Production of a alfa-L-rhamnosidase from Aspergillus terreus using citrus solid waste as inducer for application in juice industry

Naringinase is an enzyme complex consisting of a α-L- rhamnopyranosidase (Rha, EC. 3.2.1.40) and β-D-glucopyranosidase (βG, EC. 3.2.1.21). α-L-rhamnopyranosidase is an enzyme of considerable importance in food technology for increasing the aroma of fruit juices and alcoholic beverages. It is particularly used for debittering of citrus-juice by the hydrolysis of naringin and hesperidin, however this activity is low in commercial enzyme preparations. The aim of this work is the production of Rha from Aspergillus terreus fermentation using citrus solid waste (CSW), called "pastazzo", as specific inducer. CSW is rich in fermentable materials such as sugars, in particular rhamnose, in pectins, and in flavanone glycoside as hesperidin and naringin. Rha and βG have been characterized from a culture of A. terreus.