Protease

Protease is the collective name for the peptide hydrolases of EC class 3.4 — the enzymes that cleave the peptide bonds holding a protein chain together, releasing shorter peptides and free amino acids. The class is divided by catalytic mechanism into serine, cysteine, aspartic, threonine, metallo and glutamic peptidases. Commercial digestive-enzyme protease is drawn from four practical sources: fermentation of Aspergillus oryzae or A. niger; bacterial fermentation of Bacillus species yielding subtilisin (EC 3.4.21.62, CAS 9014-01-1); papain from the latex of Carica papaya (EC 3.4.22.2, CAS 9001-73-4); and bromelain from pineapple, Ananas comosus, as stem bromelain (EC 3.4.22.32, CAS 37189-34-7) or fruit bromelain (EC 3.4.22.33, CAS 9001-00-7). Because the name covers a class and not one molecule, there is no single CAS number for "protease" — the specification must always name the source organism or plant and the assay used. Thovek supplies protease as a free-flowing powder standardised to a declared activity rather than to a protein percentage, because activity is what a formulator actually buys. Acid, neutral and alkaline-active types differ in the pH window in which they work, which matters when a blend has to function across the pH range of a meal or a food process, and the type is fixed at order. Activity is reported per lot in the FCC assay unit appropriate to that type — the HUT, SAPU and PC unit systems are the ones normally quoted for proteases. One enzyme unit (U) corresponds to one micromole of substrate converted per minute; the SI equivalent, the katal, is one mole per second and is far too large for practical labelling. Standardisation to the ordered activity is carried out with maltodextrin or dicalcium phosphate, and the carrier actually used is named on the certificate of analysis so it can be transferred into the buyer's own declaration. Origin and allergen status are declared in writing on every lot, because a wrong declaration is a recall risk downstream. Microbial protease is vegan and vegetarian, with no bovine, porcine, marine, egg or dairy input at any stage. However, fungal and bacterial fermentations are frequently run on wheat bran, rice bran or soy-derived nutrients, so gluten and soy are tested and declared per lot rather than assumed. Papain and bromelain are plant enzymes free of milk, egg, soy, fish, crustacean, gluten and tree nut, though papaya and pineapple must appear in the buyer's ingredient declaration. Proteolytic enzyme dust is a well-documented occupational respiratory sensitiser, so blending operations should use local exhaust ventilation and appropriate personal protective equipment. 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 claim.