[PDF] Perception Of Vegetative And Fruity Aromas In Red Wine And Evaluation Of A Descriptive Analysis Panel Using Across Product Vs Across Attribute Serving eBook

Author : John Hudelson
Publisher : Board and Bench Publishing
Page : 100 pages
File Size : 22,95 MB
Release : 2010-11-01
Category : Cooking
ISBN : 1891267116

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A precise and comprehensive description of the problems encountered at times by all winemakers and wine judges, Wine Faults covers the differences between flaws and faults, how flavors develop, how taste works, and how it differs from smell in the evaluation of wine. From there it tackles the increasing problems resulting from high alcohol wines as well as volatile acidity found in high pH wines common in some warm grape-growing regions. It also deals with the vegetal qualities of cool viticultural regions usually caused by methoxypyrazines and the occasional lady beetle. Every microbial infection found in today's wineries is fully described and arrayed in full color slides. Dense as the material may seem, the book is written in a manner that the layperson, or even the quality control professional who forgot that he ever took organic chemistry, can understand.

Author : Harry T. Lawless
Publisher : Springer Science & Business Media
Page : 603 pages
File Size : 12,12 MB
Release : 2010-09-27
Category : Technology & Engineering
ISBN : 1441964886

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The ?eld of sensory science has grown exponentially since the publication of the p- vious version of this work. Fifteen years ago the journal Food Quality and Preference was fairly new. Now it holds an eminent position as a venue for research on sensory test methods (among many other topics). Hundreds of articles relevant to sensory testing have appeared in that and in other journals such as the Journal of Sensory Studies. Knowledge of the intricate cellular processes in chemoreception, as well as their genetic basis, has undergone nothing less than a revolution, culminating in the award of the Nobel Prize to Buck and Axel in 2004 for their discovery of the olfactory receptor gene super family. Advances in statistical methodology have accelerated as well. Sensometrics meetings are now vigorous and well-attended annual events. Ideas like Thurstonian modeling were not widely embraced 15 years ago, but now seem to be part of the everyday thought process of many sensory scientists. And yet, some things stay the same. Sensory testing will always involve human participants. Humans are tough measuring instruments to work with. They come with varying degrees of acumen, training, experiences, differing genetic equipment, sensory capabilities, and of course, different preferences. Human foibles and their associated error variance will continue to place a limitation on sensory tests and actionable results. Reducing, controlling, partitioning, and explaining error variance are all at the heart of good test methods and practices.

Author : Andrew Poveromo
Publisher :
Page : pages
File Size : 13,25 MB
Release : 2019
Category :
ISBN :

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Wine flavor is incredibly complex, in part, due to the complex chemical composition. The matrix consists of major components like water and ethanol, as well as minor and trace compounds such as glycerol, phenolics, proteins, minerals, organic acids, and volatiles. All of these components contribute to the overall flavor of the wine, whether directly or indirectly through interactions with other components. Therefore, it is very important to understand the effects and interactions of matrix factors like ethanol, glycerol, phenolics, and proteins, to better understand wine flavor and aroma and to allow winemakers to have greater control over the sensory properties of their finished product through winemaking. Currently, much of the literature on wine flavor explores the sensory properties of red, Vitis vinifera wines. This is interesting as white wine is not only important to the worlds wine industry, but it also behaves differently than red wine. Conclusions made about the flavor of red wine do not necessarily hold true in white wines. Much of the research done also involves Vitis vinifera species and not hybrid species. Hybrid grapes are very important to wine producing regions in the northern United States and Canada as they tend to survive better in cooler and more humid climates and in areas where diseases are more prevalent. Hybrid grapes differ in their composition from Vitis vinifera grapes, in that they have a lower tannin concentration but a greater concentration of proteins and glycosylated anthocyanins. This difference in composition potentially leads to a difference in sensory properties. Therefore, it is important to understand how wine matrix components affect the flavor of hybrid wines.There is also a lack of work using temporal evaluation methods to characterize wines. The sensory attributes of wine change over time and throughout the course of consumption. Traditional static sensory evaluation methods, such as descriptive analysis, may not capture sensory properties that change over time. It is necessary to address this lack of temporal research in white, hybrid wines to better understand the effect that the matrix components have on the temporal perception of sensory attributes.In this study, we set out to characterize model white, hybrid wine samples using descriptive analysis (DA) and temporal check-all-that-apply (TCATA). The chemical data was also used in an attempt to predict the sensory attributes. In the model wine samples, pH was kept consistent while levels of ethanol, glycerol, phenolics, and protein were varied. An aroma fraction, modeled after a white, hybrid Traminette wine was added at a consistent concentration to each of the samples to evaluate the effects that each of the experimental wine components had on the static and dynamic perception of the sensory attributes along with the effects that each component had on the partitioning of volatile aroma compounds into the headspace of the samples. A descriptive analysis panel, on 17 sensory attributes, found significant differences (p

Author : Peter Andrew Buffon
Publisher :
Page : pages
File Size : 26,20 MB
Release : 2014
Category :
ISBN : 9781321014136

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In the world of modern vinification, cross flow filtration and pumping are widely used. In the absence of systematic studies examining the effects of these unit operations on the resulting wine, winemakers are sometimes reluctant to use them to process their wines. Because cross flow filtration can not be accomplished without pumping, both of these unit operations were studied . Cross flow filtration is an increasingly common post-fermentation process in the wine industry. Because of the nature of the membranes used in this process, our hypothesis was that cross flow filtration would not have a significant impact on the sensory or chemical properties of either white or red wines. To investigate this, a California white wine blend and a California red wine blend were filtered in three 570 L lots using a Bucher Vaslin cross flow unit with a nominal 0.22 micron polyethersulfone membrane. The unfiltered control was sent directly to the bottling line without filtration. Panelists evaluated the wines nine times during an eight-month descriptive analysis panel with replicated tasting at each time point. UV-VIS spectrophotometry and the Adams-Harbertson assay were used to determine color and phenolic content of the filtered and unfiltered wines respectively. The effect of filtration was found to be significant for one sensory attribute out of 16 total measured in the white wine. Similar analysis for the red wines indicated that six sensory attributes were significantly different out of 16 total in the red wine. Unfiltered red wines were found to be higher in earthy, grassy, oak, and smoke aromas compared to filtered wines and lower in mixed berry and stone fruit aromas compared to the filtered wines, but only after two months in bottle. Cross flow filtration was found to have a stabilizing effect on the sensory profile of both wines. For both red and white wines, there were significant changes in color and phenolic profile with filtration, but it is not clear, especially for red wines, that the changes in phenolic compound concentration were large enough to be detected sensorially.The transfer of must, juice, and wine is a necessary process in vinification at various points from grape receiving through bottling. Pumps are among the most important pieces of equipment used to move wine from one place to another in commercial wineries. However, there has been a general lack of systematic data generated to assess the effect of pumping on the chemical and sensory properties of wine. These effects, if found, could be due to oxygen pickup during pumping, or some other mechanism of converting mechanical energy to changes in wine composition. To investigate this, a white wine blend and a red wine blend were pumped through a closed loop system at two different run times. Three different pumps were used in the experiment, a centrifugal pump, a flexible impeller pump, and a progressive cavity pump. This resulted in six treatments each for the white and red wines. The entire experiment was carried out in duplicate. A full sensory descriptive analysis panel was conducted on the wines using a ballot-trained panel. UV-VIS spectrophotometery and the Adams-Harbertson assay were used to determine color and phenolic content of the pumped and unpumped wines, respectively. Panelists were not able to differentiate pumped wines from the control, and additionally progressive cavity, flexible impeller, or centrifugal pumped wines from each other. Although statistically significant color differences were found between red wine treatments, these differences were less than 2% and no statistically significant phenolic differences were observed. Oxygen pickup was observed in the progressive cavity pump treatment, but relatively little was observed in the flexible impeller or centrifugal pump treatments. In summary, pumping caused little to no chemical or sensory changes in the experimental wines.

Author : Palmina De Miglio
Publisher :
Page : pages
File Size : 23,61 MB
Release : 2004
Category :
ISBN :

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The first objective of this study was to identify appropriate sensory descriptors to assess the astringent sub-qualities of red wine. The influence of pH and ethanol on the sensation of astringency in red wine was evaluated, using a de-alcoholized red wine. A portion of the wine was adjusted to the pH values of 3.2, 3.4, 3.6 and 3.8, and another portion was adjusted to ethanol concentrations of 0%, 6%, 12%, and 15%. In addition, the pH 3.4 and 3.6 treatments were adjusted to an ethanol concentration of 12% and 15% all wines were then assessed sensorially and seventeen terms were identified, through panel discussion, to describe the mouth-feel and taste qualities: velvet, aggressive, silk/satin, dry, fleshy, unripe, pucker viscosity, abrasive, heat, chewy, acidity, grippy/adhesive, bitter, balance, overall astringency, and mouth-coat. Descriptive analysis profiling techniques were used to train the panel and measure the intensity of these attributes. It was found that decreasing pH values (averaged across all ethanol concentrations) showed an increase in the overall astringency of the wine. The combined treatments of ethanol and pH, real wine parameters (pH 3.4 and 3.6; 12% and 15% ethanol) did not have an effect on the perception of the astringent sub-qualities of the wine. A time intensity study was also included using the pH and ethanol adjusted wines, which showed that as the ethanol level of the wines increased so did the time to maximum intensity. The second objective was to identify appropriate sensory descriptors to evaluate the influence of grape maturity and maceration technique (grape skin contact) on the astringency sub-qualities of red vinifera wines from Niagara. The grapes were harvested across two dates, representing an early harvest and a late harvest. A portion of the Cabernet Sauvignon grapes wine was divided into three maceration treatments of oneweek maceration, standard two-week maceration, three-week maceration, and MCM. Another portion of both the early and late harvest Cabernet Sauvignon grapes were chaptalized to yield a final ethanol concentration of 14.5%. The wines were assessed sensorially and thirteen terms were identified, through panel discussion, to describe the mouth-feel and taste qualities: carbon dioxide, pucker, acidity, silk/chamois, dusty/chalky/powdery, sandpaper, numbing, grippy/adhesive, dry, mouthcoat, bitter, balance and, overall astringency. Descriptive analysis techniques were used to train the panel and measure the intensity of these attributes. The data revealed few significant differences in the mouth-feel of the wines with respect to maturity; which included differences in overall astringency and balance. There were varietal differences between Cabernet Sauvignon, Cabernet Franc, and Pinot Noir and differences for Cabernet Sauvignon wines due to the length and manner of maceration and as a result of chaptalization. Statistical analysis revealed a more complex mouth-feel for the Pinot Noir wines; and an increase in the intensity of the astringent sub-qualities as a result of the addition of sugar to the wines. These findings have implications for how processing decisions, such as optimum grape maturity and vinification methods may affect red wine quality.

Author : Dwayne Michael Bershaw
Publisher :
Page : pages
File Size : 47,28 MB
Release : 2010
Category :
ISBN : 9781124222783

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Projective mapping is gaining popularity as a technique to quickly perform sensory analysis on foods and beverages. Projective mapping eliminates the long training and product repetition of a conventional descriptive panel, and thus is an excellent sensory tool for panelists unable to participate in a conventional panel due to time or logistical constraints. Recently interest has also increased in the use and meaning of the term minerality as a wine descriptor. This study used a group of white wines, many of which were described by professional critics as having minerality, to compare a projective mapping analysis performed by wine industry professionals to a standard sensory descriptive analysis. The sensory data obtained from the panels are similar, but a specific difference occurred with respect to minerality and acid taste that may relate to how the panels were performed. The projective mapping panel found minerality to be positively correlated with acid taste and citrus, fresh, wet stone, and chemical aromas, and negatively correlated to butter, butterscotch, vanilla, and oak aromas. The descriptive analysis panel found mineral aroma (mineral taste was not chosen as an attribute through consensus) to be positively correlated with reduced, chalky, and grassy aromas and bitter taste, and negatively correlated with barrel, caramel, honey, juicy fruit, musty and cat pee aromas. Panel results were also compared to standard chemical analyses of the wines. Mineral description in the expert panel was found to be associated with malic acid and titratable acidity (TA) and tartaric acid levels in the wines. These data indicate that minerality may be related either to a group of aromatic compounds perceptible by smell, or to wine acids (specifically malic acid) perceptible by taste, or a composite of both aroma and taste compounds.