Optimization of Two‐Step Cotton Scouring with β‐Cyclodextrin and Alkaline Pectinase

Abstract The hydrophobic cuticle of cotton fibers has formed a natural barrier for individual pectinases to catalyze its substrates (pectins beneath the cuticle), thus resulting in an insufficient bio‐scouring. β‐Cyclodextrin with a special non‐polar cavity is accommodating some organic compounds (dyestuffs, functional finishes, etc.) to form stable inclusion complexes. It has been demonstrated that β‐cyclodextrin can be used as a scouring agent of cotton fabric because this special inclusion helps to remove hydrophobic waxes in the cuticle of cotton. Considering possible synergetic effects between pectinase and β‐cyclodextrin which might lead to better cotton scouring effects, two reverse cases of scouring processing, β‐CD treatment followed by pectinase treatment and pectinase treatment followed by β‐cyclodextrin treatment, were put forward. For each scouring processing, optimal scouring parameter dosages of pectinase and β‐cyclodextrin as well as incubation time were determined by means of wettability. β‐CD treatment followed by pectinase treatment produced a better scouring effect than β‐CD treatment following pectinase treatment because the partially elimination of hydrophobic waxes and fats in the cotton cuticle could increase the accessibility of the subsequent pectinase to the substrates. Finally, the whiteness and strength of the bleached cotton fabrics and the K/S values (color depth) of the dyed cotton fabrics were measured and compared with those of conventionally alkali‐treated ones.