HYDROPHOBIC REGIONS OF HEMICELLULOSES ESTIMATED BY FLUORESCENT-PROBE METHOD

The hydrophobicities of some hemicelluloses were estimated by a flourescent probe method. The maximum wave lengths in emissions (lambda(max)) of 8-anilino-1-naphthalenesulfonic acid (ANS) in hemicellulose solutions were measured, and the blue shift of lambda(max) was observed as a function of the hemicellulose concentration. The hydrophobic intensity of hemicellulose was estimated by the value of lambda(max). From the results, softwood hemicellulose was more hydrophobic than hardwood hemicellulose and citrus pectin. Especially, the hydrophobic region in softwood hemicellulose is more hydrophobic than 1,4-dioxane. Furthermore, the hydrophobic capacity was estimated by the requisite amount of hemicellulose capturing the unit amount of ANS. From the results, it was found that softwood hemicellulose has a slightly larger hydrophobic capacity compared with hardwood hemicellulose. However, the hydrophobic capacities of woody hemicelluloses were 2/3-3/4 compared with that of pectin.