and their personal degree of intolerance. The standardization provided by the FCC LU ensures that products labeled with the same unit count offer comparable enzyme activity, allowing users to effectively manage their discomfort.
Lact Units in Commercial Food Processing
In the food industry, the Lact Unit is used to manufacture lactose-reduced and lactose-free dairy items like milk, ice cream, and yogurt. Manufacturers purchase purified lactase, often derived from fungi, with potency guaranteed by the supplier using the FCC LU standard. This measurement is crucial for quality control, ensuring every production run achieves the required reduction in lactose content.
The process involves adding a calculated amount of the enzyme preparation to the milk, often before pasteurization. The amount added, based on its FCC LU rating, determines the rate at which lactose is hydrolyzed into glucose and galactose. Producers aim to reduce the lactose content to less than 0.01% to legally market the product as lactose-free.
The predictable activity quantified by the Lact Unit allows processors to control reaction time and temperature to consistently meet this regulatory threshold. For instance, a manufacturer might use a specific amount of liquid enzyme rated at 5,000 FCC LU per milliliter to treat a large volume of milk over a set period. The FCC LU ensures the enzyme’s reliable performance, which is necessary for maintaining consistent product quality.