Although smoke exposure has been associated with the development of smoke taint in grapes and subsequently in wine, to date there have been no studies that have demonstrated a direct link. In this study, postharvest smoke exposure of grapes was utilized to demonstrate that smoke significantly influences the chemical composition and sensory characteristics of wine and causes an apparent 'smoke taint'. Verdelho grapes were exposed to straw-derived smoke for 1 h and then fermented according to two different winemaking treatments. Control wines were made by fermenting unsmoked grapes. Sensory studies established a perceivable difference between smoked and unsmoked wines; smoked wines were described as exhibiting 'smoky', 'dirty', 'earthy', 'burnt' and 'smoked meat' characteristics. Quantitative analysis, by means of gas chromatography-mass spectrometry, identified guaiacol, 4-methylguaiacol, 4-ethylguaiacol, 4-ethylphenol, eugenol, and furfural in each of the wines made from smoked grapes. However, these compounds were not detected in the unsmoked wines, and their origin is therefore attributed to the application of smoke. Increased ethanol concentrations and browning were also observed in wines made from grapes exposed to smoke.
Background and Aims: Grapevine smoke exposure has been reported to produce smoke aromas in wine, resulting in 'smoke taint'. This study describes the application of smoke to field-grown grapevines between veraison and harvest to investigate the effect of timing and duration of smoke exposure on wine composition and sensory attributes. Methods and Results:Smoke was applied to grapevines as either a single smoke exposure to different vines at veraison or at 3, 7, 10, 15, 18 or 21 days post-veraison or repeated smoke exposures to the same vines at veraison and then at 3, 7, 10, 15, 18 and 21 days post-veraison. Gas chromatography-mass spectrometry analysis of guaiacol, 4-methylguaiacol, 4-ethylguaiacol and 4-ethylphenol showed elevated levels in all wines produced from fruit from smoked grapevines. Repeated smoke exposures had a cumulative effect on the concentration of these compounds. A trained sensory panel identified the aromas of 'burnt rubber', 'smoked meat', 'leather' and 'disinfectant' in all wines derived from smokeexposed grapevines but not in control wines. Conclusions: Smoke application to field-grown grapevines between veraison and harvest can influence the accumulation of volatile phenols and intensity of smoke aromas in resultant wines. A peak period of vine sensitivity to smoke at 7 days post-veraison is identified. Repeated smoke exposures have a cumulative effect. Significance of the Study: This is the first study to report the deliberate and controlled smoke application to field-grown grapevines demonstrating the timing and duration of smoke exposure to significantly affect wine chemical and sensory characters. AbbreviationsBET best estimate threshold; FAN free amino nitrogen; GC-MS gas chromatography-mass spectrometry; PCA principal component analysis; TSS total soluble solids.
Background and Aims: Smoke exposure of grapevines and development of smoke taint in wine are issues of increasing incidence and severity. There is limited understanding of the effect of phenological stage at the time of smoke exposure on taint development. The aim of this study was to demonstrate the variation in smoke uptake and taint development between and within seasons. Methods and Results:Smoke was applied to field-grown Merlot grapevines at 12 stages of vine development over three growing seasons. Key periods of vine sensitivity to smoke taint in wine were (i) from shoots at 10 cm to full bloom (low levels of smoke taint); (ii) from berries at pea size to the onset of veraison (variable levels of smoke taint); and (iii) between 7 days post-veraison and harvest (high levels of smoke taint). Conclusions:The severity of taint in wine varied depending on the phenological timing of grapevine smoke exposure. Taint was elevated when exposure occurred between 7 days post-veraison and harvest. The carry-over of smoke constituents the following season was not detectable in wine but yields were reduced. Significance of the Study: This is the first study to demonstrate the timing of smoke exposure to critically affect wine chemical and sensory characters. These effects were consistent and reproducible over three seasons.
The aim of this study was to investigate the effect of diets supplemented with fish oil, flaxseed, and chia seed on the omega-3 fatty acid composition and sensory properties of hens' eggs. No significant difference in yolk fat content was found between treatments. The fatty acid composition of egg yolk was significantly affected by the dietary treatments. Inclusion of chia at 300 g/kg into the diet produced eggs with the highest concentration of omega-3 fatty acid. Eicosapentaenoic acid and docosahexaenoic acid were only detected in eggs from laying hens fed the diet supplemented with fish oil. Diet had a significant effect on color, flavor and overall acceptability of eggs. Types and levels of omega-3 fatty acids in feed influence the level of yolk omega-3 fatty acids in egg yolk. Inclusion of chia into the hens' diet significantly increased the concentration of yolk omega-3 fatty acid without significant change in sensory properties.
Background Increased small bowel permeability leads to bacterial translocation, associated with significant morbidity and mortality. Biomarkers are needed to evaluate these changes in vivo, stratify an individual's risk, and evaluate the efficacy of interventions. MRI is an established biomarker of small bowel inflammation. Purpose To characterize changes in the small bowel with quantitative MRI measures associated with increased permeability induced by indomethacin. Study Type Prospective single‐center, double‐blind, two‐way crossover provocation study. Subjects A provocation cohort (22 healthy volunteers) and intrasubject reproducibility cohort (8 healthy volunteers). Field Strength/Sequence 2D balanced turbo field echo sequences to measure small bowel wall thickness, T2, and motility acquired at 3T. Assessment Participants were randomized to receive indomethacin or placebo prior to assessment. After a minimum 2‐week washout, measures were repeated with the alternative allocation. MR measures (wall thickness, T2, motility) at each study visit were compared to the reference standard 2‐hour lactulose/mannitol urinary excretion ratio (LMR) test performed by a lab technician. All analyses were performed blind. Statistical Tests Normality was tested (Shapiro–Wilk's test). Paired testing (Student's t‐test or Wilcoxon) determined the significance of paired differences with indomethacin provocation. Pearson's correlation coefficient compared significant measures with indomethacin provocation to LMR. Intrasubject (intraclass correlation) and interrater variability (Bland–Altman) were assessed. Results Indomethacin provocation induced a significant increase in LMR compared to placebo (P < 0.05) and a significant increase in small bowel T2 (0.12 seconds compared to placebo 0.07 seconds, P < 0.05). Small bowel wall thickness (P = 0.17) and motility (P = 0.149) showed no significant change. T2 and LMR were positively correlated (r = 0.68, P < 0.05). T2 measurements were robust to interobserver (intraclass correlation 0.89) and intrasubject variability (Bland–Altman bias of 0.005 seconds, 95% confidence interval [CI] –0.04 to +0.05 seconds, and 0.0006 seconds, 95% CI –0.05 to +0.06 seconds). Data Conclusion MR measures of small bowel wall T2 were significantly increased following indomethacin provocation and correlated with 2‐hour LMR test results. Level of Evidence 1 Technical Efficacy Stage 2
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.