Abstract
While orange juice volatile composition has been well studied, little is known about volatiles in tangerines. This study was undertaken to determine the most common compounds present in 56 tangerine hybrids, and to find relationships among these hybrids based on volatile content. Fruits were harvested from Nov. 2006 to Mar. 2007. A composite sample of juice from approximately 20 fruits was analyzed by gas chromatography mass-spectrometry. Among the more than 200 identified volatiles in total, ethanol, a-pinene, cymene, and d-limonene were found in all the samples. These compounds were previously reported in citrus products (essence, peel oil, juice, etc.). A principal component analysis showed that hybrids 9-1, 8-10, and 'Hongju' were different from the others because a larger than average number of volatiles was detected in those samples. A cluster analysis based on presence/absence of volatiles revealed 10 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 juices. This method provided useful information on tangerine hybrid volatile content in relation to their genetic makeup.
