Abstract
The removal of unitary and the mixed oily soils of triolein and its hydrolysates such as diolein, monoolein and oleic acid from cotton fabric were examined by changing the surfactant and pH of the washing solution. Using various lipases having different positional specificities of hydrolysis, triolein soiled fabrics were washed by a surfactant solution containing lipase.
By a nonionic surfactant, monoalkyl deca (oxyethylene) ether (APE), unitary and the mixed soils of triolein and its hydrolysates could all be removed to nearly the same extent regardless of the kind of glyceride. By an anionic surfactant, sodium lauryl sulfate (SDS), diolein and monoolein were removed in preference to triolein. In alkaline solution, oleic acid could be removed most easily by formation of oleic acid soap, which promoted the removal of other glycerides present.
In the removal of triolein by SDS containing lipase at pH 7.0, lipases with positional specificity and which accumulated di- and monoglycerides in the reaction mixture were more effective than those without positional specificity producing considerable amounts of free fatty acid. In the removal of triolein by APE containing lipase, no significant difference in the extent of removal depending on the particular kind of lipase could be observed. These results agree well with those for the removal of triolein and its hydrolysates by a surfactant solution.
