Filing Date: 2005-12-15.-- Priority Data: ES P 200402994 (2004-12-16).The invention relates to a method of producing industrially-viable prebiotic oligosaccharides using a novel enzyme of Xanthophyllomyces dendrorhous, which is characterised by having α-glucosidase activity. The invention also relates to a method of obtaining an enzymatic product with α-glucosidase activity and the substantially-pure enzyme with α-glucosidase activity. The enzymatic product and the enzyme offer the advantage of having a high performance spectrum and a high specific activity. Said prebiotic oligosaccharaides are used in food.