Many detergent brands are based on a blend of two or more enzymes - sometimes as much as eight different enzymes. One of the driving forces behind the development of new enzymes and the modification of existing ones for detergents is to make enzymes more tolerant of other ingredients, such as builders, surfactants, and bleaching chemicals, as well as of alkaline. The trend toward lower wash temperatures, in particular in Europe, has also increased the need for additional and more efficient enzymes. Starch and fat stains are relatively easy to remove in hot water, but the additional cleaning power provided by enzymes is required in cooler water.
Most widely used enzymes
The most widely used detergent enzymes are hydrolases, which remove protein, lipid, and polysaccharide soils. Research is currently being carried out with a view to extending the types of enzymes used in detergents. Many complex, stubborn stains come from a range of modern food products such as chocolate ice cream, baby food, desserts, dressings, and sauces. To help remove these stains as well as classic stains such as blood, grass, egg, and animal and vegetable fat, a number of different hydrolases are added to detergents.
The major classes are proteases, lipases, amylases, mannanases, cellulases, and pectinases. Historically, proteases were the first of these to be used extensively to increase the effectiveness of laundry detergents. Cellulases contribute to cleaning and overall fabric care by maintaining, or even rejuvenating, the appearance of washed cotton-based garments through selective reactions not previously available when washing clothes with surfactants unamended with enzymes.
Some lipases can act as alternatives to current surfactant technology by targeting greasy lipid-based stains.
Recent investigations show that multi-enzyme systems may replace up to 25% of a laundry detergent’s surfactant system without compromising the cleaning effect. This leads to a more sustainable detergent that allows cleaning at a low wash temperature.
Mannanases and pectinases are used for hard-to-remove stains of salad dressing, ketchup, mayonnaise, ice cream, frozen desserts, milkshakes, body lotions, and toothpaste as well as banana, tangerines, tomatoes, and fruit-containing products such as marmalades, juices, drinkable yoghurts, and low-fat dairy products.
The obvious advantages of enzymes make them acceptable for meeting consumer demands. Due to their catalytic nature, they are ingredients requiring only a small space in the formulation of the overall product. This is of particular value at a time where detergent manufacturers are trying to make their products more compact.
Washing with laundry bars.
In many parts of the world, strongly colored and stubborn stains from blood, sebum, food soils, cocoa, and grass are removed with the help of laundry detergent bars.
Such stain removal and washing by hand are one of the more time-consuming and physically demanding domestic tasks which can be made easier with the use of enzymes. After decades of very little performance enhancement for laundry bars, a specially formulated protease that empowers the producer to create products that stand out from non-enzymatic laundry detergent bars is now available, offering effective and effortless washing.
With the protease product Easyzyme® in laundry bars, washing is shortened by at least one rinse and requires much less scrubbing. In addition to obtaining a superior result, laundry bars containing the enzyme may be formulated to be milder to the hands than old-type bars without enzymes.
Most of the energy spent during a household machine wash is used to heat the water. Thus, the most efficient way to save energy and thereby reduce carbon dioxide emissions is to lower washing temperatures.
The wide spectrum of enzymes that are available today, combined with a choice of appropriate other ingredients such as surfactants and bleaching systems specifically selected to work at low temperatures, has enabled manufacturers to produce cold water detergents.
Enzymes in dishwashing
Modern dishwashing detergents face increasing consumer demands for efficient cleaning of tableware. Enzymes are key ingredients for effectively removing difficult and dried-on soils from dishes and leaving glassware shiny. Enzymes clean well under mild conditions and thereby assist to reduce clouding of glassware.
In addition, enzymes also enable environmentally friendly detergents. Phosphates have been used in the past in dishwashing detergents to get dishes clean, but they harm the aquatic environment and are increasingly being banned in detergents around the world. The combination of modifying detergent compositions and using multi-enzyme solutions enables detergent manufacturers to replace phosphates without compromising the cleaning performance. For removal of protein soils, proteases are used; and amylases are used to remove starch soils.
Proteases for cleaning dishes and cutlery.
Some of the more difficult soils on dishes and cutlery are blends of egg yolk/milk, egg yolk, whole egg, and egg white as well as minced meat and oatmeal. The reason for this is the content of protease inhibitors in these foods. The protease Blaze Evity® by Novozymes has been specifically engineered to overcome high levels of protease inhibitors from eggs. These inhibitors effectively inactivate detergent proteases, resulting in reduced cleaning performance not just on the egg stain itself, but on all protein-containing soils in the same dishwasher load.
Amylases for cleaning starch-containing soils from dishes.
In automatic dishwashing, most of the soil is physically washed off by the water jets. However, foods usually leave behind thin films of starch-/protein-containing soils. If they are not removed, these films will build up over time. Larger lumps of burnt-on and caked-on soils may also remain. These soils are the main target for enzymes.