Influence of Pectinase Adsorption on Scouring Efficiency of Mercerized Cotton Yarns

The low scouring efficiency of mercerized cotton yarns scoured with alkaline and acid pectinases, reported in previously published articles, raised the hypothesis of the lack of pectinase adsorption onto mercerized cotton. In an attempt to identify whether low pectinase adsorption occurs, the adsorption of alkaline and acid pectinases on raw and mercerized cotton yarns is measured using the Lowry protein assay, while laser-scanning confocal fluorescence microscopy is used to visually show the presence/absence of the enzymes on the surface of the cotton yarns. In addition, the surface zeta potential of the raw and mercerized cotton yarns is measured to identify the influence of the surface charge on the adsorption ability of the used enzymes. Data suggest that although used substrates have adsorbed more alkaline than acid pectinase, the adsorption of both enzymes is more intensive onto the mercerized cotton relative to raw cotton. The similar surface zeta potential of the raw and mercerized yarns indicates that higher enzyme adsorption on mercerized cotton is not influenced by the surface charge. Laser-scanning confocal fluorescence microscopy micrographs depict an evident increase of fluorescing signal with scouring time to raw and mercerized cotton yarn. The more intensive signals after 60 min of enzymatic scouring with both enzymes suggest enzyme presence on the yarn surface after a long treatment time. The obtained results confirm the enzyme retention on the yarn surface, thus excluding the hypothesis that the absence of enzyme adsorption is a factor for the low scouring efficiency of mercerized cotton yarns.