Submitted to: Subtropical Technology Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 9/4/2007
Publication Date: 10/18/2007
Citation: Kerbiriou, P., Plotto, A., Goodner, K.L., Baldwin, E.A., Gmitter, F. 2007. Quality evaluation of tangerines from the CREC breeding program. Subtropical Technology Conference Proceedings. 58:14-15.
Technical Abstract: A quality evaluation of tangerines from the CREC breeding program was undertaken in 2006-2007. Forty five tangerine hybrids and 10 named commercial cultivars were sampled from November 2006 to March 2007. Some samples were harvested multiple times over the season. Fruit were washed, sanitized, and carefully juiced to avoid incorporating peel oil volatiles into the juice. Juice was frozen for volatile, titratable acidity, carotenoid and sugar analyses as well as for sensory evaluation. Data from gas chromatography mass-spectrometry revealed that while about 50 compounds were found in 75% of the samples, 96 compounds were found in less than 25% of the samples, and might be more variety specific. A cluster analysis based on presence/absence of volatiles revealed ten main clusters influenced by harvest date and/or progenitors, highlighting relationships among certain hybrids based on their volatile composition. Cluster 2 mainly grouped samples having 'Fallglo' and 'Fairchild' in their parentage, while cluster 4 mainly grouped samples having a common parent 'Murcott'. Cluster 10 grouped samples having sweet oranges in their genetic background and being rich in esters, which are known to give a fruity note to orange juice. This method provided useful information on tangerine hybrid volatile content in relation to their genetic make-up. Juice soluble solids, titratable acidity, and solids/acids ratio ranged 9.3-16.3% SSC, 0.119-1.675% citric acid, and ratios 7.4-116.8, respectively, with average 12.2 °Brix, 0.932% citric acid, and 15.4 solids/acids ratio. A panel was trained and defined 17 descriptors for aroma, flavor and taste. Descriptors were sulfury aroma, tangerine, orange, grapefruit, fruity non-citrus, floral, green/fatty aroma and flavor, sweet, sour, bitter taste, and aftertaste. Panelists smelled and tasted thawed juice in a completely randomized design, 5 juices per session. A multivariate analysis showed separation among hybrids based on green/fatty, sulfury, tangerine, and [orange, fruity, floral] aroma descriptors, and on sour, tangerine, [sweet, orange, fruity, floral], and [green/fatty, grapefruit, bitter, aftertaste] flavor descriptors. Panelists could distinguish samples harvested multiple times from the same tree by increasing sweetness or decreasing sourness with later harvests. Data are being analyzed to identify correlations between instrumental and sensory data. This study showed the wide variation in aroma and taste attributes in tangerine hybrids from the CREC breeding program. More sensory analysis will be performed on tangerine juice, but also, taste panels will be performed using whole fruit during the 2007-2008 season.