Discrimination of Complex Odor Mixtures: A Study Using Wine Aroma Models

There are key unanswered questions when it comes to odor mixture discrimination. This study was designed to assess some of those questions regarding configural odor mixture discrimination in humans. We collected data to address the following two questions: 1) What odor features do humans notice when attempting to discriminate between subtly different odor mixtures? 2) Are odor mixtures easier to discriminate when an odorant is added, compared to when a component is removed? Using modern aroma chemistry techniques, an odor mixture resembling a generic white wine was constructed. This wine odor mixture was modified using a series of 3 esters which are commonly found in white wines that vary in chain length and branching. Participants performed a sequence of discrimination tasks for the addition / subtraction of modifiers to the base wine at different concentrations. Only one of the esters (ethyl-propanoate) led to a discriminable odor mixture. As concentration of the modifying odorant was increased, discrimination of odor mixtures was first reported because of changes in odor mixture familiarity and then intensity. We found similar sensitivity odor mixture discrimination regardless of addition or subtraction of modifying compounds, suggesting that perceptual stability of odor mixtures is equally dependent on both imputing missing information (pattern completion) and disregarding extraneous information.

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Discrimination of Complex Odor Mixtures: A Study Using Wine Aroma Models

Chemical Senses ◽

10.1093/chemse/bjaa079 ◽

2020 ◽

Author(s):

Curtis R Luckett ◽

Robert Pellegrino ◽

Michelle Heatherly ◽

Katherine Alfaro Martinez ◽

Melissa Dein ◽

...

Keyword(s):

White Wine ◽

Wine Aroma ◽

Missing Information ◽

White Wines ◽

Pattern Completion ◽

Perceptual Stability ◽

Odor Mixture ◽

Extraneous Information ◽

Information Pattern ◽

Odor Mixtures

Abstract There are key unanswered questions when it comes to multi-component odor discrimination. This study was designed to assess discrimination of odorant mixtures that elicit a singular percept. We collected data to address the following two questions: 1) What odor features do humans notice when attempting to discriminate between subtly different odor mixtures? 2) Are odor mixtures easier to discriminate when an odorant is added, compared to when a component is removed? Using modern aroma chemistry techniques, an odor mixture resembling a generic white wine was constructed. This wine odor mixture was modified using a series of 3 esters which are commonly found in white wines that vary in chain length and branching. Participants performed a sequence of discrimination tasks for the addition / subtraction of modifiers to the base wine at different concentrations. Only one of the esters (ethyl-propanoate) led to a discriminable odor mixture. As concentration of the modifying odorant was increased, discrimination of odor mixtures was first reported because of changes in odor mixture familiarity and then intensity. We found similar sensitivity to changes in odor mixtures regardless whether the modifying compound was added or subtracted, suggesting that perceptual stability of odor mixtures is equally dependent on both imputing missing information (pattern completion) and disregarding extraneous information.

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Effect of Pre-Fermentative Maceration and Fining Agents on Protein Stability, Macromolecular, and Phenolic Composition of Albariño White Wines: Comparative Efficiency of Chitosan, k-Carrageenan and Bentonite as Heat Stabilisers

Foods ◽

10.3390/foods10030608 ◽

2021 ◽

Vol 10 (3) ◽

pp. 608

Author(s):

Inma Arenas ◽

Miguel Ribeiro ◽

Luís Filipe-Ribeiro ◽

Rafael Vilamarim ◽

Elisa Costa ◽

...

Keyword(s):

Phenolic Compounds ◽

Protein Stability ◽

White Wine ◽

The Other ◽

White Wines ◽

Comparative Efficiency ◽

Fining Agents ◽

Protein Instability ◽

Related Proteins ◽

Protein Stabilisation

In this work, the effect of pre-fermentative skin maceration (PFSM) on the chemical composition of the macromolecular fraction, polysaccharides and proteins, phenolic compounds, chromatic characteristics, and protein stability of Albariño monovarietal white wines was studied. PFSM increased the extraction of phenolic compounds and polysaccharides and reduced the extraction of pathogenesis-related proteins (PRPs). PFSM wine showed significantly higher protein instability. Sodium and calcium bentonites were used for protein stabilisation of wines obtained with PFSM (+PFSM) and without PFSM (−PFSM), and their efficiencies compared to fungal chitosan (FCH) and k-carrageenan. k-Carrageenan reduced the content of PRPs and the protein instability in both wines, and it was more efficient than sodium and calcium bentonites. FCH was unable to heat stabilise both wines, and PRPs levels remained unaltered. On the other hand, FCH decreased the levels of wine polysaccharides by 60%. Sodium and calcium bentonite also decreased the levels of wine polysaccharides although to a lower extent (16% to 59%). k-Carrageenan did not affect the wine polysaccharide levels. Overall, k-carrageenan is suitable for white wine protein stabilisation, having a more desirable impact on the wine macromolecular fraction than the other fining agents, reducing the levels of the wine PRPs without impacting polysaccharide composition.

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Characterisation of Extracts Obtained from Unripe Grapes and Evaluation of Their Potential Protective Effects against Oxidation of Wine Colour in Comparison with Different Oenological Products

Foods ◽

10.3390/foods10071499 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1499

Author(s):

Giovanna Fia ◽

Ginevra Bucalossi ◽

Bruno Zanoni

Keyword(s):

Antioxidant Activity ◽

Red Wine ◽

Waste Product ◽

Natural Antioxidants ◽

White Wine ◽

Small Scale ◽

Protective Effects ◽

White Wines ◽

Accelerated Oxidation ◽

Wine Colour

Unripe grapes (UGs) are a waste product of vine cultivation rich in natural antioxidants. These antioxidants could be used in winemaking as alternatives to SO2. Three extracts were obtained by maceration from Viognier, Merlot and Sangiovese UGs. The composition and antioxidant activity of the UG extracts were studied in model solutions at different pH levels. The capacity of the UG extracts to protect wine colour was evaluated in accelerated oxidation tests and small-scale trials on both red and white wines during ageing in comparison with sulphur dioxide, ascorbic acid and commercial tannins. The Viognier and Merlot extracts were rich in phenolic acids while the Sangiovese extract was rich in flavonoids. The antioxidant activity of the extracts and commercial tannins was influenced by the pH. In the oxidation tests, the extracts and commercial products showed different wine colour protection capacities in function of the type of wine. During ageing, the white wine with the added Viognier UG extract showed the lowest level of colour oxidation. The colour of the red wine with the UG extract evolved similarly to wine with SO2 and commercial tannins. The obtained results indicated that natural and healthy UG extracts could be an interesting substitute for SO2 during wine ageing.

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Measuring Thiols in Single Cultivar South African Red Wines Using 4,4-Dithiodipyridine (DTDP) Derivatization and Ultraperformance Convergence Chromatography-Tandem Mass Spectrometry

Foods ◽

10.3390/foods7090138 ◽

2018 ◽

Vol 7 (9) ◽

pp. 138 ◽

Cited By ~ 4

Author(s):

Mpho Mafata ◽

Maria Stander ◽

Baptiste Thomachot ◽

Astrid Buica

Keyword(s):

South African ◽

Red Wine ◽

High Sensitivity ◽

White Wine ◽

Wine Aroma ◽

Low Concentrations ◽

Varietal Thiols ◽

Cultivar Differentiation ◽

First Time ◽

Ionization Methods

Wine varietal thiols are important contributors to wine aroma. The chemical nature of thiols makes them difficult to measure due to low concentrations, high sensitivity to oxidation, and low ionization. Methods for the measurement of thiols usually consist of multiple steps of sample preparation followed by instrumental measurement. Studies have collected large datasets of thiols in white wine but not in red wine, due to the lack of availability of suitable methods. In this study, for the first time, convergence chromatography was used to measure thiols in red wine at ultratrace levels with improved sensitivity compared to previous methods. Performance parameters (selectivity, linearity, limits of detection, precision, accuracy) were tested to demonstrate the suitability of the method for the proposed application. Red wine thiols were measured in South African Pinotage, Shiraz, and Cabernet Sauvignon wines (n = 16 each). Cultivar differentiation using the thiol profile was demonstrated.

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Comparison of a Rapid Light-Induced and Forced Test to Study the Oxidative Stability of White Wines

Molecules ◽

10.3390/molecules27010326 ◽

2022 ◽

Vol 27 (1) ◽

pp. 326

Author(s):

Emilio Celotti ◽

Georgios Lazaridis ◽

Jakob Figelj ◽

Yuri Scutaru ◽

Andrea Natolino

Keyword(s):

Oxidative Stability ◽

Oxidation Stability ◽

White Wine ◽

Sensorial Analysis ◽

White Wines ◽

Technological Interventions ◽

Prototype Instrument ◽

Fast Decision ◽

Effect Of Light

The oxidation processes of white wines can occur during storage and commercialization due to several factors, and these can negatively affect the color, aroma, and quality of the wine. Wineries should have faster and simpler methods that provide valuable information on oxidation stability of wines and allow fast decision-making procedures, able to trigger suitable technological interventions. Using a portable prototype instrument for light irradiations at different wavelengths and times was considered and evaluated on sensorial, spectrophotometric, and colorimetric parameters of white wines. The sensorial analysis revealed that white and light blue were the most significant, after only 1 h of irradiation. The experimental results showed that hydrogen peroxide could enhance the effect of light treatment, allowing a contemporary evaluation of the oxidation stability of wine against light and chemical stresses. As expected, a good correlation (R2 > 0.89) between optical density at 420 nm and b* parameter was highlighted. The synergic effect of light and H2O2 was also studied on the hydrolyzable and condensed tannins’ additions to white wine. The proposed methodology could be used to evaluate the oxidative stability of white wines, but also to evaluate the effect of some oenological adjuvants on wine stability.

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Determination of Color in White Wine and White Grape Juice Using the White Wine Colorimeter

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/60.3.739 ◽

1977 ◽

Vol 60 (3) ◽

pp. 739-740

Author(s):

Herb L Wildenradt ◽

Paul A Stafford

Keyword(s):

Grape Juice ◽

White Wine ◽

Color Measurement ◽

White Wines ◽

Reproducible Method ◽

Grape Juices

Abstract Further experience with the white wine colorimeter has demonstrated that this instrument provides a simple and reproducible method of color measurement for both finished and unfinished white wines and white grape juices. In view of the proven accuracy and utility of the white wine colorimeter, the method specifying this instrument, 11.B01–11.B02, has been adopted as official final action.

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Regeneration of Magnetic Nanoparticles Used in the Removal of Pathogenesis-Related Proteins from White Wines

Foods ◽

10.3390/foods9010001 ◽

2019 ◽

Vol 9 (1) ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

Agnieszka Mierczynska-Vasilev ◽

Geridi Qi ◽

Paul Smith ◽

Keren Bindon ◽

Krasimir Vasilev

Keyword(s):

Magnetic Nanoparticles ◽

Acrylic Acid ◽

Water Solution ◽

White Wine ◽

Wine Industry ◽

White Wines ◽

Pathogenesis Related Proteins ◽

Removal Capacity ◽

Pathogenesis Related ◽

Related Proteins

Protein haze remains a serious problem for the wine industry and requires costly bentonite treatment, leading to significant wine volume loss. Recently developed magnetic separation technology that allows a fast and efficient separation of haze proteins from wine shows promise for the development of an alternative method for white wine fining. The key purpose of this study was to understand the potential of the nanoparticles to be reused in multiple fining and regeneration cycles. Bare and acrylic-acid-based plasma polymer coated magnetic nanoparticles were cleaned with water, 10% SDS/water and acetone/water solution after each adsorption cycle to investigate their restored efficiency in removing pathogenesis-related proteins from three unfined white wines. The concentrations of metals, acids and phenolics were monitored to determine changes in the concentration of these essential wine constituents. The regeneration study verified that the acrylic acid plasma-coated magnetic nanoparticles, which underwent ten successive adsorption-desorption processes, still retained close to the original removal capacity for haze proteins from wines when 10% SDS solution and water were used for surface regeneration. In addition, the concentrations of organic acids and wine phenolic content remained almost unchanged, which are important indicators for the retention of the original wine composition.

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Comparison of an Offline SPE–GC–MS and Online HS–SPME–GC–MS Method for the Analysis of Volatile Terpenoids in Wine

Molecules ◽

10.3390/molecules25030657 ◽

2020 ◽

Vol 25 (3) ◽

pp. 657 ◽

Cited By ~ 1

Author(s):

Cody Williams ◽

Astrid Buica

Keyword(s):

Sample Preparation ◽

Solid Phase ◽

White Wine ◽

Gas Chromatography Mass Spectrometry ◽

Wine Quality ◽

White Wines ◽

Preparation Methods ◽

Odor Thresholds ◽

Spe Method ◽

Sample Preparation Methods

The aroma profile is an important marker for wine quality. Various classes of compounds are responsible for the aroma of wine, and one such class is terpenoids. In the context of this work, a validated gas chromatography–mass spectrometry (GC–MS) method for the quantitation of terpenoids in red and white wine using headspace solid-phase microextraction (HS–SPME) and solid-phase extraction (SPE) was established. Calibrations were performed in the respective base wine using both sample preparation methods. The linearity, precision and accuracy evaluated for the respective matrices were excellent for both sample preparations. However, the HS–SPME approach was more sensitive and more accurate. For both sample preparations, the quantification limits were lower than the odor thresholds in wine. The terpenoid concentrations (µg/L) were evaluated for 13 white wines using both sample preparation methods. Importantly, the online HS–SPME approach was more sensitive than the offline SPE method. The major terpenoids identified in the white wines evaluated were linalool (0.2–63 µg/L), geraniol (nd–66 µg/L) and α-terpineol (nd–85 µg/L).

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Relationships between the varietal volatile composition of the musts and white wine aroma quality. A four year feasibility study

LWT ◽

10.1016/j.lwt.2010.06.007 ◽

2010 ◽

Vol 43 (10) ◽

pp. 1508-1516 ◽

Cited By ~ 13

Author(s):

Sílvia M. Rocha ◽

Paula Coutinho ◽

Elisabete Coelho ◽

António S. Barros ◽

Ivonne Delgadillo ◽

...

Keyword(s):

Feasibility Study ◽

White Wine ◽

Wine Aroma ◽

Volatile Composition

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Odor mixture perception: can molecular complexity be a factor determining elemental or configural perception?

10.1101/2020.05.27.120154 ◽

2020 ◽

Author(s):

Masayuki Hamakawa ◽

Hiroya Ishikawa ◽

Yumika Kikuchi ◽

Kaori Tamura ◽

Tsuyoshi Okamoto

Keyword(s):

Principal Component Analysis ◽

Structural Complexity ◽

Principal Component ◽

Low Complexity ◽

Olfactory Perception ◽

High Complexity ◽

Odor Mixture ◽

Individual Odor ◽

Odor Mixtures ◽

Molecular Complexity

AbstractOdor mixtures can evoke smells that differ from those of their individual odor components. Research has revealed the existence of two perceptual modes, in which a mixture can be perceived as either the original smells of its individual components (elemental) or as a novel smell (configural). However, the factors underlying the perceptual transformation that occurs when smelling a mixture versus its original components remain unclear. Therefore, the present study aimed to identify the properties of odorants that affect olfactory perception of odor mixtures, focusing on the structural complexity of an odorant. We conducted psychophysical experiments in which different groups of participants were instructed to provide olfactory perceptual descriptions of low-, medium-, and high-complexity odor mixtures or components, respectively. To investigate the perceptual modes induced by the mixtures, we compared the participants’ evaluations between mixtures and components via two types of analyses. First, we compared each olfactory description following quantification via principal component analysis. We then compared data based on seven major olfactory perceptual groups. We observed that odor mixtures composed of low-complexity odorants were perceived as relatively novel smells with regard to both minor (olfactory descriptions) and major (perceptual community) odor qualities than medium- and high-complexity mixtures. Such information may further our understanding of the olfactory perceptual modes of odor mixtures.

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