Anita Oberholster Overview of the Red and White Wine Mouthfeel Wheels

Introduction Tastes and tactile sensations Matrix influence on bitterness + astringency Phenol composition Sensory properties of phenolics Development of red wine mouthfeel wheel Use of RMFW Development of white wine mouthfeel wheel

Astringency Perception Astringency described as “roughing”, “drying” and “puckering” Tactile sensation Mechanism of astringency – Phenols bind with saliva proteins and precipitate – Stripping the mouth of lubrication “drying” – Texture effect of astringency could be due to precipitated complexes or those in solution Astringency is dynamic process – Changes during ingestion and expectoration Oberholster (2008)

Influences on Astringency + Bitterness Ethanol % – Decrease astringency perception – Increase bitterness perception Sugar content – Decrease bitterness – No influence on astringency, but more difficult to perceive Gawel (1998) Austr. J. Grape Wine Res. 4, p

Influences on Astringency + Bitterness Other wine compounds such as organic acid have astringent sub-qualities themselves – Also contribute by lowering pH,  phenol- protein interactions Polysaccharides and proteins – Binds with tannins, reduce astringency Gawel (1998) Austr. J. Grape Wine Res. 4, p McRae and Kennedy (2011) Molecules 16, p

Variation within Tasters Effect of variation in salivary flow rate on time-intensity scaling of bitterness and astringency – Low-flow; perceive max intensity later, more intense, persistence longer Oberholster (2008)

Astringency as a taste Average time-intensity curves for astringency in wine upon three successive ingestions: left 20s between ingestions; right 40s between ingestions. Sample uptake and swallowing are indicated by a star and arrow, respectively Guinard et. al., 1986

Phenolics: Main Contributors to Astringency and Bitterness Main phenols (flavonoids) in red wine – Anthocyanins responsible for red color – Flavan-3-ols (ex. catechin, epicatechin) Oligomers and polymers of flavan-3-ols, so called proanthocyanidins (PA) or condensed tannins Fig 1 Anthocyanin

Figure 1: Proanthocyanidins Extension units Terminal unit

Background – phenols in wine Extraction during wine making – Anthocyanins from skins Early during fermentation (3-5 days) – Seed PA (mDP ~ 10), higher % galloylation – Skin PA (mDP ~ 30), also contain (epi)gallocatechin units Increase extraction with temp, % EtOH

Sensory Properties of Flavanols Gawel et al. (1998) Austr. J. Grape Wine Res.(6) 74 Monomers more bitter than astringent Ratio of astringency to bitterness  with  mDP

Polymeric Phenols and Astringency Sensory properties of proanthocyanidins (PA) – Main contributors to bitterness and astringency – Ratio of astringency to bitterness increase with mDP During wine maturation and ageing – Anthocyanins and PA polymerise with each other by different mechanisms – Influenced by grape composition, presence of wood (hydrolyzable) tannins Gawel et al. (1998) Austr. J. Grape Wine Res.(6) 74; Vidal et al. (2003) J. Sci. Food Agric. (83) 564

Wine pigments Direct condensation Mateus et al., (2003) J. Agric. Food Chem. 51: ; Reynolds (2010) Managing wine quality. Flavanyl-vinyl-pyranoanthocyanin

Sensory properties of polymerization products How does polymerization reactions/products formed during wine aging influence Mouthfeel? Characterization of polymeric pigments – Comparing the polymeric pigment profile of 6 month old and 5 year old Syrah wine from the same vineyard  conc. of polymeric pigments, methylmethine and vinyl-linked pigments mDP of wine 4  10 – Development of the Mouthfeel wheel Oberholster (2008)

Developing the Mouthfeel wheel Panel of 14 tasters tasted 72 wines over 6 week period to derive a vocabulary – 6 months to 33 year old red wines (mean 4 yrs) – Mostly Australian Shiraz, Cab. Sauv. Pinot noir, Grenach Another 75 red wines tasted to derive Mouthfeel terms not astringent-like – Influence Mouthfeel Investigate standards – Taste standards for astringency not practical Gawel, Oberholster, Francis (2000) Austr. J. Grape Wine Res.(6)

Standards for Mouthfeel Taste standards – Commercial tannins and other Complex profiles Tiring, influence subsequent perceptions Carry-over effects – Touch standards Cutaneous sensations similar to those experienced in the mouth – Terms not represented by physical standards – well defined Gawel, Oberholster, Francis (2000) Austr. J. Grape Wine Res.(6)

Mouthfeel wheel Gawel, Oberholster, Francis (2000) Austr. J. Grape Wine Res.(6)

Mouthfeel Wheel Astringency Gawel, Oberholster, Francis (2000) Austr. J. Grape Wine Res.(6)

Touch Standards Representing Tactile Sensations DescriptorTouch standard TalcJohnson baby powder SatinSatin cloth PlasterGypsum powder ChamoisMoistened chamois SilkHigh grade silk cloth VelvetVelvet felt in direction of the nap SuedeMedium suede leather FurryShort velour cloth Fine emery paper1000 grade emery paper CorduroyMedium cord cloth Abrasive600 grade sandpaper HessianCarpet backing

Touch Standards Representing Tactile Sensations Satin Silk SuedeVelvet Sandpaper 1000 grade Fur (Furry) Corduroy Sandpaper 600 grade (Abrasive) Soft Suede (Chamois) Burlap (Hessian)

Supplementary Definitions for Astringency Terms

Non-astringent Mouthfeel Terms Gawel, Oberholster, Francis (2000) Austr. J. Grape Wine Res.(6)

Using the Mouthfeel Wheel (MFW) Vidal (2003, 2004) fractionated tannins from grape material – evaluate with MFW – Larger tannin more astringent and drying than smaller tannin – Seed tannin more astringent (coarse, drying) than skin tannin of equivalent size – Indicate  ‘Coarseness’ and ‘dryness’ of astringency increase with galloylation – Methylmethine-bridged flavanols more bitter than similar tannins Vidal et al. (2003) J. Sci. Food Agric. (83) 564 Vidal et al. (2004) Food Qual. Pref. 15,

Using the Mouthfeel Wheel (MFW) Anthocyanins have no taste or tactile effect (Singleton and Trousdale, 1992) Anthocyanins  perceived astringency and “fullness” of model wine (Vidal et al., 2004b) Anthocyanins – more pure – no significant contribution to Mouthfeel (Vidal et al., 2004a) How do you explain differences between white wine and red wine? Singleton and Trousdale (1992) AJEV 43, Vidal et al. (2004a) Food Qual. Pref. 15, Vidat et al. (2004b) Food Chem. 85,

Using the Mouthfeel Wheel (MFW) How do you explain changes in Mouthfeel observed during aging? – Could polymerization reactions explain changes in Mouthfeel observed? – Increase mDP proanthocyanidins  astringency – Formation of polymeric pigments? Oberholster et al, (2009) Austr. J. Grape Wine Res. (15) Singleton and Trousdale (1992) AJEV 43, Vidal et al. (2004a) Food Qual. Pref. 15, Vidat et al. (2004b) Food Chem. 85,

Mouthfeel of different white wine treatments Oberholster et al, (2009) Austr. J. Grape Wine Res. (15) White free run juice White free run juice + anth Red wineWhite free run juice + white skins and seeds + anth White free run juice + white skins + seeds White free run juice + red skins and seeds WWAWSWSAWRSRS

Mouthfeel Wheel Oberholster et al, (2009) Austr. J. Grape Wine Res. (15) Medium grain (Bentonite) Coarse grain (Celite S45 filter aid) Fine grain (Talcum powder)

Mouthfeel of different white wine treatments Oberholster, et al.,(2009) Austr. J. Grape Wine Res. (15) W: white free run juice WA: white free run juice + anth WS: white free run juice + white skins and seeds WSA: white free run juice + white skins and seeds + anth WRS: white free run juice + red skins and seeds RS: red wine

Conclusion – RW-MFW Using the MFW – small differences in phenol content could be related to Mouthfeel differences – Anth increases astringency related terms, mainly fine grain sub-attributes But MFW is difficult to use – needs extensive training Doubt wine consumers will be able to use this wheel to communicate in meaningful way

White Wine Mouthfeel Wheel White wine elicit wide range of taste and mouthfeel sensations Pickering et al. (2008) evaluated 136 wines – Table, sparkling, dessert and fortified white wines – Using hierarchical wheel structure – Developed definitions and reference standards Tool to aid training and communication between wine professionals – Help define influence of viticultural and enological variable on white wine quality

White Wine Mouthfeel Wheel

Some major difference between the white and red mouthfeel wheel – Contains taste parameters – Avoided terms related to flavor even though observed retro-nasally – Inclusion of “time dimension” in the wheel – Descriptors are ordered clockwise starting at 12’ noon in approx order of perception and intensity perceived RMFW has no intensity levels build in Pickering and DeMiglio (2008) J. Wine Res. 19 (1) p

White Wine Mouthfeel Wheel EtOH % – Elicit tactile sensations Heat/irritation Astringent-like drying  EtOH enhance lubricity of oral cavity – reducing the perception of roughness Glycerol – Could contribute to perceived viscosity, reducing roughness, decreasing astringency Polysaccharides can also potentially contribute in similar way as glycerol Gawel et al. (2007) Austr. J. Grape Wine Res. 13, p Pickering and DeMiglio (2008) J. Wine Res. 19 (1) p

White Wine Mouthfeel Wheel Discrete sensations ⁻Used RMFW as reference so some similar terms ⁻Diffr groupings of sensations

White Wine Mouthfeel Wheel Discrete sensations ⁻Surface smoothness terms have levels associated ⁻Satin, silk and chamois are different levels of smoothness ⁻Particulate terms are grouped under surface smoothness

White Wine Mouthfeel Wheel

Integrated sensations ⁻These product are associated with sparkling wines ⁻Seems body and weight related

White Wine Mouthfeel Wheel Integrated sensations ⁻These product are associated with sparkling wines ⁻Seems body and weight related

Integrated sensations

White Wine Mouthfeel Wheel Usefulness of WMFW is still unknown Due to different WMFW and RMFW concepts – Using both wheels will be confusing – Too many complex or integrated terms which is not well defined – Both wheels can be adapted for personal use – Simplified and clarified further

Thank you Funding (GWRDC) Mouthfeel panel Elizabeth Waters Graham Jones Patrick Iland Leigh Francis Richard Gawel Karen Block Linda Bisson Lucy Joseph Kay Bogart

Touch Standards Representing Tactile Sensations Satin Silk SuedeVelvet Sandpaper 1000 grade Fur (Furry) Soft Suede (Chamois) Sandpaper 600 grade (Abrasive) Burlap (Hessian) Corduroy

Mouthfeel Standards and Definitions Satin Silk SuedeVelvet Sandpaper 1000 grade Fur (Furry) Soft Suede (Chamois) Sandpaper(Abrasive) Burlap (Hessian) Corduroy