Sensory analysis and headspace / gas chromatography of italian hazelnut varieties.

This study presents preliminary comparative results of volatile components and sensory responses of ‘Tonda Gentile Romana’, ‘Tonda di Giffoni’ and ‘Mortarella’ cultivars. The sun-dried, natural hazelnut samples were roasted at 120°C for 20 min, using a hazelnut roaster (Brovid R1/900-OB-V). The characteristics of the roasted hazelnuts were described and evaluated by a panel made up of 8 tasters. Each taster tasted 3-5 hazelnuts at a time and the panel test was done 3 times per each cultivar. Descriptive sensory analysis showed that ‘Tonda Gentile Romana’ was mainly characterized by almond-like flavour, ‘Mortarella’ hazelnut by oily taste and ‘Tonda di Giffoni’ hazelnut by caramel-like flavour. The most important flavour attributes were nutty, caramel-like and cooked-bread-like. The taste and aftertaste attributes detected are sweet, salty, bitter, almond-like, nutty, burnt, and oily. The bitter taste attribute was not detected in ‘Tonda di Giffoni’. ‘Tonda di Giffoni’ showed the highest intensity of nutty aroma and of sweetness. All of the hazelnut varieties were characterized for their chemical composition of volatile components. Compounds including ketones, aldehydes, terpenes and cyanide derivatives were detected and identified by SPME-GCMS analyses. Among these classes of compounds, qualitative and quantitative differences were found in the different cultivars. Specific compounds such as filbertone, linalool and 1,4 cineole showed significant variations between the three different cultivars. Therefore, the experimental results indicate that the combined DSA/GCMS technique is suitable for qualitative and quantitative analyses of hazelnut volatiles, and to support the sensory attributes in order to define hazelnut quality.