An Enzyme Often Used in Laundry — Amylase

A laundry enzyme: amylase (α-amylase)

1) What amylase does in the laundry

The core task of a laundry amylase is:to break down “starch-type stains”, cutting large starch molecules into smaller dextrins / oligosaccharides that dissolve more readily in water, so the stain is more easily carried away by the detergent.

In the enzyme classification, the amylases commonly used in laundry mostly belong to:

• EC 3.2.1.1 α-amylase

• The reaction:endo-hydrolysis of the (1→4)-α-D-glucosidic bonds in polysaccharides such as starch / glycogen, and the cutting is in a “random manner.”iubmb.qmul.ac.uk+1

In a single simplified sentence:Amylase = snipping the “starch gel stuck to the fibres” into soluble small fragments.iubmb.qmul.ac.uk+1

2) Why starch stains are especially hard to wash: they become a “sticky dirt gel”

Starch (especially gelatinised starch in cooked or processed food) readily swells in water and forms a viscous phase. Like a “glue,” it sticks other particulate soils in place, leading to:

• The stain itself being hard to rinse away

• A greater tendency, during the wash, forsoil redeposition / greying (dirt binding / redeposition)

Test and application data describe this clearly: if the starch is not broken down by amylase, it may spread through the wash and become a strong “dirt adhesive,” making wash performance worse.phadebas.com+1

3) Typical stains it is suited to: which situations “need amylase most”

Examples of “stubborn starch-type soils” commonly used in academic reviews and application literature include:

• **Rice, pasta, potatoes, corn, baby food, gravy / thickened sauces** and other “gelatinised starch stains”nopr.niscpr.res.in

• Also commonly listed:Sauces, chocolate, custard, ice creamand the like (mostly compound stains: starch + protein / fat / sugar).ScienceDirect+1

• Dried rice grains: This is a stain of extremely high physical hardness. Amylase can only work in a medium of “water.”

  SOP suggestion: For dried, hard rice-grain / dried-noodle stains,do not put them straight in the machine. You must soak them first for at least 20 minutes, so that water molecules first swell the starch structure, and only then can the enzyme get in and cut it.

• Suppliers’ public descriptions also point out that the starch in convenience foods (sauces, dressings, desserts and so on) is one reason stains are stubborn, and that a starch amylase can help.novonesis.com

4) The performance window a detergent-grade amylase needs (pH / temperature)

The laundry environment is mostly on the neutral-to-alkaline side, so detergent amylases are often designed to be “alkali-tolerant, temperature-tolerant, and able to work even in a short wash.”

Looking at products often used as examples of a detergent-type amylase in publicly available teaching materials (the Stainzyme / Termamyl type):

• They are active over a pH 7–11, 30–100 °Crange (the curve differs by product)NCBE Reading+1

• The maximum-activity point of one class of amylase can be at pH ≈ 9, and it is described as suitable forlow-temperature, short-cyclewashes.NCBE Reading

Amylase is usually a better match for a “neutral-to-alkaline wash”; and many laundry-grade products have already been adapted for low-temperature / short-cycle washes.NCBE Reading

5) Formula compatibility and stability: the points laundry operators most need to watch

Amylases of different origins / models differ greatly in how sensitive they are to the formula environment; but the following are common, practical points in suppliers’ materials:

1. Calcium-ion dependence and chelators

• Many amylases have a degree of Ca²⁺ dependence, and so may be unstable in the presence of a strong chelator. There are also engineered products labelled “more stable in the presence of a chelator, and with no need for extra calcium.”2.wlimg.com

1. Solubilising / stabilising systems

• Commercial descriptions note that certain polyols, non-ionic surfactants and the like have a positive effect on enzyme stability; at the same time they suggest avoiding particular hydrotropes (such as the sodium cumene sulfonate type) and antimicrobial systems that “can release formaldehyde.”2.wlimg.com

A practical suggestion:
Whether an amylase is “effective” depends not only on the wash but also on how well activity is maintained over the storage period. Release should be based on the supplier’s TDS / COA plus an accelerated stability test of the formula.2.wlimg.com

6) How to write the dosage in a way that is professional and can be put into practice

The more rigorous approach is:to decide it according to the enzyme’s activity units, the soil load, the wash conditions and the formula system; concentrations differ enormously by supplier, and a single fixed ratio should not be used.

If you need to give a “public example” in an article, you can quote a commonly suggested range from a supplier (the following are typical values in the description of a commercial detergent-grade amylase product, and are a product addition ratio, not pure enzyme protein):

• European formulas:0.1–0.3% w/w

• North America:0.2–0.4% w/w

• Asia-Pacific:0.05–0.2% w/w
  “The actual amount needs to be adjusted according to the wash, the formula, the dose and the target performance.”2.wlimg.com

7) Pairing with other enzymes / ingredients: amylase is usually the “second main force”

Most research and industry materials treat “protease” as the first main laundry enzyme, and amylase is often described as an important class second only to protease, because food stains often contain starch, and starch forms an adhesive matrix.ScienceDirect+1

Typical division of labour (you can put this in a diagram):

• Amylase: breaks down the starch gel (rice, noodles, thickened sauces, sauces)nopr.niscpr.res.in+1

• Protease: breaks down protein (gravy, milk, egg, sweat soils)

• Lipase: breaks down fats (cooking oil, sebum, greasy sauces)
  Once the starch has first been broken down, the effect of “sticking other soils in place” is often reduced, and overall stain removal is more stable.phadebas.com+1

8) Safety and occupational health: the key is “avoid inhaling dust / mist”

For occupational-exposure settings such as a laundry shop or factory, ACI and several associations pointed out in a 2024 risk guide for enzymes in professional cleaning:

• Enzymes as a whole have low toxicity and biodegrade quickly; the sustainability profile of a formula can also be improved by lowering the use temperature and substituting more irritating ingredients.American Cleaning Institute

• Butenzyme protein is a respiratory sensitiser. When the enzyme becomes dust or mist (aerosol / mist) in the air, inhaled exposure may lead to occupational allergy. The focus of risk management is thereforeto avoid generating inhalable particles(the form of the product, engineering controls, and operating rules).American Cleaning Institute

On the consumer side, AISE also cites research concluding that, in normal consumer-use situations, there isno evidence of a significant associationbetween enzyme-containing cleaning / detergent products and respiratory allergy.A.I.S.E.

9) A “key summary” you can paste straight onto a website

• Amylase (α-amylase) randomly cuts the starch’s α-1,4 glycosidic bonds, turning a starch stain into smaller, more soluble molecular fragments and improving washability.iubmb.qmul.ac.uk+1

• It is a particularly good match forrice, noodles, potatoes, thickened sauces, baby food and saucesand other “gelatinised starch stains,” and can also lower the risk of greying after the wash caused by starch acting as a sticky dirt gel.nopr.niscpr.res.in+1

• Laundry-grade products can often work in the pH 7–11range, and are also designed to be adapted for low-temperature / short-cycle washes.NCBE Reading+1

• On the professional side, you should particularly control for this:avoid inhaling dust / mist(management of respiratory sensitisation).American Cleaning Institute