Enzyme Scouring Of Cotton Fabric

Enzymatic activity is an important parameter in its applications. Generally, assay for pectinase activity used pectin from fruit as its substrate, but its activity determinated can't reflect its role in the textile scouring accurately; therefore, finding a substrate that can reflect its bioscouring effect is significant.In this paper, ammonium oxalate was used to extract pectin from ramie(fiber pectin) and the conditions for extraction were optimized. The structure and properties of fiber pectin such as appearance, solubility, ashes, pH, methoxy content and content of galacturonic acid was studied.The optimal conditions for fiber pectin's extractions are summarized as follows:the extracting temperature was 90℃, the extracting time was 90min, and the concentration of ammonium oxalate was 5g/L.Some pectinases activities were determinated by DNS method and ultraviolet spectrophotometric method using different pectins as substrate, the experimental results showed that pectinase activities determinated by DNS method and ultraviolet spectrophotometric method coincide well with each other, which means that both methods are effective method for assay of pectinase activity. The acidic pectinase A activity using apple pectin as substrate was 15594.2U/mL, close to the activity(16000U/mL) supplied by the company, but it owned poor activiy(417.3 U/mL) using fiber pectin as substrate. The results indicated that acid pectinase A owned strong hydrolyze effect on apple pectin and poor hydrolyze effect on fiber pectin.The activity of alkaline pectinase using fiber pectin as substrate was 151.6U/mL, drawing near to the activity (150 U/mL) given by the company, but the activiy using apple pectin as substrate was only 5.3U/mL, which indicated that alkaline pectinase owned strong hydrolyze effect on fiber pectin and poor hydrolyze effect on apple pectin. The ratio of pectinase activity was using fiber pectin as substrate to apple pectin as substrate, which was defined as "the ratio of enzyme activity ". The ratio of alkaline pectinase> 1 indicted that Alkaline pectinase owned strong hydrolyze effect on fiber pectin, the ratio of acidic pectinase<1 indicted that acidic pectinase owned strong hydrolyze effect on apple pectin.On the basis of single factor experiment, the conditions for determination of pectinase activity and pectinase souring were optimized. The results showed that the optimum conditions of alkaline pectinase souring were summarized as follows:the concentration of alkaline pectinase was 2.0g/L, the PH value was in the range of 7-9, the temperature was at 55-65℃, the treatment time was 60 min, the bath ratio was 30:1. The optimum souring conditions of acidic pectinase A was summarized as follows:the concentration of acidic pectinase A 0.5g/L, the pH value was in the range of 4-5, the temperature was at 45-55℃, the treatment time was 60 min, the bath ratio was 30:1.Alkaline pectinase owned better souring effect than in the same activity acidic pectinase A, alkaline pectinase scouring was superior to acidic pectinase A souring. These results validated that alkaline pectinase owned strong hydrolyze effect on fiber pectin and acidic pectinase A owned poor hydrolyze effect on fiber pectin.