Bleaching commercial applications

Titanium Trichloride Hexahydrate. Titanium trichloride hexahydrate [19114-57-9] can be prepared by dissolving anhydrous titanium trichloride in water or by reducing a solution of titanium tetrachloride. Evaporation and crystallization of the solution yield violet crystals of the hexahydrate. The hydrated salt has had some commercial application as a stripping or bleaching agent in the dyeing industry, particularly where chlorine must be avoided. 

Lipoxygenases will also catalyse co-oxidation reactions. This is used both in assay methods for the enzyme and in commercial applications. An example of the latter is the addition of soybean or broad bean flours (both rich in lipoxygenase activity) to wheat flour in order to bleach pigments for white bread production. Enzymes from different sources differ in their co-oxidation ability, e.g. soybean type-I enzyme has poor activity in this regard while soybean type-II enzyme has high co-oxidation activity. The reaction probably proceeds by a free-radical process (Veldink et al., 1977) and requires the presence of a substrate (e.g. linoleic acid) as well as the co-substrate. The extent of the cooxidation may depend on the lifetime of the radical intermediates and the relative efficiency of the lipoxygenase-mediated radical reduction (Weber and Grosch, 1976). 

The ability of LOX to catalyze cooxidation reactions has long been recognized (e.g., its carotene oxidase activity see Section I) and has been used as the basis for some LOX assays (see Section IV) and in commercial applications e.g., soybean or Vida faba flours (both rich in LOX activity) are added to bleach wheat flour pigments in white bread production. Cooxidation is clearly manifested in the bleaching of pigments (chlorophyll, carotenoids, etc.) but also results in the oxidation of protein-SH groups and of unsaturated fatty acids, including substrates for LOX. 

Sodium hypochlorite [II, 21.2.2d. Sodium hypochlorite is a clear, slightly yellow liquid aqueous. Household bleach has active concentrations between 5.25 and 6.00% whereas concentrations of 5 to 15% are used in the industry. Most commercial applications use the more concentrated solutions. One gallon of sodium hypochlorite yields approximately the same quantity of active chlorine as one pound of chlorine gas. 

Increasing demands on the performance of detergents have led to the use of enzymes in detergent formulations destined for both domestic and commercial applications. To a degree, enzymes can take the place of chlorine bleach and phosphates, both of which can have detrimental environmental consequences. Lipases and ceUulases are the most useful enzymes for detergent applications. 

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