Characterization of β-glucosidases from Hanseniaspora sp and Pichia anomala with potentially aroma-enhancing capabilities in juice and wine

The properties of intracellular beta-glucosidases produced from two yeast isolates identified as Hanseniaspora sp. BC9 and Pichia anomala MDD24 were characterized. beta-Glucosidase from Hanseniaspora sp. BC9 was not inhibited by both 20% w/v fructose and 20% w/v sucrose and was slightly inhibited by glucose (> 40% relative beta-glucosidase activity with 10% w/v glucose). beta-Glucosidase from P. anomala MDD24 was inhibited by glucose, fructose and sucrose. In the presence of 4-12% v/v ethanol, beta-glucosidase from P. anomala MDD24 was stimulated in range 110-130% relative activity whereas beta-glucosidase from Hanseniaspora sp. BC9 was substantially inhibited in the presence of ethanol. Finally, juice and wine of the Muscat-type grape variety, Traminette, were selected to determine sugar-bound volatile aroma release, particularly terpenes, by the activity of those beta-glucosidases. The results showed that high concentration of free aroma compounds were detected from Traminette juice treated with beta-glucosidase from Hanseniaspora sp. BC9 and Traminette wine treated with beta-glucosidase from P. anomala MDD24. The preliminary results with proposed an application of these enzymes in commercial wine production lead to more efficient of beta-glucosidase from Hanseniaspora sp. BC9 in releasing desirable aromas during an early stage of alcoholic fermentation while beta-glucosidase from P. anomala MDD24 is suitable at the final stage of alcoholic fermentation.