Characterization of Boğazkere wines from different locations in Turkey relating aroma and sensory properties using chemometrics

Abstract

Boğazkere (BG) is one of the primary grape varieties that Turkey utilizes to produce premium red wine. Using chemometrics, this research was to investigate the aroma composition and sensory attributes of BG wines from various vintages and locations (Çermik/Diyarbakır, Güney/Denizli, and Pendore/Manisa). Using GC/MS/FID, GC-O, and Descriptive Analysis, aroma, aroma-active compounds, and sensory evaluations were identified and quantified, respectively. To determine the relationship between chemical result and sensory perception, PLS Regression (PLSR) was used. Principal component analysis (PCA) was used to evaluate the sensory results. There have been identified 93 aroma compounds, 29 of which are aroma-active compounds for which modified frequency (MF%) values have been determined. Compounds with high MF% values in BG wines include ethyl-3-methyl-butanoate/ethyl-2-methyl-butanoate (86), ethyl-2-methyl-propanoate (83), isoamylalcohol (82), ethylhexanoate (80), diethylsuccinate (77), and 2-phenylethylalcohol (75). The most prominent attributes associated to these compounds are those of black-fruit, red-fruit, strawberry, raspberry, banana, dry-fruit, cheery and spicy. PCA indicated that the most prevalent aroma descriptors for BG wines are black fruit, dried fruit, red fruit, confectionery, and spicy. Although dry-fruit, black-fruit, and spicy notes are more prevalent in wines from Diyarbakır, red-fruit and confectionary odours are more prevalent in wines from Denizli and Manisa. Red-fruit attributes in wines were positively correlated with diethyl-dl-malate, ethyl-butanoate, ethyl-hexanoate, ethyl-octanoate, ethyl-decanoate, ethyl-3-methylbutanoate, and ethyl-2-methylbutanoate, depending on PLSR. Ethyl-2-hydroxy-methylpentanoate, 4-ethoxycarbonyl-gamma-butyrolactone, gamma-nonalactone, pantolactone, and ethyl-2-methyl-propanoate were positively correlated with the dark fruit attribute of wines. Ethyl-2-hydroxy-4-methyl-pentanoate and gamma-nonalactone compound, which gives the odours of black fruit (blackberry), is particularly noticeable in Diyarbakır wines.