Evaluation of volatile flavour compounds from cashew apple (Anacardium occidentale L) juice by the Osme gas chromatography/olfactometry technique

The headspace volatile components of the juice of cashew apples from a commercial Brazilian dwarf genotype were separated by high-resolution gas chromatography and identified by GC/MS. Five judges evaluated the GC effluents using the Osme technique in order to determine the importance of each compound to the characteristic cashew aroma. Esters methyl 3-methyl butanoate, ethyl 3-methyl butanoate, methyl butanoate, ethyl butanoate, ethyl trans-2-butenoate and methyl 3-methyl pentanoate were important to the sweet, fruity and cashew-like aroma. Cis-3-hexenol, hexanal and 2-methyl-2-pentenal presented different green notes. In spite of the flame ionisation detector being unable to detect sulphur compounds, the olfactometric analysis revealed chromatographic regions where sulphur-like odours were perceived by the Osme sensory panel. The most intense unpleasant odour was due to 2-methyl butanoic acid, which was described as very stinky. The sensory panel showed good olfactory sensitivity and reproducibility. Sensory and instrumental data correlation allowed a greater understanding of the role of several volatile compounds in the sensory quality of the juice.