Fractionation of glycoside aroma precursors in neutral grapes. Hydrolysis and conversion by Saccharomyces cerevisiae

Glycoconjugated aroma precursors from neutral grape varieties were fractionated on 5g C18 RP cartridge. Each of the seven fractions collected was divided in three parts: first part was hydrolysed with Pectinol in order to determine total aromatic heterosides, while the second part was treated with an active strain of the yeast Saccharomyces cerevisiae UCLM 325 and the third part with acetonic powder of the same yeast strain. The studied strain proved effective in the hydrolysis of the heterosides of nerol and geraniol, cis-8-hydroxy-Iinalool, 8-hydroxy-dihydro-linalool, some berizenoids and some norisoprenoids derivatives Such as vomifoliol and 3-oxo-alpha-ionol. Only whole cells are able to convert geraniol to citronellol. (C) 2003 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.