Validation of gas chromatography olfactometry results for 'gala' apples by evaluation of aroma-active compound mixtures

摘要

'Gala' is an early maturing apple variety with a distinctive aroma and flavor. Previous research has determined 'Gala's aroma-active compounds by using Osme, a gas chromatography olfactormetry method that records subjects' olfactory response on a time-intensity scale. Sixteen of those compounds were combined in mixtures in water solutions at concentrations determined by analyzing apple headspace. Sixteen panelists compared aromas of the solutions with fresh apples and rated degree of difference for aroma. In a pilot study, mixture solutions were prepared by combining compounds based on their intensities as perceived by Osme; results showed a large variability between panelists for perception of the solutions. Another experiment used a statistical screening design. Hexyl acetate, hexanal, butyl acetate, 2-methyyl butyl acetate, and methyl-2-methyl butyrate contributed to the least difference between mixtures and apples; while pentyl. acetate, hexyl-2methyl butyrate, butyl hexanoate, and 4-allyl anisole contributed to the largest difference. Further experiments using statistical designs will be necessary to determine interactions between compounds.