terclim by ICS banner
IVES 9 IVES Conference Series 9 OENOLOGICAL STRATEGIES FOR THE REMOVAL OF PINKING IN WHITE WINE

OENOLOGICAL STRATEGIES FOR THE REMOVAL OF PINKING IN WHITE WINE

Abstract

The pinking of in white wine is the turning of color from yellow to salmon hue. White wines obtained from certain grape varieties (e.g. Chardonnay, Sauvignon blanc, Riesling, Trebbiano di Lugana) showed to be susceptible to pinking [1] that has been evaluated by an assay providing the addition of hydrogen peroxide. Even if its appearance does not seem to affect the sensory properties [2], strategies are necessary for its removal. Nowadays, the treatment with polyvinylpolipirroline (PVPP) was reported to significantly decrease the pink color [3]. To assess other additives and co-adjuvants suitable for pinking removal, this study aimed to identify the wine treatment(s) most effective for achieving this purpose.

A white wine showing the pinking fault was added with several additives and co-adjuvants, including active charcoals (bleaching and deodorizing), bentonites, gelatine, PVPP, PVI/PVP, chitosan, potassium caseinate, kaolin, zeolite, silica, calcium phytate, oenological tannins (oak and grape skin), glutathione, ascorbic acid (without/with sulfur dioxide) yeast derivatives for a total of 23 removal assays. The wines were stored up to 26 days and their susceptibility to pinking was carried out at 4 sampling points (day 1, 5, 15 and 26) through the hydrogen peroxide test. The wine was considered susceptible to pinking (SP) when an increase of 5 mAU was observed at 500 nm [4]. Moreover, the pink color index at 500 nm (wit-hout hydrogen peroxide) was determined.

No change in the pink color index was found with the exception of potassium caseinate. Some of the tested additives and co-adjuvants were not effective in limiting SP, including active charcoals, bentonite, gelatine, kaolin, zeolite, silica, grape skin tannin, glutathione and ascorbic acid. For some of them, an increased SP was evidenced (e.g. kaolin, zeolite, grape skin tannin). The treatment with PVI/PVP strongly decreased the pinking susceptibility already after 1 day. In this condition, the wine was not SP anymore at day 15. For this sampling time, three of the yeast derivatives tested, chitosan, PVPP, potassium caseinate and oak tannins limited the pinking susceptibility. The addition of PVPP, the mainly used co-adjuvant, did not result the most relevant one to solve such significant color change. Further study will investigate the selected additives and co-adjuvants in other pink wines as well as in combination in order to identify the most promising treatment for the pinking removal.

 

1. Andrea-Silva, J., Cosme, F., Ribeiro, L. F., Moreira, A. S. P., Malheiro, A. C., Coimbra, M. A., Domingues, M. R. M., & Nunes, F. M. (2014). Origin of the pinking phenomenon of white wines. Journal of Agriculture and Food Chemistry, 62, 5651–5659. https://doi.org/10.1021/jf500825h
2. Nel, A.P., du Toit, W.J., & van Jaarsveld, F.P. (2021). Sensory evaluation of pinked Sauvignon blanc wines. South African Journal of Enology and Viticulture, 42, 175-183. http://dx.doi.org/10.21548/42-2-4316
3. Simpson R., Miller G., Orr L. (1982). Oxidative pinking of white wines: recent observations. Food technology in Australia, 34, 
44- 47.
4. Simpson R.F. (1977). Oxidative pinking in white wines. Vitis, 16, 286-286.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Daniela Fracassetti1,*, Francesca Domenighini¹, Alessio Altomare¹, Maria Manara², Antonio Tirelli¹

1. Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Via G. Celoria 2, 20133 Milan, Italy
2. Research and Developments, Dal Cin S.p.a., Via I Maggio 67, 20863 Concorezzo, Italy 

Contact the author*

Keywords

Wine treatments, PVI/PVP, Chitosan, Yeast derivatives

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

Overhead spray water treatment as a mitigation strategy for reducing vine stress and preserving grape quality during heatwaves

Changes in climate have been influencing the quality of wine grapes worldwide. The impact of extreme climate events over short periods is increasingly recognized as a serious risk to grape quality and yield quantity. In this study the mitigation effects of a pulsed water spray on vine canopy during heatwave events has been evaluated for maintaining vine condition during the growing season and grape quality. Vines of three varieties (Malbec, Bonarda, and Syrah) under drip irrigation in the UNCuyo experimental vineyard were treated with an overhead pulsed water spray.

USING CHECK-ALL-THAT-APPLY (CATA) TO CATEGORIZE WINES: A DECISION-MAKING TOOL FOR WINE SELECTION

Bordeaux is the largest appellation vineyard in France. This contrasting vineyard with varied terroirs offers all styles of wine, resulting from the blending of several grape varieties. If these different profiles make the renown of Bordeaux wines, it can appear as a constraint when the aim is to study Bordeaux wines in their diversity. The selection of a representative sample can be performed by a sensory analysis carried out by trained panelists or by wine professionals, which can take several forms: consensus among experts, conventional descriptive analysis, typicality or quality evaluation. However, because of time, economic, and logistical constraints, these methods have limited applications. As an alternative to classical descriptive analysis, more intuitive methods that do not require training have been proposed recently to describe wines using an expert panel such as Napping, Free Choice or Flash Profiling, CATA or RATA.

WINE SWIRLING: A FIRST STEP TOWARDS THE UNLOCKING OF THE WINE’STASTER GESTURE

Right after the pouring of wine in a glass, a myriad of volatile organic compounds, including ethanol, overwhelm the glass headspace, thus causing the so-called wine’s bouquet [1]. Otherwise, it is worth noting that during wine tasting, most people automatically swirl their glass to enhance the release of aromas in the glass headspace [1]. About a decade ago, Swiss researchers revealed the complex fluid mechanics underlying wine swirling [2]. However, despite mechanically repeated throughout wine tasting, the consequences of glass swirling on the chemical space found in the headspace of wine glasses are still barely known.

BORDEAUX RED WINES WITHOUT ADDED SULFITES SPECIFICITIES: COMPOSITIONAL AND SENSORY APPROACHES TOWARDS HIGHLIGHTING AND EXPLAI-NING THEIR SPECIFIC FRUITINESS AND COOLNESS

With the development of naturality expectations, wines produced without any addition of sulfur dioxide (SO₂) become very popular for consumers and such wines are increasingly present on the market. Recent studies also showed that Bordeaux red wines without added SO₂ could be differentiated from a sensory point of view from similar wines produced with SO₂¹. Thus, the aim of the current study was to characterize from a sensory point of view, specific aromas of wines without added SO₂ and to identify compounds involved.

Searching for the sweet spot: a focus on wine dealcoholization

It is well known that the vinification of grapes at full maturation can produce rich, full-bodied wines,
with intense and complex flavour profiles. However, the juice obtained from such grapes may have very
high sugar concentration, resulting in wines with an excessive concentration of ethanol. In addition, the decoupling between technological maturity and phenolic/aromatic one due to global warming, exacerbates this problem in some wine-growing regions. In parallel with the increase of the mean alcohol content of wines on the market, also the demand for reduced alcohol beverages has increased in recent years, mainly as a result of health and social concerns about the risks related to the consumption of alcohol.