Highly active xylanase used in juice clarification

Abstract

Xylan makes a significant part of cereals and fruits, which are used in the food industry. Therefore, enzymes that hydrolyze xylan (xylanases) have found application in the modification of cereal-based food, improving the digestibility of animal feed, and improving the texture of bakery products. In the juice industry, the main problems are turbidity, viscosity, and sedimentation during standing, which are caused by polysaccharides present in fruit (pectins, cellulose, and hemicellulose (xylan)). Pineapple, apple, orange, and tomato have a high content of hemicellulose, so xylanases are suitable for improving the properties of these juices. The Aspergillus tubingensis FAT 35 strain (considered safe for use in the food industry) growing on SSF medium composed of corn cob produced a high level of xylanase enzyme (4.03 U∕mL) and not that high pectinase (1.02 U∕mL) and cellulase (1.43 U∕mL) activities at pH 3 which is pH of freshly prepared apple, pineapple and organge juice.. The fermentation extract was used for clarification of pineapple, apple, and orange juice and for increasing the filtration rate and yield of these juices. Results indicate that A. tubigensis xylanase could be used for clarification and improvement of properties of juices of fruits that contain hemicellulose in high proportion.