Aroma studies of fruits and wine in Israel

Bound and free aroma compounds analysis in must and wines produced in Israel showed ratios of bound to free varying between 1 to 4. In order to utilize this aroma potential efforts were made to find enzymes capable of hydrolyzing the glycosidic bonds. Selection of microorganisms grown on medium consisting of monoterpene glycosides as a sole carbon source and adjusted to a pH of 3.4 resulted in a specific Aspergillus Niger which produces a unique P-glucosidase capable of efficiently hydrolyzing glycosides in wine and must. Sensory evaluation tests well coincided with GC-MS analyses, indicating an efficient enhancement in wine quality. The recent introduction of SPME extraction device during the last decade, has greatly improved our capabilities to extend our studies on the effect of cultural practices on aroma components. In field studies we have found that Phosphorous fertilization had positively affected leaf P content and bound aroma compounds as well as wine score by sensory evaluation in cv Cabernet sauvignon. Irrigation with saline water has significantly affected 16 various volatiles of Cabernet sauvignon in the southern arid zone of Israel-the Ramat Negev region. Moderate salinity of 2.7 d S/m in the irrigation water was found to enhance wine quality as determined by sensory evaluation. Cabernet sauvignon on Ruggeri rootstock was found to enhance the aroma and the wine quality in comparison to similar vines on Salt creek rootstocks.