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The aim of the present study was to reinforce starch-based films with psyllium mucilage in order to obtain natural, edible, and biodegradable films with improved mechanical and functional properties. The rheological properties of film-forming solutions can be controlled by the concentration levels of added mucilage. The addition of mucilage reduced the decomposition of the system, which made these films more thermally stable. Those starch-mucilage films were sufficiently transparent and exhibited a low aqueous solubility and as shown in SEM images of such films spherical particles appeared in the structure, probably microcapsules. The addition of mucilage did see an improvement in the mechanical properties of those films, especially at a higher concentration of starch (4% rather than 3%). [ABSTRACT FROM AUTHOR]

After illumination with white, linearly polarized light (WLPL), cyclodextrin glycosyltransferase produced mixture of α-, β-, and γ-cyclodextrins (CD) with higher overall yield than did that enzyme when nonilluminated. The illumination also influenced the ratio of those CD and that effect depended on concentration of enzyme and illumination time. At a high enzyme concentration (0.64 U/cm3), regardless the illumination time, formation of β-CD predominated. The highest yield of β-CD was afforded after 1 h illumination and 2 h illumination led to a significant increase in the yield of γ-CD. Three-month storage of enzyme illuminated with WLPL did not reduce its enhanced activity. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [ABSTRACT FROM AUTHOR]

The 1- to 2-h illumination of xylanase with visible polarized light (PL) prior to the action of that enzyme upon beechwood xylan significantly increased its activity. The activity only negligibly decreased on 3 months storage. The hydrolysis of xylan proceeded in three well-distinguished stages. In the first and fastest stage the effect of illumination was only slightly positive. The effect of the stimulation was noted in the second, slower stage. Enzyme stimulated with PL, preferably by means of the 2-h illumination, performed better than enzyme stimulated with nonpolarized light and non-stimulated enzyme. In the last, the slowest stage, the rates of the reaction were nearly the same using either stimulated or non-stimulated enzyme.