CHARACTERIZATION OF PINEAPPLE LEAF FIBER FOLLOWING ENZYMATIC DEGUMMING

Abstract

Pineapple leaves are a rich resource of fiber with excellent properties. To overcome the processing bottleneck, the enzymatic degumming conditions with compound enzymes, comprising laccase and xylanase, on low-concentration alkaline-pretreated pineapple leaf fiber (PALF), were investigated. The cellulose content and fiber splitting degree were used as optimization indicators. Treated PALF characteristics were determined using microscopic morphology, XRD, and FTIR analysis techniques. The optimal conditions were found as: 0.5% laccase, 0.3% xylanase, bath ratio of 1:50, pH 4.6–5.0, and incubation at 50–55 °C for 4 h. Following enzymatic degumming, the cellulose content increased from 57.22 to 74.46%, the lignin and hemicelluloses contents decreased, a large number of colloidal impurities were hydrolyzed, and free fibers with smooth surfaces were released. The crystalline cellulose remained type I, and crystallinity increased from 36.46 to 46.73%. Low-concentration alkaline solutions, combined with compound enzymes that effectively hydrolyze colloids, resulted in mild enzymatic degumming that caused less damage to cellulose.