Descriptive sensory analysis combined with a chemical analysis, provided insight regarding sensory significance for a better understanding of berrycactus' flavor. This study was based on the volatile components derived from the gas chromatography-olfactometry (GC-O) analysis. Four different ripening stages were used for the experiments: unripe, red, transition, and over-ripe. Besides red and transition stages were stored in sealed plastic bags for 7 d at 5 °C as an additional treatment in order to establish comparisons with fresh samples. GC-O analysis was performed following OSME (time-intensity) method. Moreover, chemical characterization was achieved through GC-MS analysis, each compound was tentatively identified by comparing its mass spectra with the spectra from the library NIST02, by its aroma notes and Kovats Index. The aroma descriptors found were: caramel, fruity, acetic acid, fresh, citrus, floral, and phenolics. Nine volatile compounds are among the most important in flavor of berrycactus: furfural, 5-methyl-2-furancarboxaldehyde, 2(5H)-furanone, 5-acetoxymethyl-2-furaldehyde, 2-cyclohexen-1-ol, octanoic acid ethyl ester, decanoic acid ethyl ester, octanoic acid, and phenylethyl alcohol. To better reflect the real responses of these compounds, the regression analysis of concentrations to ripening stages were performed. The 2,3-dihydro-3,5-dihydroxy-6-methyl-(4H)-pyran-4-one was found in berrycactus, it has been reported in chemical profile of other berries as a product of heat-induced reactions, however, this compound has no aroma activity. The data suggest that both furanones and esters contribute to the aroma of berrycactus. On the other hand, solid phase microextraction was found to be more useful in detecting esters and acids whereas solvent extraction was more effective in detecting furanones and ketones.
Practical application: This information could contribute to setting up favorable processing conditions; in order to retain the best sensory characteristics of berrycactus along with functional properties that would enhance commercialization and exploitation of this fruit and to promote berrycactus cultivation programs.
© 2012 Institute of Food Technologists®