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.
Ying Jia, Dianren Xia, and E.S. Louzada
Andrew G. Reynolds, Douglas A. Wardle, and Marjorie Dever
Vitis vinifera L. cultivars Müller-Thurgau, Muscat Ottonel, Gewürztraminer, and Kerner were studied for 1 year to document changes in fruit terpene levels from berry stage to free-run and press-juice stages. Substantial amounts of free volatile terpenes (FVTs) and potentially volatile terpenes (PVTs) were lost between berry and juice stages. PVTs were higher in press juices of `Gewürztraminer' and `Muscat Ottonel' than in free-run juices. In another experiment, juices from `Miiller-Thurgau', `Muscat Ottonel', `Kerner', `Optima', `Pearl of Csaba', and `Siegerrebe', harvested 10 to 20 days after a designated initial harvest date, contained higher FVTs and PVTs than initially. A third experiment with `Kerner', `Müller-Thurgau', `Optima', and `Siegerrebe' found highest FVTs and PVTs in juices from grapes subjected to skin contact compared with grapes crushed and immediately pressed. Sensory evaluation showed aroma differences between wines from free-run and press juices of `Miiller-Thurgau' and `Muscat Ottonel', aroma and flavor differences due to harvest date for all cultivars except `Pearl of Csaba', and aroma and flavor differences due to skin contact for `Siegerrebe'.
Fredy Van Wassenhove, Patrick Dirinck, Georges Vulsteke, and Niceas Schamp
A two-dimensional capillary gas chromatographic method was developed to separate and quantify aromatic volatiles of celery in one analysis. The isolation, identification, and quantification of the volatile compounds of four cultivars of blanching celery (Apium graveolens L. var. dulce) and six cultivars of celeriac (Apium graveolens L. var. rapaceum) are described. The qualitative composition of Likens-Nickerson extracts of both cultivars is similar. The concentration of terpenes and phthalides, the key volatile components, found in various cultivars of both celery and celeriac varied over a wide range.
R.J. Bender, J.K. Brecht, E.A. Baldwin, and T.M.M. Malundo
To determine the effects of fruit maturity, storage temperature, and controlled atmosphere (CA) on aroma volatiles, mature-green (MG) and tree-ripe (TR) `Tommy Atkins' mangoes (Mangifera indica L.) were stored for 21 days in air or in CA (5% O2 plus 10% or 25% CO2). The MG fruit were stored at 12 °C and the TR fruit at either 8 or 12 °C. Homogenized mesocarp tissue from fruit that had ripened for 2 days in air at 20 °C after the 21-day storage period was used for aroma volatile analysis. The TR mangoes produced much higher levels of all aroma volatiles except hexanal than did MG fruit. Both MG and TR mangoes stored in 25% CO2 tended to have lower terpene (especially p-cymene) and hexanal concentrations than did those stored in 10% CO2 and air-stored fruit. Acetaldehyde and ethanol levels tended to be higher in TR mangoes from 25% CO2 than in those from 10% CO2 or air storage, especially at 8 °C. Inhibition of volatile production by 25% CO2 was greater in MG than in TR mangoes, and at 8 °C compared to 12 °C for TR fruit. However, aroma volatile levels in TR mangoes from the 25% CO2 treatment were in all cases equal to or greater than those in MG fruit treatments. The results suggest that properly selected atmospheres, which prolong mango shelf life by slowing ripening processes, can allow TR mangoes to be stored or shipped without sacrificing their superior aroma quality.
Denys J. Charles and James E. Simon
Essential oils were extracted from leaves, flowers, and stems of Ocimum basilicurn, O. kilimandscharicum, and O. micranthum by solvent extraction, hydrodistillation, and steam distillation for essential oil content and the oil analyzed by GC and GC/MS for composition. While the yield of essential oil was consistently higher from steam distillation than hydrodistillation, a similar number of compounds was recovered from both hydrodistillation and steam distillation. Though the relative concentration of the major constituents was similar by both methods, the absolute amounts were higher with steam distillation. Essential oil content and composition varied by plant species and plant part. Essential oil content was highest in flowers for O. basilicum and in leaves for O. micranthum. No significant differences were observed in essential oil yield and relative concentration of major constituents using fresh or dry samples and using samples from 75 g to 10 g of dry plant tissue. While minor differences between hydrodistillation and steam distillation were observed, both methods resulted in high yields and good recovery of essential oil constituents. Hydrodistillation is a more-rapid and simpler technique than steam and permits the extraction of essential oil where steam is not accessible.
Juan J. Polari, Louise Ferguson, and Selina C. Wang
aroma. Volatile terpenes are the key components for their aroma, being the major compounds in raw kernels limonene, α-pinene and β-myrcene ( Kendirci and Onoǧur, 2011 ; Rodríguez-Bencomo et al., 2015 ). In California, pistachios are the third most
Jian-rong Feng, Wan-peng Xi, Wen-hui Li, Hai-nan Liu, Xiao-fang Liu, and Xiao-yan Lu
high level of terpenes ( Fig. 1B ). ‘Danxing’, ‘Sumaiti’, and ‘Kumaiti’ were clustered into group C ( Fig. 1A ) and were characterized by high levels of aldehydes and alcohols ( Fig. 1B ). These changes are consistent with the GC-MS results. Fig. 1
Dave Hawley, Thomas Graham, Michael Stasiak, and Mike Dixon
bud has a relatively high density of glandular trichomes rich in cannabinoids and terpenes that are of medicinal and recreational interest ( Happyana et al., 2013 ). There are relatively few peer-reviewed studies on optimizing environmental parameters
Chunyu Zhang, Xuesen Chen, Hongwei Song, Yinghai Liang, Chenhui Zhao, and Honglian Li
volatile compounds released by M. baccata and M. prunifolia fruit. We identified 58 and 54 volatile compounds, including alcohols, esters, aldehydes, terpenes, hydrocarbons, ethers, heterocycles, carboxylic acids, and ketones, in 10 M. baccata
James J. Polashock, Robert A. Saftner, and Matthew Kramer
are primarily aldehydes and terpenes ( Baloga et al., 1995 ; Overton and Manura, 1999 ). Aldehydes, organic compounds containing a terminal carbonyl (-CHO) group, are often derived from lipid peroxidation ( Latrasse, 1991 ). Terpenes, primarily plant