EFFECTS OF KAOLIN AND DICARBOXYLIC ACID BASED STRESS INHIBITORS ON AROMA COMPOSITION OF TWO TABLE GRAPE CULTIVARS (V. vinifera L.)

In this study, effects of two stress inhibitors (particle film - PF and dicarboxylic acid - DA) on aroma composition of Beauty Seedless and Tekirdag Seedless grape cultivars were investigated. Analysis of the aroma components was carried out using solid-phase microextraction technique with gas chromatography (GC) and mass spectrometry (MS). A total of 36 and 24 aroma compounds were identified in Beauty Seedless and Tekirdag Seedless, respectively. The C-6-compounds (hexanal and 2-hexenal) were determined as the most abundant compounds in both grape cultivars and they accounted for 40.1% and 72.3% of total aroma composition in Beauty Seedless and Tekirdag Seedless, respectively. Monoterpenes (geraniol, nerol and neric acid) and sesquiterpenes (alpha-ylangene and germacrene) had a significant contribution of 35% to the total flavor of Beauty Seedless. Benzophenone, maltol, 6-methyl-5-hepten-2-one, 2-ethyl hexanol, 2-pentyl furan, acetic acid, hexanoic acid were other compounds detected at the highest amount. In Tekirdag Seedless, benzene acetaldehyde, 2-ethyl hexanol, maltol, 4-hexen-1-ol, acetic acid and hexanoic acid were determined as proportionally important compounds. When taken into consideration the use of stress inhibitors becoming an interesting area in viticulture, the effects of treatments in the aromatic composition is limited. In the presented study, proportional levels of any aroma compounds could not be attributed to influence of the stress inhibitors. However, findings presented useful contribution for future studies. On the other hand, this study is the first report on aroma composition of Beauty Seedless and Tekirdag Seedless grape cultivars.