Detergents are synonymous with any chemical that cleans or get rid of stains. They have been used to remove stains since centuries ago, particularly when the most fundamental form of a detergent or surface active agents (surfactants)—soaps, were created out of ashes and fat (Levey, M. (1958) Gypsum, salt and soda in ancient Mesopotamian chemical technology. Isis. 49(3): p. 336-342.). Soaps, however, do not work in water with high level of metal ions or ‘hard water’ because soaps are ionic, and these imminent ionic interactions between soaps and metal ions would just deactivate soaps, and emulsification would be impossible. Considering that water quality in general is unpredictable, detergent formulations must be considered to work in most conditions.
Fortunately, modem detergents nowadays consist of complex chemicals, such as highly developed surfactants and water softeners. These surfactants are better than normal soap because they can perform better in water that is high in metal ions, especially calcium, magnesium, and iron. Many of the ingredients of modern detergents are also made from renewable raw materials, such as sugar alcohols and biodegradable polymers. The trend of shifting from petrochemical-based to oleochemical-based surfactants can be seen as the awareness on the environment and petroleum depletion rises.
In recent years there has been an ever increasing trend towards safer and environmentally friendly detergent compositions. This trend imposes additional constrains onto the dishwashing formulator. In terms of energy efficiency and raw material savings, it is desirable to design products which provide good performance even at low temperatures and with a reduction on the amount of chemicals, in particular non-readily biodegradable chemicals.
The use of enzymes in detergent formulations is becoming popular due to the concerns on the environment. It has been found to be very useful to have enzymes in dishwashing detergent compositions because enzymes are very effective in removing food soils from the surface of glasses, dishes, pots, pans and eating utensils. Björkling, F., Godtfredsen, S. E., and Kirk, O. (1991).
The future impact of industrial lipases. Trends Biotechnol. 9(1): p. 360-363 reports rapid gaining interest in enzyme use in a detergent formulation due to its biodegradability and ability to function at lower temperature. Unlike conventional detergents that get rid of stains and enter waterways, the use of enzymes could help alleviate water pollution in which the enzymes can degrade the stains and be degraded before they enter waterways. In addition, some enzymes can perform specific functions better than conventional methods involving chemicals. For example is cellulase, which can enhance fabric appearance and structure by modifying the cellulose fibers [Kuhad, R. C., Gupta, R., and Singh, A. (2011) Microbial cellulases and their industrial applications. Enzyme Res. 2011: p. 280696]. Like other detergent components, detergent enzymes are also constantly being improved; for example, a better protease [Souter, P. F. U. (2011) Automatic Dishwashing Detergent Composition. U.S. Pat. No. 8,008,241 B2] with better functionality and a better amylase [Aehle, W. and Amin, N. S. (2011) Variants of An Alpha-Amylase with Improved Production Levels in Fermentation Processes. U.S. Patent 2011/0027252 A1] with better stability. Unlike proteases and amylases, lipases have not Been extensively used in automatic dishwashing detergents but are becoming more popular, especially in reducing the amount of surfactant use.
Thus in view of the state of art cited above it is a major interest of the present invention to provide a novel detergent formulation for an automatic dishwashing machine, wherein the formulation comprising an improved enzymatic system comprising an improved lipase [preferably a thermostable lipase (T1 lipase)]. T1 lipase (E.C. 3.1.1.3) was evaluated for its stability and performance in dishwashing along with other common components of an automatic dishwashing detergent. The formulation of the invention provides cleaning and finishing benefits across a wide range of temperatures, including high temperatures, improving the energy profile of the dishwashing process. Surprisingly, the formulation of the invention allows for a more energy efficient dishwashing processes without compromising in cleaning and finishing. This invention is a new approach to simplify conventional methods in the development of a detergent formulation for an automatic dishwasher.
The T1 lipase was tested in hard water with fairly low builders, whereas other known Formulations mostly focused on high amount of builders or builders that are efficient, such as phosphates, in order to make the surfactants work. In addition, the formulation developed in the present invention is stable at high temperature, so it is suitable for automatic dishwasher, which are normally intended for high temperature washings.
The functionally of the enzyme is said to remove food soils from the surface of glasses, dishes, pots, pans and eating utensils. However, in order for the enzyme to be highly effective, the formulation must be chemically stable, and it must maintain an effective activity at the operating temperature of the automatic dishwasher.
In view of the above discussion, an objective of the present invention is to provide an eco-friendly product that at the same time provides excellent cleaning and finishing benefits.