Lactase

Lactase is the food-industry name for beta-galactosidase (EC 3.2.1.23, CAS 9031-11-2), systematically beta-D-galactoside galactohydrolase. It catalyses the hydrolysis of terminal non-reducing beta-D-galactose residues in beta-D-galactosides, which in practice means splitting the disaccharide lactose into D-glucose and D-galactose. The human intestinal enzyme, lactase-phlorizin hydrolase, is separately numbered EC 3.2.1.108 and EC 3.2.1.62; the commercial article supplied for food and supplement use is the microbial beta-galactosidase, and specifications should quote EC 3.2.1.23 to avoid confusion between the two. Because glucose and galactose are both sweeter than lactose, hydrolysis also raises perceived sweetness in a dairy base, which is a useful food-technology consequence in frozen desserts and flavoured milks. Two source families are supplied and the choice is not interchangeable. Acid lactase is produced by fermentation of Aspergillus oryzae or A. niger and works in the low-pH range, which suits dry supplement formats. Neutral lactase is produced from the yeasts Kluyveromyces lactis or K. fragilis and works at dairy pH, which suits in-process hydrolysis of milk and whey. The commercially critical point is allergen origin: Kluyveromyces lactase is propagated on lactose or whey media and must be declared as containing MILK, whereas Aspergillus-derived acid lactase is produced without dairy substrate and is vegan-suitable. Getting this the wrong way round on a finished label is a recall risk, so Thovek fixes the source at order, names it on the certificate of analysis and issues a written allergen statement per lot. Activity, not protein content, is what is specified. It is reported per lot in FCC acid lactase units (ALU) for fungal grades or in neutral lactase units for yeast grades, with one enzyme unit (U) defined as one micromole of substrate converted per minute; the SI katal, one mole per second, is too large for labelling. Powder is standardised with maltodextrin or dicalcium phosphate and the carrier is named on the CoA. Tablets are supplied uncoated to an agreed weight, activity and dimension, typically using microcrystalline cellulose, croscarmellose sodium and vegetable-source magnesium stearate — the stearate origin is stated in writing so a vegan claim can be substantiated rather than assumed, since magnesium stearate is also available from bovine tallow. Material is offered against the Enzyme Preparations family monograph of the Food Chemicals Codex published by USP, with purity and microbiological results on the certificate of analysis. Thovek describes composition and established food-technology function only, and makes no therapeutic or disease claim.