Publicação
Understanding the need of SO2 in wine according to grape varieties
| Resumo: | The use of sulfur dioxide (SO2) is widely accepted as a useful aid in winemaking. It is used as a preservative due to its antioxidant and antimicrobial properties in wine. Although SO2 is a by-product of fermentation, most of the SO2 present in wines is added by the winemaker at different stages of the process. There is still controversy about the use of SO2 and its real impact on consumer health. Since 2005, the EU has required an indicative warning that there are sulfites in the product because a small minority of people are highly allergic to sulfites. However, information is scarce whether the SO2 requirement depends on the wine variety and to what extent. Furthermore, the search for replacers for this enological aid, while maintaining the quality of the final product has not yet been presented, behaving with the same multiplicity of actions. For this reason, SO2 is still one of the most effective tools winemakers has to protect wine and influence flavor. Thus, in this work one studied the volatile organic composition (VOC) of several varieties of wine obtained with controlled addition of different SO2, as well as its substitution or co-addition with ascorbic acid. Headspace solid phase microextraction gas chromatography/mass spectrometry (HS-SPME-GC/MS) was used for VOC analysis. To obtain a more comprehensive characterization of these wines, amino acid (AAs) profiles were accessed through High Performance Liquid Chromatography with Diode Array Detector (HPLC-DAD). The reduction of SO2 during the fermentation of the same must, resulted in different wines and the differences observed depend on the grape varieties used. This differentiation was observed shortly after the first 24 H of fermentation. However, these differences were reduced during stor-age. The same behavior was verified for ascorbic acid, which generally resulting in final products with different VOCs profiles. The results obtained indicate that any reduction in SO2 will interfere with the VOCs profile of the resulting wine, and thus may interfere with their flavor profile. The use of ascorbic acid as a substitute or co-additive did not lead to wines with the same profile as the wines treated only with SO2. Therefore, the use of these enological aids must be wisely considered as it will impact the final product. |
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| Autores principais: | Santos, Cátia Vanessa de Almeida |
| Assunto: | Wine Volatile Organic Composition (VOC) Amino acid Sulfur Dioxide (SO2) Ascorbic Acid HS-SPME-GC/MS |
| Ano: | 2022 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade Nova de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório Institucional da UNL |
| Resumo: | The use of sulfur dioxide (SO2) is widely accepted as a useful aid in winemaking. It is used as a preservative due to its antioxidant and antimicrobial properties in wine. Although SO2 is a by-product of fermentation, most of the SO2 present in wines is added by the winemaker at different stages of the process. There is still controversy about the use of SO2 and its real impact on consumer health. Since 2005, the EU has required an indicative warning that there are sulfites in the product because a small minority of people are highly allergic to sulfites. However, information is scarce whether the SO2 requirement depends on the wine variety and to what extent. Furthermore, the search for replacers for this enological aid, while maintaining the quality of the final product has not yet been presented, behaving with the same multiplicity of actions. For this reason, SO2 is still one of the most effective tools winemakers has to protect wine and influence flavor. Thus, in this work one studied the volatile organic composition (VOC) of several varieties of wine obtained with controlled addition of different SO2, as well as its substitution or co-addition with ascorbic acid. Headspace solid phase microextraction gas chromatography/mass spectrometry (HS-SPME-GC/MS) was used for VOC analysis. To obtain a more comprehensive characterization of these wines, amino acid (AAs) profiles were accessed through High Performance Liquid Chromatography with Diode Array Detector (HPLC-DAD). The reduction of SO2 during the fermentation of the same must, resulted in different wines and the differences observed depend on the grape varieties used. This differentiation was observed shortly after the first 24 H of fermentation. However, these differences were reduced during stor-age. The same behavior was verified for ascorbic acid, which generally resulting in final products with different VOCs profiles. The results obtained indicate that any reduction in SO2 will interfere with the VOCs profile of the resulting wine, and thus may interfere with their flavor profile. The use of ascorbic acid as a substitute or co-additive did not lead to wines with the same profile as the wines treated only with SO2. Therefore, the use of these enological aids must be wisely considered as it will impact the final product. |
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