Activity units, enzyme classes, probiotic terms and quality documents — explained in plain English for formulators, buyers and QA teams.
Enzymes are sold by activity, not by weight. The unit tells you which assay was used — two products are only comparable when they are measured with the same method.
The amount of enzyme that converts 1 micromole (µmol) of substrate per minute under the stated assay conditions (substrate, pH, temperature). Because conditions differ between methods, a "U" from one supplier is not automatically equal to a "U" from another.
The enzyme unit as standardised by the International Union of Biochemistry: 1 µmol of substrate converted per minute under defined conditions. In practice IU and U are often used interchangeably.
The SI unit of catalytic activity: the amount of enzyme that converts 1 mole of substrate per second. 1 U = 1/60 µmol/s ≈ 16.67 nanokatal (nkat).
Activity per gram or per milligram of product. 1 U/mg = 1,000 U/g. Always check which one a data sheet uses before comparing prices or doses.
Convert units in the calculator →Sandstedt–Kneen–Blish unit for fungal alpha-amylase. One SKB unit dextrinises 1 g of soluble starch per hour at 30 °C in the presence of excess beta-amylase. Common in baking and flour correction.
Fungal amylase →Activity unit for bacterial alpha-amylase, based on the rate at which the enzyme dextrinises starch under the Food Chemicals Codex assay conditions. Used for liquefaction in starch, brewing and baking.
Protease unit used mainly for bromelain and papain. One GDU liberates 1 mg of amino nitrogen from a standard gelatin solution after 20 minutes at 45 °C and pH 4.5.
Protease activity measured on a haemoglobin substrate at acidic pH (4.7). It is the usual unit for acid (fungal) proteases in food, brewing and digestive formulations.
Activity unit for neutral bacterial protease, measured on a casein substrate at near-neutral pH according to the Food Chemicals Codex method.
A protease unit based on the amount of tyrosine-equivalent peptides released from casein per minute. Often used to express papain activity (TU/mg).
Activity unit defined by the Fédération Internationale Pharmaceutique and used in pharmacopoeial assays — for example lipase, amylase and protease activity of pancreatin. Common on pharmaceutical-grade enzyme specifications.
Lactase activity measured with the synthetic substrate o-nitrophenyl-β-D-galactopyranoside (ONPG) at acidic pH (4.5) and 37 °C. Typical for fungal lactase used in supplements and acidic dairy.
Lactase →Strength of rennet and coagulants, determined by comparing the clotting time of a standard milk substrate against a reference standard (ISO 11815 / IDF 157).
Rennet →Carbohydrase units usually based on the reducing sugar released per minute from xylan (XU), beta-glucan (BGU) or polygalacturonic acid (PGU). Definitions vary between suppliers, so compare products using the same method or a side-by-side trial.
Cellulase activity, typically measured as reducing sugar released per minute from a cellulose substrate such as carboxymethyl cellulose (CMC). Check the data sheet for the exact substrate and conditions.
Activity of alpha-galactosidase, the enzyme that breaks down raffinose-family sugars in beans and legumes, measured on a synthetic p-nitrophenyl substrate.
Activity of maltogenic amylase, the anti-staling enzyme in bread, based on the rate of maltotriose breakdown under standard conditions.
The number of viable microbial cells able to grow into a colony on a plate. Probiotic potency is stated in CFU per gram — for example "100 BN" means 100 billion CFU/g.
Probiotic strains →Shorthand used on probiotic specifications: 1 BN = 1 × 10⁹ CFU per gram of powder. Finished products are usually formulated with an overage so the label count is still met at the end of shelf life.
Every enzyme has an EC (Enzyme Commission) number that starts with one of seven classes, describing the type of reaction it catalyses.
A four-part code (e.g. EC 3.2.1.1 for alpha-amylase) assigned by the International Union of Biochemistry and Molecular Biology. The first digit is the class; the next digits narrow down the bond and substrate.
Catalyse oxidation–reduction reactions. Examples: glucose oxidase (dough strengthening, textile bleaching), laccase (juice stabilisation, denim finishing) and catalase (peroxide removal).
Move a functional group from one molecule to another. Transglutaminase, which cross-links proteins to improve texture in meat, fish and dairy, belongs here.
Transglutaminase →Break bonds by adding water. The largest industrial group: proteases, amylases, cellulases, xylanases, lipases, phytases and lactase are all hydrolases.
Break bonds without water or oxidation, often forming a double bond. Pectate lyases used in fruit processing and bio-scouring are examples.
Rearrange atoms within a molecule. Glucose isomerase, used to make high-fructose syrups, is the best-known industrial example.
Join two molecules using energy from ATP. Mainly important in molecular biology rather than bulk industrial processing.
The newest class (added in 2018): enzymes that move ions or molecules across membranes.
The enzymes you will meet most often in pharma, food, feed and industrial processing — and what each one does.
Breaks proteins into peptides and amino acids. Classified by pH optimum as acid, neutral or alkaline. Used in digestive formulations, protein hydrolysates, meat tenderising, detergents (protein stains) and leather (soaking, bating).
All proteases →Breaks down starch. Alpha-amylase cuts starch chains at random (liquefaction); beta-amylase and glucoamylase release maltose or glucose from the ends (saccharification). Used in starch, brewing, baking, textiles (desizing) and digestive aids.
All amylases →Releases glucose from the ends of starch and dextrin chains. The key saccharifying enzyme in glucose syrup and alcohol production, and a fermentation aid in baking.
Breaks down cellulose. Acid and neutral cellulases are used for juice extraction, feed digestibility and textile bio-polishing (removing fuzz and pills from cotton).
Textile enzymes →Breaks down xylan (hemicellulose) in cereal cell walls. Improves dough handling and volume in baking, lowers viscosity in brewing, and improves nutrient availability in poultry and swine feed.
Breaks down beta-glucans from barley and oats, reducing viscosity in brewing and in feed for poultry and swine.
Degrades mannans found in soybean meal, copra and palm kernel meal, improving the feeding value of these ingredients.
A group of enzymes (polygalacturonase, pectin lyase, pectin esterase) that break down pectin. Raises juice yield and clarity and is used in bio-scouring of cotton.
Breaks fats into fatty acids and glycerol. Used for flavour development in dairy, dough conditioning in baking, fat-stain removal in detergents, degreasing in leather and fat digestion in feed.
Acts on phospholipids. Used to strengthen dough, in egg-yolk processing and in oil degumming.
Releases phosphorus locked in phytate in plant-based feed, so less inorganic phosphate has to be added and less phosphorus ends up in manure.
Feed enzymes →Splits lactose into glucose and galactose. Used for lactose-free dairy and in digestive supplements for people with lactose intolerance.
Breaks down raffinose and stachyose, the sugars in beans and legumes that can cause gas, in food and supplement applications.
Forms bonds between proteins, improving binding, texture and water retention in meat, fish, dairy and plant-based products.
Oxidises glucose, producing hydrogen peroxide. Strengthens gluten in dough and is used in textile bleaching and oxygen scavenging.
An oxidase that acts on phenolic compounds. Used to stabilise juices and beer and to give denim a bleached look without harsh chemicals.
A proteolytic enzyme originally isolated from Serratia bacteria, used in pharmaceutical formulations for its anti-inflammatory action.
Pharmaceutical enzymes →A plant protease from papaya latex. Used in digestive formulations, meat tenderising and protein hydrolysis.
Papain →A protease from pineapple stem. Used in dietary supplements, meat tenderising and protein processing; activity is usually expressed in GDU.
Bromelain →The main protease of the stomach, active at low pH. Supplied to pharmacopoeia grades for digestive formulations.
A mixture of pancreatic enzymes — protease, amylase and lipase — used in enzyme-replacement and digestive formulations. Activity is specified per pharmacopoeia (IP, BP, USP, EP).
A starch-digesting enzyme preparation from Aspergillus, used in digestive syrups and tablets.
A milk-clotting enzyme preparation (chymosin and/or pepsin, or a microbial coagulant) that sets milk into curd in cheese making.
Key terms for specifying and formulating probiotic ingredients.
Live microorganisms which, when administered in adequate amounts, confer a health benefit on the host (FAO/WHO definition). Benefits are strain-specific.
Our probiotic strains →A genetically distinct sub-type within a species. Probiotic research and claims relate to specific strains, not just the genus or species name.
Bacillus species such as B. coagulans, B. subtilis and B. clausii form spores that tolerate heat, low moisture and stomach acid better than most lactic-acid bacteria — useful for baked goods, beverages and long shelf life.
A group including Lactobacillus (and related re-classified genera), Streptococcus thermophilus and Pediococcus. Used in fermentation and as probiotics.
Anaerobic gut bacteria (e.g. B. longum, B. infantis, B. animalis subsp. lactis) common in infant and adult probiotic formulations.
Saccharomyces boulardii and S. cerevisiae — yeasts used in human and animal products; unlike bacteria they are not affected by antibiotics.
A substrate selectively used by beneficial microorganisms, such as inulin, FOS or GOS. Often combined with probiotics.
A product that combines probiotics with a prebiotic or other substrate that supports them.
A preparation of inanimate microorganisms and/or their components that confers a health benefit (ISAPP definition). More stable than live cultures.
Extra viable count added at manufacture so the CFU on the label is still met at the end of shelf life, accounting for losses during processing and storage.
A measure of free water in a product. Low water activity is critical for the stability of dry probiotic and enzyme powders.
Words you will see on data sheets and in application notes.
The material an enzyme acts on — starch for amylase, protein for protease, lactose for lactase.
The pH at which an enzyme shows its highest activity. Acid, neutral and alkaline proteases, for example, are chosen to match the pH of the process.
The temperature of highest activity. Above it, activity falls as the enzyme begins to denature.
An enzyme’s ability to keep its activity at high temperature — important for feed pelleting, starch liquefaction and baking.
Irreversible loss of an enzyme’s shape and activity, caused by heat, extreme pH or chemicals. Often used deliberately to stop an enzymatic reaction.
How much enzyme is added, expressed as % of substrate, ppm, g per tonne or activity units per kg. The right dose depends on substrate, conditions and target effect, and is confirmed by trials.
Dosage calculator →The first step of starch processing: alpha-amylase thins gelatinised starch into soluble dextrins.
The second step: glucoamylase and other enzymes convert dextrins into fermentable sugars such as glucose and maltose.
Removal of starch size from woven fabric before dyeing, using amylase instead of harsh chemicals.
Textile enzymes →Enzymatic removal of pectin and waxes from cotton to improve absorbency — replacing hot caustic scouring.
Treating cotton with cellulase to remove protruding fibres and pills, giving a smoother, cleaner fabric surface.
A tannery step in which proteases clean the hide of residual proteins, making the grain smooth and the leather soft.
Leather enzymes →Slowing the firming of bread crumb over time, mainly with maltogenic amylase, to extend softness and shelf life.
Bakery enzymes →The inert material (e.g. maltodextrin, starch, salt) used to standardise an enzyme powder to its stated activity.
A product combining several enzymes — and sometimes probiotics — to act on different substrates at once, such as a multi-enzyme feed additive or digestive formulation.
Custom blends →Terms used in supplier qualification and regulatory files.
A document describing a product’s typical properties, activity, form, applications, storage and packaging. Every product page on this site has a TDS download.
Batch-specific test results confirming that a lot meets its specification — activity, microbiology, moisture and other parameters.
A document describing hazards, safe handling, storage and emergency measures. Enzyme powders can cause respiratory sensitisation, so dust control is important.
Official quality standards for medicines: Indian Pharmacopoeia, British Pharmacopoeia, United States Pharmacopeia and European Pharmacopoeia. A grade means the material meets that monograph.
Pharmaceutical enzymes →Suitable for use in food, meeting purity specifications such as those of the Food Chemicals Codex or JECFA and local food law (FSSAI in India).
Good Manufacturing Practice — the system of controls that ensures products are consistently made and tested to quality standards.
Our certifications →The international standard for quality-management systems, covering documented processes, traceability and continual improvement.
Food Safety and Standards Authority of India — the regulator that licenses food and food-ingredient businesses in India.
Religious dietary certifications confirming that ingredients and processes meet Islamic or Jewish dietary law — often required by food and supplement brands.
Registration of a facility with the US Food and Drug Administration, required for facilities that manufacture food or drug ingredients for the US market.
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Our application team can explain any specification, unit or test method — and share TDS and CoA documents for your qualification file.
