1.Grapevine bunch rots: impacts on wine composition, quality, and potential procedures for the removal of wine faults.
Steel CC1, Blackman JW, Schmidtke LM. J Agric Food Chem. 2013 Jun 5;61(22):5189-206. doi: 10.1021/jf400641r. Epub 2013 May 28.
Bunch rot of grape berries causes economic loss to grape and wine production worldwide. The organisms responsible are largely filamentous fungi, the most common of these being Botrytis cinerea (gray mold); however, there are a range of other fungi responsible for the rotting of grapes such as Aspergillus spp., Penicillium spp., and fungi found in subtropical climates (e.g., Colletotrichum spp. (ripe rot) and Greeneria uvicola (bitter rot)). A further group more commonly associated with diseases of the vegetative tissues of the vine can also infect grape berries (e.g., Botryosphaeriaceae, Phomopsis viticola ). The impact these fungi have on wine quality is poorly understood as are remedial practices in the winery to minimize wine faults. Compounds found in bunch rot affected grapes and wine are typically described as having mushroom, earthy odors and include geosmin, 2-methylisoborneol, 1-octen-3-ol, 2-octen-1-ol, fenchol, and fenchone. This review examines the current state of knowledge about bunch rot of grapes and how this plant disease complex affects wine chemistry.
2.Recent developments in the analysis of musty odour compounds in water and wine: A review.
Callejón RM1, Ubeda C2, Ríos-Reina R1, Morales ML1, Troncoso AM3. J Chromatogr A. 2016 Jan 8;1428:72-85. doi: 10.1016/j.chroma.2015.09.008. Epub 2015 Sep 5.
One of the most common taints in foods is a musty or earthy odour, which is commonly associated with the activity of microorganisms. Liquid foods, particularly wine and water, can be affected by this defect due to the presence of certain aromatic organic compounds at very low concentrations (ng/L) consistent with human threshold perception levels. The volatile compounds responsible for a mouldy off-aroma include approximately 20 compounds, namely, haloanisoles, geosmin, 2-methylisoborneol, several alkyl-methoxypyrazines, 1-octen-3-ol, 1-octen-3-one, trans-octenol, 3-octanone, fenchol and fenchone. Methods for determining these very low concentrations of odour compounds must be extremely sensitive and selective with efficient preconcentration treatments. A number of extraction techniques based on LLME (liquid-liquid microextraction), SPME (solid-phase microextraction) or SBSE (stir-bar sorptive extraction) can be applied and should be selected on a case-by-case basis.
3.Inhibitory effects of monoterpenes on human TRPA1 and the structural basis of their activity.
Takaishi M, Uchida K, Fujita F, Tominaga M. J Physiol Sci. 2014 Jan;64(1):47-57.
TRPA1, one of the transient receptor potential channels, has been reported to be involved in nociception and inflammatory pain, suggesting that this molecule could be a promising target for the development of analgesic agents. We screened several monoterpene analogs of camphor, which is known to inhibit human (h) TRPA1, to identify more effective naturally occurring TRPA1 antagonists. Borneol, 2-methylisoborneol, and fenchyl alcohol exhibited higher inhibitory effects on hTRPA1 activity than either camphor or 1,8-cineole. Our results revealed further that the S873, T874, and Y812 residues of hTRPA1 were involved in the inhibitory effects, suggesting that the hydroxyl group in the six-membered ring of the inhibitors may be interacting with these amino acids. Further research on these identified TRPA1 antagonists could lead to new pain therapeutics.
4.Gas chromatography-mass spectrometry method optimized using response surface modeling for the quantitation of fungal off-flavors in grapes and wine.
Sadoughi N1, Schmidtke LM1, Antalick G1, Blackman JW1, Steel CC1. J Agric Food Chem. 2015 Mar 25;63(11):2877-85. doi: 10.1021/jf505444r. Epub 2015 Mar 17.
An optimized method for the quantitation of volatile compounds responsible for off-aromas, such as earthy odors, found in wine and grapes was developed. The method involved a fast and simple headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) for simultaneous determination of 2-isopropyl-3-methoxypyrazine, 2-isobutyl-3-methoxypyrazine, 3-octanone, fenchone, 1-octen-3-one, trans-2-octen-1-ol, fenchol, 1-octen-3-ol, 2-methylisoborneol, 2,4,6-trichloroanisole, geosmin, 2,4,6-tribromoanisole, and pentachloroanisole. The extraction of the temperature and time were optimized using response surface methodology in both wine base (WB) and grape base (GB). Low limits of detection (0.1-5 ng/L in WB and 0.05-1.6 in GB) and quantitation (0.3-17 in WB and 0.2-6.2 in GB) with good recoveries (83-131%) and repeatability [4.3-9.8% coefficient of variation (CV) in WB and 5.1-11.1% CV in GB] and reproducibility (3.6-10.