| 1. |
- Osorio-Macías, Daniel E., et al.
(författare)
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Characterization on the impact of different clarifiers on the white wine colloids using Asymmetrical Flow Field-Flow Fractionation
- 2022
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Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146. ; 381
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Tidskriftsartikel (refereegranskat)abstract
- Clarifiers are substances used during the winemaking process to enhance clarity and stability in the wines. The different clarifiers may alter removal capacities differently. In this study, the removal efficiency of seven common fining agents, divided into three groups (mineral clarifiers, synthetic polymeric clarifiers, and vegetable protein clarifiers), was analyzed with Asymmetrical Flow Field-Flow fractionation (AF4). Besides, the relationship between the removal capacity and different molecular and macromolecular properties has been evaluated. The results showed extensive removal of colloidal and macromolecular matter by the bentonites with potential impact on characteristic properties of the wine. The vegetable clarifiers showed a more profiled reduction, potentially preserving characteristics of the wine. The synthetic polymers showed a more limited removal efficiency but with a high affinity to remove colloidal phenols. The use of AF4-UV-MALS-dRI allowed the characterization of the wines after different clarification treatments, showing to be an analytical technique with a potential impact on the wine industry.
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| 2. |
- Osorio-Macías, Daniel E., et al.
(författare)
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Fractionation of Nanoparticle Matter in Red Wines Using Asymmetrical Flow Field-Flow Fractionation
- 2020
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 68:49, s. 14564-14576
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Tidskriftsartikel (refereegranskat)abstract
- The particle matter of wine is mainly composed of wine colloids and macromolecules. The present work develops a methodology using asymmetrical flow field-flow fractionation coupled with multi-angle light scattering, differential refractive index detector, and ultraviolet detector (AsFlFFF−MALS−dRI−UV) for the fractionation and determination of the molar mass, the hydrodynamic radius, and the apparent densities of the aggregates and macromolecules present in wine samples. The results from a set of six Argentinian high-altitude wines showed two main populations: the first population composed of wine colloids with higher UV-specific absorptivity and the second population composed of polysaccharides, such as arabinogalactans. The conformation results showed that population 1 consists of small and dense particles, while population 2 showed high molar masses and lower densities. The results demonstrated the use of AsFlFFF as a new, effective method for the fractionation and characterization of wine colloids and wine macromolecules in red wines with further potential applications.
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| 3. |
- Osorio-Macías, Daniel E, et al.
(författare)
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Resveratrol, phenolic antioxidants, and saccharides in South American red wines
- 2018
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Ingår i: International Journal of Wine Research. - 1179-1403. ; 10, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Wine is an important beverage with a long tradition, and its moderate consumption may be considered beneficial for human health. Although there are many studies regarding phenolic compounds in wines, there is a lack of information about antioxidants and phenolic content in South American wines. In this study, 35 South American red wines from four different countries, vintages 2004–2013, purchased at retail stores in La Paz, Bolivia, were studied. Resveratrol content, total antioxidant capacity (TAC) by the 2,2′-azinobis(3-thylbenzotiazoline-6-sulfonic acid) (ABTS) and ferric-reducing antioxidant power (FRAP) methods, total phenolic content (TPH), total flavonoids (TF), and main saccharides were assessed using the well-established spectrophotometric and high-performance liquid chromatography methods. The results ranged from 4 to 24 mmol/L for TAC determined by ABTS method and 14 to 43 mmol/L for TAC determined by FRAP method, 1600 to 3500 mg gallic acid equivalents/L for TPH, and 2 to 6 mmol catechin equivalents /L for TF. The resveratrol content ranged from 0.1 to 8 mg/L. Saccharides, glucose, and fructose content ranged from 0.4 to 10 g/L, 1.4 to 8.6 g/L, and 0.2 to 12 g/L, respectively. There was a high correlation among the different methods. The results showed that some wines growing at high altitude (>1500 meters above the sea level) have higher amounts of TAC and phenolic content, including resveratrol, while non-varietal wines showed the lowest values. It was also observed that the saccharose content in some wines was surprisingly high, suggesting saccharose dosing after fermentation.
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