•A novel method for the analysis of mousy off-flavour compound in wine was developed.•Only filtration and basification were required prior to HPLC-MS/MS analysis.•The method was simple and rapid as ...well as highly reliable and robust.•LOQ was 0.23 μg L−1 for both red and white wine.
2-Acetyltetrahydropyridine (ACTPY), tautomers of 2-acetyl-1,4,5,6-tetrahydropyridine and 2-acetyl-3,4,5,6-tetrahydropyridine, is reported as one of the major compounds responsible for mousy off-flavour wine. A simple and rapid method for the quantitation of ACTPY in wine using HPLC-APCI-MS/MS was developed. Only filtration and basification were required for sample preparation prior to analysis. The analytical run time was approximately 17 min for one sample. Precision and accuracy tests confirmed that the method was highly reliable and robust. Limits of quantitation (LOQ) for red and white wines were estimated to be 0.23 μg L−1, which was sufficiently sensitive to allow the quantitation of ACTPY at its odour threshold level in water. The method can be implemented for routine objective screening of wines for mousy off-flavour, to determine sensory threshold levels in wine and to aid further research aiming to reduce the occurrence of this fault in wine.
•A simple, robust and reliable method was developed for measuring phthalates in wine.•HPLC–MS/MS was practically used for wine phthalate analysis.•No effect of HPLC phthalate contamination on ...analysis was confirmed.•Extraction and enrichment were not required for sample preparation.
This paper describes the development and application of a novel method for the analysis of phthalates in wine using HPLC–MS/MS combined with a hold-back column. Phthalates are ubiquitous contaminants in the environment and can be widely found in laboratory materials and equipment. A HPLC system is no exception and can be the source of contamination affecting the accuracy and precision of analytical results. The new method successfully separates phthalates from the different sources, a wine sample and HPLC system by a simple technique using an additional HPLC column (a hold-back column) placed upstream of the injection valve. The hold-back column effectively retains the HPLC-derived contaminants during column equilibrium time and delays their elution times from an analytical column. Consequently, a phthalate from a wine sample can be baseline separated as it elutes sufficiently earlier than the same phthalate from the HPLC system. HPLC–MS/MS analysis combined with the hold-back column demonstrated virtually no influence of the HPLC contaminants on the quantification of phthalates present in wine. Together with a simple and rapid sample preparation and the use of labeled internal standards, the method was confirmed to be robust and reliable to determine concentrations of phthalates in wine. Quantification limits were within the range of 1.6–9.8μgL−1 for dimethyl, diethyl, dibutyl, benzylbutyl, bis(2-ethylhexyl) and dioctyl phthalates, and 7.5–26.6μgL−1 for multiple isomeric phthalates, di-iso-nonyl and di-iso-dodecyl phthalates.
The first finding of low‐temperature eclogites from the Indochina region is reported. The eclogites occur along the Song Ma Suture zone in northern Vietnam, which is widely regarded as the boundary ...between the South China and Indochina cratons. The major lithology of the area is pelitic schist that contains garnet and phengite with or without biotite, chloritoid, staurolite and kyanite, and which encloses blocks and lenses of eclogite and amphibolite. The eclogites commonly consist of garnet, omphacite, phengite, rutile, quartz and/or epidote with secondary barroisite. Omphacite is commonly surrounded by a symplectite of Na‐poor omphacite and Na‐rich plagioclase. In highly retrograded domains, diopside + tremolite + plagioclase symplectites replace the primary phases. Estimated peak‐pressure metamorphic conditions based on isochemical phase diagrams for the eclogites are 2.1–2.2 GPa and 600–620 °C, even though thermobarometric results yield higher pressure and temperature conditions (2.6–2.8 GPa and 620–680 °C). The eclogites underwent a clockwise P–T trajectory with a post‐peak‐pressure increase of temperature to a maximum of >750 °C at 1.7 GPa and a subsequent cooling during decompression to 650 °C and 1.3 GPa, which was followed by additional cooling before close‐to‐isothermal decompression to ∼530 °C at 0.5 GPa. The surrounding pelitic schist (garnet–chloritoid–phengite) records similar metamorphic conditions (580–600 °C at 1.9–2.3 GPa) and a monazite chemical age of 243 ± 4 Ma. A few monazite inclusions within garnet and the cores of some zoned monazite in garnet–phengite schist record an older thermal event (424 ± 15 Ma). The present results indicate that the Indochina craton was deeply (>70 km) subducted beneath the South China craton in the Triassic. The Silurian cores of monazite grains may relate to an older non‐collisional event in the Indochina craton.
Background and Aims
An elevated concentration of several volatile phenols and their glycosides in grapes and wines is associated with exposure of grapes to forest fire smoke. Interpretation of phenol ...compositional data from grapes or wines, however, is complicated by the fact that traces of these compounds can be detected in non‐smoke‐exposed samples. Hence, the concentration of smoke marker compounds was investigated with the aim of providing a reference data set to help determine smoke exposure.
Methods and Results
Thirteen phenolic compounds were measured in non‐smoke‐exposed grape berries and unoaked wines made from 12 cultivars collected from multiple regions across Australia over four vintages. The grapes and wines contained a low concentration of several volatile phenols and their glycosides. These varied in concentration between cultivars but showed little variation between regions and vintages. The maximum concentration observed for any analyte was below 15 μg/kg in grapes and approximately 15 μg/L in wine.
Conclusions
The results for smoke marker compounds should be considered on a per‐cultivar basis when determining smoke exposure. Interpretation of results for a potentially smoke‐exposed sample can be achieved based on comparison with the 99th percentile values reported here. Use of the interpretation system described should be limited to determining smoke exposure and not smoke taint.
Significance of the Study
This study provides a comprehensive set of data that defines the upper limits of smoke marker compounds expected in Australian grapes and wines from non‐smoke‐exposed vineyards that can be used for determining the likelihood of smoke exposure.
Background and Aims. Smoke exposure occurred in the Adelaide Hills region in December 2019 due to a wildfire, when wine grapes were peppercorn-size green berries. Previously, pre-veraison smoke ...exposure had been identified through model experiments as unlikely to affect grape composition, whereas smoke exposure after veraison can have a major effect on wine flavour. Hence the effects of pre-veraison smoke on grape and wine composition, and smoky sensory properties of wine were investigated. Methods and Results. Chardonnay, Pinot Noir and Shiraz were investigated and eight blocks with varied smoke exposure were selected for each cultivar. Berries were sampled initially four weeks after the fire and at harvest, and mature grapes were made into unoaked wines. Established smoke exposure markers, phenolic glycosides, were found in berries at pre-veraison and at harvest from the high smoke exposure sites, with concentrations well above those found in non-smoke exposed fruit. Volatile phenols were also elevated in grapes at harvest. The resulting red wines from some exposure vineyards were high in volatile phenols, glycosides and smoky flavours. However, most of the Chardonnay wines expressed much less smoky flavours, despite similar levels of smoke exposure of grapes. Conclusions. Pre-veraison smoke exposure can result in elevated concentrations of volatile phenols and their glycosidic metabolites in grape berries and wine and cause strong smoky flavour in wine. Significance. The wine sector and land management agencies responsible for controlled burns need to consider the effect of smoke from fires near vineyards even very early in the growing season.
Objective
The selective reporting of favorable outcomes has a serious influence on our evidence base. However, this problem has not yet been systematically investigated in the field of psychiatry. ...Our study aimed to evaluate registration and outcome reporting in randomized controlled trials (RCTs) of standard treatments for depression: cognitive behavioural therapy (CBT) or new‐generation antidepressants (ADs).
Method
We searched for reports of RCTs examining the efficacy of CBT or AD for depression that were published between 2011 and 2013. We then compared their primary outcomes in the trial registries and those in publications.
Results
We identified 170 trials. Among them, 92 trials (54.1%) were registered, 43 trials (25.3%) were properly registered, and only 32 (18.8%) trials were both properly registered and reported (the primary outcomes as recorded in the registries were reported in publications). There was no statistically significant difference in the proportions of properly registered and reported trials for CBT or AD (relative risk: 0.51, 95% CI: 0.25–1.03). High impact factor journals, commercial funding, publication of protocol, and relatively large sample size were significant predictors of proper registration and reporting.
Conclusion
The prevalence of proper registration and reporting is still very low in depression trials.
Objective
In modern psychiatry, depression is diagnosed with the diagnostic criteria; however, the trajectory of each of the criterion symptoms is unknown. This study aims to examine this.
Methods
We ...made repeated assessments of the nine diagnostic criterion symptoms with the Patient Health Questionnaire‐9 (PHQ‐9) among 2011 participants of a 25‐week pragmatic randomised controlled trial of sertraline and/or mirtazapine for hitherto untreated major depressive episodes. The changes from baseline were estimated with the mixed‐effects model with repeated measures. The time to disappearance of each symptom was modeled using the Kaplan–Meier survival analysis.
Results
The total score on PHQ‐9 was 18.5 (SD = 3.9, n = 2011) at baseline, which decreased to 15.3 (5.2, n = 2011) at week 1, to 11.5 (5.9, n = 1953) at week 3, to 7.8 (6.0, n = 1927) at week 9, and to 6.0 (5.9, n = 1910) at week 25. Suicidal ideas, psychomotor symptoms decreased rapidly, while anergia and sleep disturbance also decreased but only slowly. The survival analyses confirmed the primary analyses.
Conclusions
Upon initiation of antidepressant treatment, patients with newly treated major depressive episodes can expect their suicidal ideas and psychomotor symptoms to disappear first but sleep disturbances and anergia to linger on.
BACKGROUND AND AIMS: Exposure to smoke and uptake of taint imparting phenols in grapes and wines is a significant problem in bushfire‐prone regions of Australia and other countries. The effects of ...smoke exposure on taint occurrence in wines, however, can be variable. This study assessed the influence of cultivar on uptake and accumulation of smoke‐borne phenols in grapes and of subsequent processing and winemaking methods on extraction of phenols into wines. METHODS AND RESULTS: Smoke‐exposure experiments were conducted in commercial vineyards of Chardonnay, Merlot and Sauvignon Blanc 14 days after the onset of veraison. At maturity, grapes were harvested for winemaking, which included malolactic fermentation (MLF) for Merlot. Volatile and glycoconjugated phenols were determined in grapes and the resultant wines. All cultivars had a similar concentration of smoke‐derived total phenols in their grapes. The apparent extraction of total phenols from grapes into wines, however, differed markedly among the three traditional winemaking methods. Red winemaking (Merlot) with skin contact extracted 88% of total grape phenols, whereas white winemaking either by crushing before pressing (Sauvignon Blanc) or by whole‐bunch pressing without crushing (Chardonnay), respectively, released 39 and 18% of total phenols. For Merlot wines, MLF did not affect the extraction of total smoke‐derived phenols. CONCLUSIONS: Under standardised exposure conditions (duration, intensity and phenology), the three cultivars studied accumulated a similar concentration of total phenols in grapes. The grape‐processing and winemaking methods, however, can bring about a fourfold difference in the concentration of total phenols of wines. The smoke‐derived phenols extracted from grapes into wine and the distribution of these phenols between the volatile and conjugated pools were not affected by MLF. SIGNIFICANCE OF THE STUDY: The key findings reported here have the potential to improve decision‐making by grapegrowers and winemakers on the effect of cultivar and winemaking practice on potential smoke taint in wine.
The presence of the β-
d-glucopyranoside of guaiacol (glucoside) in juice of grapes following grapevine exposure to smoke was investigated. The glucoside was synthesized as a reference compound and ...an HPLC–MS/MS method was developed for its detection in juice. The glucoside was found in the juice extracts of grapes exposed to bushfire smoke, as well as grapes experimentally exposed to smoke. Compared to the control (unsmoked) juice sample, the experimentally smoked juice contained a significant amount of the glucoside, indicating glucosylation of guaiacol occurred following grapevine smoke exposure. The reference compound, and the glucoside found in the smoked juice samples were less susceptible to acid treatment but virtually disappeared after enzyme treatment with β-glucosidase. The susceptibility of the glucoside to enzyme hydrolysis could be one reason for the release of guaiacol from smoke affected grapes during fermentation.
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