Characterization of odour active compounds in strawberry vinegars

Abstract

Odour-active compounds in strawberry vinegars were determined by gas chromatography equipped with an olfactometer using the modified frequency (MF) technique. The initial strawberry substrate was also analysed showing that ethyl 2-methylbutyrate, mesifurane, β-damascenone, furaneol and γ-decalactone were preserved during the double fermentation process, presenting high MF values. The final aromatic profile of strawberry vinegars is formed both by compounds from the substrate and by those formed during alcoholic and acetous fermentation. Due to their high MF, a total of 12 odour zones, identified as acetic, butyric and isovaleric acids, methional, 3-nonen-2-one, 2-phenylethanol, pantolactone + furaneol, p-vinylguaiacol, sotolon, phenylacetic acid and vanillin, were considered as possible impact odorants of strawberry vinegars. Finally, all potential impact odorants with similar sensory descriptors were grouped into eight categories, these being: fruity, sweet, grassy, spicy, butter–lactic–cheesy, chemical, empyreumatic and miscellaneous. According to the MF percentage of these categories, grassy, fruity, sweet and spicy aroma seem to have the highest influence on the overall impression of strawberry vinegars.