Characterization of tannins and prevention of light-struck taste: the Enofotoshield project
Daniela, FRACASSETTI, Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Via G. Celoria 2, 20133 Milan, Italy
Natalia, MESSINA, Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano
Rebecca, BODON, Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano
Alberto, SALIGARI, Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano
Antonio, TIRELLI, Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano
Email contact: daniela.fracassetti[@]unimi.it
AIM: Hydrolysable tannins resulted effective against the formation of light-struck taste (LST) in model wine [1]. The first activity of Enofotoshield project is to evaluate the effectiveness of tannins in limiting the LST in white wine. Therefore, tannins of different origin were characterized in terms of their chemical composition as well as their ability in preventing the appearance of LST that was firstly screened in model wine.
METHODS: Fifteen commercial tannin-based formulas of different origin (grape skin and seeds, tea, oak, chestnut, cherry, acacia, quebracho, tara, nut gall, lemon) and extraction treatment (e.g. water, solvent) were considered. They were characterized in terms of total phenolics (Folin-Ciocalteau index and 280 nm; TPI), antioxidant capacity (DPPH assay), relative amounts of oxidized phenols, ellagitannins and proanthocyanidins content, the latter two for hydrolysable and condensed tannins, respectively. The oxygen consumption rate was assessed for all the formulas with and without sulfur dioxide. The impact on astringency and bitterness was also evaluated. The effectiveness against the appearance of LST was assessed in model wine solution added with the two actors of LST, riboflavin and methionine (Met), in both oxic and anoxic conditions.
RESULTS: The tannin-based formulas showed a wide content of phenolics ranging from 462±28 to 1019±57 mg gallic acid/g powder for cherry tannins and gall nut tannins, respectively. Similarly, the antioxidant capacity strongly varied from 3.70±0.23 mM Trolox/g powder for grape skin tannins to 10.94±1.28 mM Trolox/g powder for nut gall tannins. Considering the ratio among the antioxidant capacity and TPI, tara tannins showed the greatest value. The oxygen consumption rate also differed and it was the lowest and the highest in the presence of and nut gall and chestnut tannins, respectively, when sulfur dioxide was not added. None of them affected both bitterness and astringency in white wine (up to 80 mg/L). Met decreased in all the conditions tested due to the light exposure and an increase of Met sulfoxide, the major compound deriving from Met oxidation [2], was observed. Sniffing trials showed the ability of most of these formulas in preventing the LST; some of the tested tannin preparations revealed only little differences in LST perception between oxic and anoxic conditions.
CONCLUSIONS: Tannins can effectively prevent the appearance of LST. The tannin-based formulas with the best performances in terms of LST prevention and lowest impact on wine properties will be employed at bottling for the wine production at industrial scale.
References:
[1] Fracassetti et al., 2019. doi: 10.1016/j.foodchem.2019.124952
[2] Fracassetti et al., 2020. doi: 10.1021/acsomega.0c03845.
Acknowledgment: The research is financially supported by Regione Lombardia - Piano di Sviluppo Rurale (Italy), Enofotoshield Project (D.d.s. 1 luglio 2019 - n. 9551, B.U.R.L. Serie Ordinaria n. 27 - 04 luglio 2019).
________________________________________________________________________________________________
Monitoring the Tawny Port wine aging process using precision enology
Fernanda Cosme - Chemistry Research Centre - Vila Real (CQ-VR), Food and Wine Chemistry Lab, University of Trás-os-Montes and Alto Douro, 5001-801 Vila Real, Portugal.
Raul Morais - INESC TEC – Campus da FEUP, Porto, Portugal and UTAD – University of Trás-os-Montes and Alto Douro, 5000-801 Vila Real, Portugal
Emanuel Peres - INESC TEC – Campus da FEUP, Porto, Portugal and UTAD – University of Trás-os-Montes and Alto Douro, 5000-801 Vila Real, Portugal
José Boaventura Cunha - INESC TEC – Campus da FEUP, Porto, Portugal and UTAD – University of Trás-os-Montes and Alto Douro, 5000-801 Vila Real, Portugal
Jorge Mendes - INESC TEC – Campus da FEUP, Porto, Portugal and UTAD – University of Trás-os-Montes and Alto Douro, 5000-801 Vila Real, Portugal
LuÃs Filipe-Ribeiro - Chemistry Research Centre - Vila Real (CQ-VR), Food and Wine Chemistry Lab, University of Trás-os-Montes and Alto Douro, 5001-801 Vila Real, Portugal.
Fernando M. Nunes - Chemistry Research Centre - Vila Real (CQ-VR), Food and Wine Chemistry Lab, University of Trás-os-Montes and Alto Douro, 5001-801 Vila Real, Portugal.
Email contact: fcosme@utad.pt
AIM: Tawny Port wine is produced in the Douro Demarcated Region by blending several fortified wines in different aging stages. During the aging process in small wood barrels, the red wine color progressively develops into tawny, medium tawny, or light tawny. In this Port wine style, there are some special categories like Tawny Reserve, Tawny with Indication of Age (10, 20, 30, and 40 years), and “Colheita” that are commercialized worldwide. This last category is an exception, as these wines are from a single vintage [1]. In Tawny Port wine the oxidative aging process is multifactorial and critical for reaching the required quality. So, real-time monitoring of important intrinsic and extrinsic factors known to impact both wine quality and aging time are important to optimize and to manage the natural inconsistency among wines aged in diverse long-used wood barrels. This work shows the design, development, and implementation of a remote distributed system to monitor factors that are identified to be critical for the Tawny Port wine aging process.
METHODS: The Tawny Port wine aging process was monitored in two equal wineries – one of them with controlled temperature– in Vallegre, Porto S.A.. Barrels were instrumented with sensors to measure parameters during the aging process, specifically: pH, redox potential, dissolved oxygen, and temperature. The monitoring process was done using an RS-485 industrial network, which interconnects the mentioned sensors [2].
RESULTS: The distributed monitoring system was capable to detect differences among barrels and among the different storage conditions (controlled and room temperature). Redox potential and dissolved oxygen were the wine’s parameters where the differences among the different barrels were higher under the same storage conditions. Since the Tawny Port wine aging process is oxidative, a variation in the wine’s aging process among barrels is to be expected. Significant differences were detected in the oxygen consumption rate among the different barrels. Differences in the phenolic composition were also observed in the aged wine, both at controlled and room temperature.
CONCLUSIONS: Results indicated that the distributed monitoring system was capable to detect variations among barrels and among both storage conditions: controlled and room temperature. Actually, redox potential and dissolved oxygen were the wine’s factors where the variances found were higher among wood barrels, while under the same storage conditions. This methodology is based on easy-to-use implanted systems, with the intention of giving an important contribution to other projects in the area of precision enology.
The authors want to acknowledge FCT Portugal for funding the CQ – VR through the grant (UIDB/00616/2020 and UIDP/00616/2020), to project INNPORT “Otimização do processo de envelhecimento do vinho do Porto Tawny” and Vallegre Company.
References:
[1] Milheiro, J., Cosme, F., Filipe-Ribeiro, L., Nunes, M. N. (2020). Port Wine: Production and Ageing, IntechOpen. Available from. https://www.intechopen.com/online-first /port-wine-production-and-ageing.
[2] Morais, R., Peres, E., Boaventura-Cunha, J., Mendes, J., Cosme, F., Nunes, F. M. Comput Electron Agric. 145, 92 (2018).
__________________________________________________________________________________________________
White wine light-strike fault: a comparison between flint and green bottles under the typical supermarket conditions
Panagiotis ARAPITSAS, Department of Food Quality and Nutrition, Research and Innovation Centre Fondazione Edmund Mach, San Michele all’Adige, Italy
Silvia, CARLIN, Department of Food Quality and Nutrition, Research and Innovation Centre Fondazione Edmund Mach, San Michele all’Adige, Italy.
Stefano, DALLEDONNE, Department of Food Quality and Nutrition, Research and Innovation Centre Fondazione Edmund Mach, San Michele all’Adige, Italy.
Matthias, SCHOLZ, Department of Food Quality and Nutrition, Research and Innovation Centre Fondazione Edmund Mach, San Michele all’Adige, Italy.
Antonio, CATAPANO, Wenda srl, Bologna, Italy.
Fulvio, MATTIVI, Department of Food Quality and Nutrition, Research and Innovation Centre Fondazione Edmund Mach, San Michele all’Adige, Italy. Bioorganic Chemistry Laboratory, Department of Physics, University of Trento, Trento, Italy
Email contact: panagiotis.arapitsas[@]fmach.it
AIM: Consumer preference favors flint-glass wine bottles over the traditional dark-colored, but it is documented that light exposure can cause white wines to produce off-aromas and change in color, and consequently
da[1]mage their quality. Aim of the study was to study the white wine shelf life under the typical supermarket conditions, by recording the light and temperature exposure, the colorimetric changes, and the light-strike fault.
METHODS: One pilot experiment based on two white wines and eight-time points and one kinetic experiment based on four white wines and seven-time points were designed and realized using a typical supermarket shelf for 32 and 50 days, correspondently. By installing prototype sensors at 32 points of the shelf, the temperature, UV, IR, and Visible light exposure were registered every 10 min. Approximately 600 commercial wines, bottled in flint and colored glass, were used. The colorimetric changes of the wines were registered and the light-strike fault was evaluated.
RESULTS: Generally, green glass bottles secured wine quality for the tested period. Only a few flint glass bottled wines developed the fault after 1-2 days of supermarket shelf life, but all developed the fault after 3-4 weeks. Storing the wines in dark and cold after a period of exposure to light did not eliminate the fault. A limit of up to 20-30 UVI of UV light passing through the glass could be set, considering the relative UV light in respect to the sensor measurements and the glass type. Moreover, wines bottled in flint glass after two days of shelf life had already lost more chromatic intensity and yellow hue than the same wines bottled in the green glass after 50 days.
CONCLUSIONS: Light-strike wine fault is irreversible, occurs in all white wines, even if some are more resistant than others are, and the dark colored glass bottle is the best solution to avoid the problem.
References:
Arapitsas P, Dalledonne S., Scholz M, Catapano A, Carlin S, Mattivi F. “White wine light-strike fault: A comparison between flint and green glass bottles under the typical supermarket conditions“ Food Packaging and shelf life 24, 100492 (2020).
______________________________________________________________________________________________________
Investigating the impact of bottle color, temperature and light exposure on rose wine characteristics
Cristina MEDINA-PLAZA/ University of California, Davis
Aubrey DUBOIS/ Oregon State University
Elisabeth TOMASINO/ Oregon State University
Anita OBERHOLSTER/ University of California, Davis
Email contact: cmedinaplaza[@]ucdavis.edu
Rose is leading the fastest growth wine category which hit a 40% increase since 2002. France accounts for over a third (34%) of global consumption followed by the US at 16%. The majority of rose wines are bottled in clear bottles. There are a range of factors that impact the selection of bottle color for wine storage, but consumer’s acceptance seems to be one factor where market forces drive the use of lighter colored glass bottles over dark green, brown or blue glass. Post-bottling storage is also a critical phase for rose wine. Bottled wine can be exposed to UV-visible light and temperature fluctuations for relatively long periods of time in retail stores, restaurants, and domestic settings, resulting in degradation with color and aroma changes.
This research studied the impact of bottle color, light exposure and temperature on rosé wine quality. Four rosé wines with different organoleptic characteristics and chemical compositions (color, phenolic, sugar and alcohol content) were bottled in clear and green bottles and stored under three different light conditions (darkness, fluorescent bulb and cool white LED bulb) at cellar (15 °C) and room temperature (20 °C). Color, basic chemical analysis, aroma profile, phenolics and reductive compounds were determined after 0, 3 and 6 months of storage. The color and phenolic composition were determined by spectrophotometric analysis and RP-HPLC. Potential changes in aroma were determined through volatile screening of the wines using SPME-GC-MS. Reductive compounds were also determined by SPME-GC-MS.
Changes in the wines were detectable after 3 months and more noticeable after 6 months of storage. Basic chemical analysis showed a decrease in free and total SO2 for all the samples analyzed with the largest impact found on the samples stored under fluorescent light. Regarding color, a decrease in intensity was found in the wines stored under both light conditions over time, particularly those in clear bottles. An increase in the percentage of yellow and a decrease in the percentage of red was significant in the wines stored at 20 °C under fluorescent light and more pronounced in the wines with lighter color/lower phenolic content. This may be due to oxidation reactions under these conditions. Wines stored in the dark showed no significant impact on color. These results were supported by RP-HPLC data, showing an increase in polymeric phenols and pigments and a decrease in monomeric anthocyanins. For aroma profiles significant changes were found between the starting wines and the different time points. When focusing on aroma only, bottle color showed a smaller impact than storage temperature.
Overall, all variables studied impacted rose wine aging significantly. However, higher temperature in combination with clear glass bottles under fluorescent light were the most detrimental to rose wine aging compared to low temperature and darkness that showed the smallest impact.
