Polyols’ effect on thermal stability of lipase and its application in cotton fabrics’ enzymatic treatment

In this paper, the effect of polyols on thermal stability of lipase was investigated. Lipase, with or without polyols was heated at 75°C for different periods of time. Half-life (t1/2, min) of lipase at 75°C was prolonged from 8.74 to 12.62, 11.66, 9.45, and 8.95 with the addition of d-sorbierite, d-fructose, mannite, and maltose, respectively. Conformational changes of lipase after the heat treatment were studied by both Fluorescence spectra test and UV spectra test. The UV values (as the unfolding ratios of lipase) calculated from UV spectra were related to the proportion of inactivated lipase. Residual activityUV (originated from UV values) reflected residual lipase activity from the experimental data accurately. Compared with cotton fabrics treated by the crude lipase at 75°C, the appearance of polyols enhanced the capillary effect and weight loss of cotton fabrics to some extent.