Study on Fungal Exopolygalacturonase Precipitation with Organic Solvents

Pectinases constitute a group of enzymes that act on pectic substances, acid polysaccharides present in the primary wall of plants. Pectinases are used in the food industry, in the processing of fruits, in pulp maceration, in the extraction and clarification of juices and in the wine industry. The juice extraction is carried out, generally, by the pressing and partial destruction of the pectin through the enzymatic treatment of the pulp. The application of pectinases in the extraction, purification and clarification of citric fruit juices, as agents facilitating the extraction operation, allowes an increase in the quantity of juice extracted and improves the fruit pigment extraction. An increase in the efficiency of essential oils extraction from citric fruits is also indicated as an advantage of the use of pectinases. The concentration processes of these enzymes obtained through fermentation by the solvent precipitation method with organic solvents, such as: ethanol, acetone, propanol and isopropanol, at temperatures of 0oC, 4oC, 10oC and 20oC and concentrations of 10%, 20%, 30%, 40% and 50% (v/v/), were studied and the best results were obtained with ethanol as the precipitation agent, mainly at temperatures of the 0oC and 10oC. The results obtained for the precipitation at 0°C, at an ethanol concentration of 20%, indicated an approximately 100% recovery of enzymatic activity which demonstrates the success of the method applied.