Experimental Methods
Enzyme Treatments
Laboratory Scale Hanks of yam sample B were seoured for 30 min at 60°C in a Horsfall hank-sample-dyeing machine at a liquor-to-fibre ratio of 250 mL/g in an aqueous
solution containing 1.2 mL/L of non-ionic surfactant Sandozin NIN cone, and 1.6 g/L of sodium carbonate.
Yam samples were rinsed with water and immediately treated with a range of concentrations of Novozym 655L (from 0.09 to 0.45 mL enzyme product per g of fibre) in ammonium sulphate buffer with its pH adjusted to 8.0.
The treatment temperature was first set at 40°C for 20 min and then raised to 57 ^ (at a rate of l°C/min) and maintained for 60 min.
Treated samples were washed at 30°C with 0.25 niL/L Sandozin NIN cone, at pH 5 and then in hot water at 80°C for 10 min to inactivate residual enzyme.
Finally,yams were rinsed with cold distilled water, spun dry, and conditioned at 20 ± °C and 65 ± 2% r.h. The progress of enzymatic treatments was monitored via weight loss, changes in yam tensile properties, and changes in the compression behaviour of bundles of free
fibre ends .