Wine quality can be significantly affected by tannin and polysaccharide composition, which can in turn be influenced by grape maturity and winemaking practices. This study explored the impact of ...three commercial wine additives, a maceration enzyme, an enotannin, and a mannoprotein, on the composition and sensory properties of red wine, in particular, in mimicking the mouthfeel associated with wines made from riper grapes. Shiraz grapes were harvested at 24 and 28 °Brix and the former vinified with commercial additives introduced either individually or in combination. Compositional analyses of finished wines included tannin and polysaccharide concentration, composition and size distribution by high-performance liquid chromatography, whereas the sensory profiles of wines were assessed by descriptive analysis. As expected, wines made from riper grapes were naturally higher in tannin and mannoprotein than wines made from grapes harvested earlier. Enzyme addition resulted in a significantly higher concentration and average molecular mass of wine tannin, which increased wine astringency. Conversely, mannoprotein addition reduced tannin concentration and astringency. Addition of enotannin did not meaningfully influence wine composition or sensory properties.
Chardonnay is one of the oldest and most widely distributed wine grape cultivars and is of commercial importance for the world’s wine-producing nations. It is an extremely flexible variety that has ...adapted to different regions with varied weather and soil characteristics. Somewhat uniquely among white wines, Chardonnay lends itself to a wide variety of production styles, which can be tailored to the target market. Techniques such as skin maceration, barrel and stainless steel fermentation, use of selected or indigenous yeasts, malolactic fermentation, and aging in barrels with or without lees are all applicable and lead to different compositional outcomes. A number of research papers have been published with a view to understanding Chardonnay composition and quality as well as the impact of different enological techniques on the final product. This review summarizes current knowledge, explaining the influence of viticultural and production techniques on aroma composition, and poses directions for further research into Chardonnay wines.
Grape seed procyanidins (PC) are flavan-3-ol oligomers and polymers known for their biological activity in the gut. Grape seed extract (GSE) have been reported to reduce intestinal injury in a rat ...model of mucositis. We sought to investigate effects of purified PC fractions differing in mean degree of polymerization (mDP) combined with 5-Fluorouracil (5-FU) chemotherapy on the viability of colon cancer cells (Caco-2).
SixPC fractions (F1-F6) were isolated from Cabernet Sauvignon seeds at two ripeness stages: pre-veraison unripe (immature) and ripe (mature), utilizing step gradient, low-pressure chromatography on a Sephadex LH-20 resin. Fractions were tested on Caco-2 cells, alone and in combination with 5-FU. Eluted fractions were characterized by phloroglucinolysis and gel permeation chromatography. Cell viability was determined by the 3-(4,5-Dimethylthiazol-2yl)-2,5-diphenyl-tetrazolium bromide) (MTT) assay.
All isolated fractions significantly reduced Caco-2 cell viability compared to the control (P<0.05), but F2 and F3 (mDP 2-6) were the most active fractions (immature F2 = 32% mDP 2.4, F3 = 35% mDP 5.8 and mature F2 = 13% mDP 3.6 and F3 = 17% mDP 5.9; percentage of viable cells remaining) on Caco-2 cells. When combined with 5-FU, immature fractions F1-F3 enhanced the cell toxicity effects of 5-FU by 27-73% (P<0.05). Mature seed PC fractions (F1-F4) significantly enhanced the toxicity of 5-FU by 60-83% against Caco-2 cells (P<0.05). Moreover, some fractions alone were more potent at decreasing viability in Caco-2 cells (P<0.05; immature fractions = 65-68% and mature fractions = 83-87%) compared to 5-FU alone (37%).
PCs of mDP 2-6 (immature F1-F3 and mature F1 and F4)not only enhanced the impact of 5-FU in killing Caco-2 cells, but also surpassed standard 5-FU chemotherapy as an anti-cancer agent.The bioactivity of PC is therefore attributed primarily to lower molecular weight PCs.
•Five Lachancea thermotolerans (LT) co-inocula were trialled in Merlot fermentations.•Compositional modulations of wines depended on both LT strain and inoculation regime.•LT wines had similar or ...lower pH/ethanol than Saccharomyces cerevisiae (SC) wines.•Ethyl lactate was up to thirty-fold higher in some LT wines than in the SC control.•Medium chain fatty acids and their ethyl esters were highest in the SC monoculture.
Wines from warm(ing) climates often contain excessive ethanol but lack acidity. The yeast Lachancea thermotolerans can ameliorate such wines due to partial conversion of sugars to lactic acid during alcoholic fermentation. This study compared the performance of five L. thermotolerans strains in two inoculation modalities (sequential and co-inoculation) to Saccharomyces cerevisiae and un-inoculated treatments in high sugar/low acidity Merlot fermentations. The pH and ethanol levels in mixed-culture dry wines were either comparable, or significantly lower than in controls (decrease of up to 0.5 units and 0.90% v/v, respectively). The analysis of volatile compounds revealed marked differences in major flavour-active yeast metabolites, including up to a thirty-fold increase in ethyl lactate in certain L. thermotolerans modalities. The wines significantly differed in acidity perception, alongside 18 other sensory attributes. Together, these results highlight the potential of some L. thermotolerans strains to produce ‘fresher’ wines with lower ethanol content and improved flavour/balance.
In a global context where trading of wines involves considerable economic value, the requirement to guarantee wine authenticity can never be underestimated. With the ever-increasing advancements in ...analytical platforms, research into spectroscopic methods is thriving as they offer a powerful tool for rapid wine authentication. In particular, spectroscopic techniques have been identified as a user-friendly and economical alternative to traditional analyses involving more complex instrumentation that may not readily be deployable in an industry setting. Chemometrics plays an indispensable role in the interpretation and modelling of spectral data and is frequently used in conjunction with spectroscopy for sample classification. Considering the variety of available techniques under the banner of spectroscopy, this review aims to provide an update on the most popular spectroscopic approaches and chemometric data analysis procedures that are applicable to wine authentication.
•SO-PLS was applied to wine sensory profiles and grape chemistry of Cabernet Sauvignon.•SO-PLS1 produced better models with higher validated explained variances than SO-PLS2.•SO-PLS can be a method ...to handle multiple X data blocks for prediction.•The proposed analysis procedure may assist in screening for important X data blocks.
The current study determined the applicability of sequential and orthogonalised-partial least squares (SO-PLS) regression to relate Cabernet Sauvignon grape chemical composition to the sensory perception of the corresponding wines. Grape samples (n = 25) were harvested at a similar maturity and vinified identically in 2013. Twelve measures using various (bio)chemical methods were made on grapes. Wines were evaluated using descriptive analysis with a trained panel (n = 10) for sensory profiling. Data was analysed globally using SO-PLS for the entire sensory profiles (SO-PLS2), as well as for single sensory attributes (SO-PLS1). SO-PLS1 models were superior in validated explained variances than SO-PLS2. SO-PLS provided a structured approach in the selection of predictor chemical data sets that best contributed to the correlation of important sensory attributes. This new approach presents great potential for application in other explorative metabolomics studies of food and beverages to address factors such as quality and regional influences.
Wine mouthfeel is considered important for wine quality by experts, while consumers understanding of mouthfeel and the role of wine body in their wine choice is unknown. One experiment determined the ...influence of intrinsic wine mouthfeel on consumers' wine liking and emotions, and the other, how consumers understand the term wine body. The first experiment used a 2 astringency level×2 body level experimental design. The samples were base wine with; nothing added (control), added xanthan gum (for increased body), added grape seed extract (GSE, for increased astringency), and with both added xanthan gum and GSE. The consumer taste trial (n=112) indicated that wine with increased body did not influence wine liking and emotions; while increased astringency decreased liking and elicited more intense negative emotions. The second experiment examined consumers' knowledge of wine body through an online survey (n=136). Consumers described wine body most frequently using words such as flavour, fullness, and strength. Wine body was therefore understood by consumers predominantly as a holistic multi-sensory perception of flavour. Wine flavour was indicated by consumers to be the most important factor driving purchase decisions followed by balance of flavours and wine body. It is crucial that wine professionals carefully communicate wine characteristics to consumers to prevent possible misunderstandings such as the meaning of wine body and as a result better meet consumer expectations. In future, the term body may benefit from a clearer definition for academic research as well as industry.
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•Changes in astringency of wine was a determinant in consumers liking and emotions.•Increases in body by addition of gum had no influence on consumers liking or emotions.•Wine body was understood by consumers as a holistic perception of flavour and intensity, not only mouthfeel.
•Authenticity of Cabernet Sauvignon wine modelled using elements and spectroscopy.•Excitation-emission matrices provided a unique molecular fingerprint for each wine.•Novel use of multivariate ...algorithm XGBoost yielded 100% correct classification.•The approach could be used in the supply chain to verify the provenance of wine.
With the increased risk of wine fraud, a rapid and simple method for wine authentication has become a necessity for the global wine industry. The use of fluorescence data from an absorbance and transmission excitation-emission matrix (A-TEEM) technique for discrimination of wines according to geographical origin was investigated in comparison to inductively coupled plasma-mass spectrometry (ICP-MS). The two approaches were applied to commercial Cabernet Sauvignon wines from vintage 2015 originating from three wine regions of Australia, along with Bordeaux, France. Extreme gradient boosting discriminant analysis (XGBDA) was examined among other multivariate algorithms for classification of wines. Models were cross-validated and performance was described in terms of sensitivity, specificity, and accuracy. XGBDA classification afforded 100% correct class assignment for all tested regions using the EEM of each sample, and overall 97.7% for ICP-MS. The novel combination of A-TEEM and XGBDA was found to have great potential for accurate authentication of wines.
Background
Grape seed extract (GSE) constitutes a rich source of procyanidins. GSE has been demonstrated to exert encouraging anti-inflammatory and anti-ulcer properties in experimental settings, ...although its effects on inflammation of the colon remain undefined.
Aim
To determine the effects of GSE in a rat model of dextran sulphate sodium (DSS) for ulcerative colitis.
Methods
Male Sprague–Dawley rats were gavaged daily (days 0–10) with GSE (400 mg/kg). Ulcerative colitis was induced by substituting DSS (2 % w/v) for drinking water from days 5–10. A sucrose breath test was performed on day 11 to determine small bowel function and intestinal tissues were collected for histological analyses. Statistical analysis was by one-way or repeated-measures ANOVA and
p
< 0.05 was considered significant.
Results
Compared to DSS-treated controls, GSE significantly decreased ileal villus height (14 %;
p
< 0.01) and mucosal thickness (13 %;
p
< 0.01) towards the values of normal controls. GSE reduced qualitative histological severity score (
p
< 0.05) in the proximal colon, although no significant effect was evident in the distal colon. However, GSE failed to prevent DSS-induced damage to the crypts of both colonic regions. Administration of GSE did not negatively impact metabolic parameters, nor did it induce any deleterious gastrointestinal side effects in healthy animals.
Conclusions
GSE decreased the severity of selected markers of DSS-induced colitis in the distal ileum and proximal colon, suggesting the potential as an adjuvant therapy for the treatment of ulcerative colitis. Future studies of GSE should investigate alternative delivery methods and treatment regimens, further seeking to identify the individual bioactive factors.
This study investigated how information, typically presented on wine back-labels or wine company websites, influences consumers' expected liking, informed liking, wine-evoked emotions and willingness ...to pay for Australian white wines. Regular white wine consumers (n=126) evaluated the same set of three commercially available white wines (mono-varietal Chardonnay, Riesling, Sauvignon Blanc) under three information levels. Session 1, blind tasting (no information provided) and Session 2, informed tasting (held at least 1week later) with both basic (sensory description of the wines) and elaborate (sensory plus high wine quality and favourable winery information) descriptions followed by liking, wine-evoked emotions (measured with the Australian Wine Evoked Emotions Lexicon (AWEEL)) and willingness to pay evaluations. Before tasting the wine in session 2, consumers also rated expected liking.
Results showed that information level had a significant effect on all investigated variables. The elaborate information level evoked higher expectations before tasting the wines, plus resulted in higher liking ratings, elicitation of more intense positive (e.g. contented, happy and warm-hearted) and less intense negative emotions (e.g. embarrassed and unfulfilled), and a substantial increase in willingness to pay after tasting the wines compared to the blind condition, with the basic condition ranging in-between. These results were consistent across the three wine samples.
Furthermore, if the liking rating after tasting the wines matched the expected liking or exceeded the expectations by 1 point on a 9-point hedonic scale, participants felt the most intense positive emotions and the least intense negative emotions. Whereas, if the expectations were not met or the actual liking exceeded the expectations by >2 points, participants felt less intense positive and more intense negative emotions. This highlights not only the importance of well written and accurate wine descriptions, but also that information can influence consumers' wine drinking experience and behaviour.
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•Three white wines were tasted under three different information conditions.•Information influenced consumers' emotions, liking and willingness-to-pay (WTP).•Elaborate information resulted in highest liking, WTP and positive emotions.•Hedonic disconfirmation strongly influenced emotion profiles.
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