ARS | Publication request: Characterization of aroma volatiles in select tangerine hybrids by gas chromatography-olfactometry

Submitted to: Subtropical Technology Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: October 18, 2009
Publication Date: October 22, 2009
Citation: Miyazaki, T., Plotto, A., Baldwin, E., Reyes De Corcuera, J., Gmitter, F. 2009. Characterization of aroma volatiles in select tangerine hybrids by gas chromatography-olfactometry. Subtropical Technology Conference Proceedings. 60:20.

Technical Abstract: Aroma volatiles in orange juice have been well studied1 but little information is available on those found in fresh tangerine. Five of 25 tangerine hybrids studied in the 2007-2008 season were analyzed by gas chromatography-olfactometry (GC-O) using the time intensity (Osme) method. The choice of samples to analyze by GC-O was determined from their differences by sensory evaluation in a trained panel2 and from their volatile profile. Fruit were harvested and gently squeezed to avoid peel oil volatiles in the juice. Aliquot samples (2.5 mL) were put into 20 mL GC vials with an equal volume of saturated sodium chloride to stop any potential enzymatic activity. Aroma volatiles were sampled using headspace solid phase microextraction (SPME) method, and analyzed by GC-mass spectrometry (GC-MS) and GC-O. Three panelists evaluated the samples by GC-O. Forty nine odorants were found by all three panelists in a consensus and comprised of monoterpenes, aldehydes, esters, alcohols, ketones, a phenol (thymol) and an ether (1,8-cineole). Hexanal, ethyl 2-methylbutanoate, unknown peak (No. 9), 1-octen-3-one, ß-myrcene, 1,8-cineole, linalool, and (E,E)-2,4-nonadienal with descriptors of green/grassy, fruity, metallic, mushroom, metallic, green, floral and fatty, respectively, were intense aroma compounds in all five samples. Differences between sample aroma profiles were found for compounds having descriptors of fruity, green/metallic/fatty, terpeney and green/grassy as the main notes, and five other aroma categories. Perceived aroma intensity determined the specific aroma character of each sample. GC-O results partially confirmed the sensory characteristics of some samples (8-9 × Val4x with orange aroma and a sample with undetermined parentage having characteristic pumpkin and fatty aroma and flavor); however, sugars, acids and other non-volatile compounds also contribute to flavor.