derivatives, benzenoids/phenylpropanoids, terpenoids, and nitrogen-containing compounds ( Table 1 ). Two monoterpenes, linalool and ( E )-β-ocimene, were predominant in floral volatiles for both species. Their emission rates were 11.2 and 4.0 μg·h −1 ·g −1
Yifan Jiang, Xinlu Chen, Hong Lin, Fei Wang, and Feng Chen
Kil Sun Yoo, Leonard M. Pike, and Brian K. Hamilton
A simple and fast method for measuring low boiling point (LBP) volatile terpenoids in carrots (Daucus carota L.) was developed by using a direct headspace sampling technique. Seven LBP terpenoid compounds were separated with high sensitivity and consistency via gas chromatography. High boiling point terpenoids above terpinolene were not well characterizable. Standard compounds showed highly linear responses up to 10 μg.g-1, with a detection limit of 0.01 μg.g-1. We confirmed that high α- and β-pinene and/or total terpenoids contributed to harsh or oily flavors. Up to 40 samples can be analyzed in an 8-h day using this method, compared to 10 samples using previous methods.
Ying Jia, Dianren Xia, and E.S. Louzada
A cDNA coding for a putative terpene synthase (Grtps) was isolated from `Rio Red' grapefruit (Citrus paradisi Macf.) mature fruit by differential display RT-PCR and the corresponding full-length cDNA and genomic clone were subsequently obtained. The isolated cDNA clone was 1644 bp in length encoding a protein of 548 amino acids with a predicted molecular mass of 64 kDa and of pI 5.38. The genomic clone was 3203 bp in length with 6 introns and 7 exons. This Grtps appears to be a sesquiterpene synthase based on molecular weight, genomic organization, and similarity with the other terpene synthases. Both RT-PCR and Northern blot expression analysis indicated that Grtps is not expressed in immature fruits, roots, or leaves, but only in mature fruits. Southern blot analysis of genomic DNA demonstrated that Grtps is one of the members in the family of terpene synthases.
P.W. Simon, C.E. Peterson, and W.H. Gabelman
Dong Sik Yang, Ki-Cheol Son, and Stanley J. Kays
acids in tomato play an important role in characterizing tomato flavor ( Goff and Klee, 2006 ). Several terpenoid compounds [e.g., camphene, p -cymene, δ -3-carene, α -humulene, limonene, linalool, ( E )- β -ocimene, α -pinene, β -thujone
John C. Beaulieu, Rebecca E. Stein-Chisholm, and Deborah L. Boykin
-Aldrich Fine Chemicals, Flavors and Fragrances Products [St. Louis, MO]}, according to Table 1 . Compound classes were defined and comprised of aldehydes (ALD), alcohols (OLS), esters (EST), ketones (ONE), furans (FUR), terpenoids (OID), and aromatics (ARO
Shea A. Keene, Timothy S. Johnson, Cindy L. Sigler, Terah N. Kalk, Paul Genho, and Thomas A. Colquhoun
composed of mixtures of volatile organic compounds (VOCs or volatiles) that are mostly lipophilic liquids with high vapor pressures at ambient temperatures ( Pichersky et al., 2006 ). Floral volatiles typically fit in the families of terpenoids
Solveig J. Hanson and Irwin L. Goldman
flavor: geosmin, sucrose, oxalate, and saponins. Earthy aroma, conferred by the volatile terpenoid geosmin ( Gerber, 1967 ), is identified as the signature flavor of table beet ( Goldman and Navazio, 2003 ) but can be unpalatable in excess ( Tyler et al
Carlos A. Lazcano, L.M. Pike, and K.S. Yoo
A new designer carrot, `BetaSweet', with high levels of anthocyanin, betacarotene, and crispy texture was developed by the Vegetable Improvement Center at Texas A&M Univ. The new carrot contained low levels of low-volatile terpenoids, responsible for the harsh flavor in carrots and high levels of reducing sugars. Carotenoid content increased with carrot maturity and stabilize at 120 days after sowing for orange and maroon genotypes; however, the maroon genotype was 35% higher than the orange cultivar. Anthocyanin, a cancer preventive compound and not detected in ordinary orange carrots, is present in `BetaSweet' maroon carrot with 89.8 mg·100 g-1 of fresh weight. High percentage of soluble solids and succulence in the maroon cultivar seemed to contribute to the favored sweetness perception by consumers. A consumer taste panel showed a significant difference between orange and maroon genotype for sweetness, texture, and overall carrot flavor.
Leonard M. Pike
`BetaSweet' is a new “designer” carrot that was conceived as a research project with the objective to create a new high-quality vegetable with unique characteristics. The gene responsible for purple or maroon color in carrots is a natural one and has been around for many years. Carrot breeders have discarded carrots which occasionally segregated to this color because orange has been the preferred traditional color. In 1989, three carrots grown from Brazilian seed were observed to have a blotchy maroon color mixed with the normal orange. Within two generations of breeding effort I had obtained a few carrot roots with near complete maroon exterior color and orange interior. The contrast of orange and maroon was very attractive in carrots cut as coins or sticks. The maroon and orange color would serve as the perfect way to identify and promote this new variety. Several additional generations were required using extensive laboratory testing for low terpenoids (strong carrot flavors), high sugars, high carotene, and crispy texture. Thousands of carrot roots were analyzed and selected for those qualities and for the dark maroon exterior and orange interior colors. The few best for those characteristics were intercrossed, and reselected for their adaptation when grown under Texas climatic conditions.