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Objective: This study aimed to explore the effects of different concentrations of dissolved oxygen and free SO2 on the color and related parameters of Cabernet Sauvignon dry red wine during aging, and to provide basic data for enterprises to improve the aging process of Cabernet Sauvignon dry red wine. Methods: Cabernet Sauvignon dry red wine from Xinpuwang Wineyard in Shanshan County, Turpan, Xinjiang was used as the brewing material. The effects of different concentrations of free SO2 and dissolved oxygen on wine color, hue and anthocyanin content were observed during wine aging. Results: The wine was bright red when the concentration of dissolved oxygen and free SO2 was low. When the content of oxygen was 2 mg/（L·30 d）, the moderate polymerization of anthocyanin and tannin in wine was promoted, and the quality of the wine was improved. When the concentration of free SO2 was 15 ~ 30 mg/L, it had little effect on the hue value of grape wine, but it had an obvious effect on the color. When the concentration of free SO2 was more than 30 mg/L, the color of grape wine gradually became orange. Conclusion: The suitable concentration of free SO2 for Cabernet Sauvignon dry red wine aging was 25 mg/L, and the oxygen content was 2 mg/（L·30 d）.

Transferring wine is a common operation in most of the wineries in the world that depends mainly on the equipment and materials used. These contributions are widely unknown, and their knowledge is of vital importance to controlling the winemaking process. This work presents the results of characterizing the oxygen supply due to the use of hoses of different materials (Butyl Rubber, IIR; Nitrile Butadiene Rubber, NBR; Ethylene Propylene Diene Monomer rubber, EPDM; Ultra-high-molecular-weight polyethylene, UHMW; Natural Rubber, NR), dimensions (DN32; DN50), connectors (DIN 11851, Tri-CLAMP) with gaskets of different materials (NBR; EPDM; Fluorocarbon, FKM/FPM; silicone rubber, Q/VMQ; Polytetrafluoroethylene, PTFE). In addition, the use of different inert gases (N2, CO2, Ar, N2 + CO2 and Ar + CO2) for air purging of hoses and tanks, as well as for ullage blanketing during tank-to-tank racking, and their economic impact were studied. The results indicated that the IIR hoses had the least amount of O2 added to the liquid and that the Tri-clamp connectors were generally more airtight, with the FKM seals standing out. The most recommended inert gas was CO2 when the type of wine allows it, N2 being the most recommended in any case. When all these recommendations were used together the addition of O2 during tank-to-tank racking was drastically reduced.

• A method was developed for free sulfur dioxide analysis in wine and ciders using capillary electrophoresis. • Minimal sample preparation is required. • Samples are analyzed at pH 3.0, which avoids the issue of artificially high values in pigmented samples. • The method was validated in both unpigmented and pigmented wine and cider samples. • The method is fast, sensitive, and repeatable. A novel method for the determination of "true" free sulfur dioxide (SO 2) in wine and cider was developed using capillary electrophoresis with direct ultraviolet-visible spectrophotometric detection (CE-UV/vis). Free SO 2 was measured in model solutions with different SO 2 -binding agents present (α-ketoglutarate, pyruvate, acetaldehyde, glucose, fructose, and malvidin-3-glucoside) as well as a variety of white and red wines and ciders. The CE method was compared to three conventional methods for measuring free SO 2 , the Ripper method, Aeration-Oxidation (AO), and pararosaniline by discrete analyzer (DA). While some statistically significant differences (p <0.05) were found between the four methods in unpigmented model solutions and samples, the values generally agreed. In the presence of anthocyanins in model solution and red wines, free SO 2 values found by CE were significantly lower than the other three methods (p <0.05). The difference in values found by Ripper and CE correlated strongly with anthocyanin content (R2 = 0.8854) and even more strongly when accounting for polymeric pigments (R2 = 0.9251). The results in red ciders differed from those in red wines, while the CE measured significantly lower free SO2 values than the other three methods, the difference in free SO 2 values measured by CE and Ripper correlated more closely with anthocyanin concentration (R2 = 0.8802) than absorbance due to bleachable pigment (R2 = 0.7770). The CE method was found to be rapid (4 min/injection), sensitive (LOD=0.5 mg/L, LOQ=1.6 mg/L free SO 2 in wine, 0.8 and 2.8 mg/L, respectively, in cider), robust, and repeatable (average RSD = 4.9%) and did not suffer from the issue of over-reporting free SO 2 in pigmented samples often observed with currently accepted methods. [ABSTRACT FROM AUTHOR]

Transferring wine is a common operation in most of the wineries in the world that depends mainly on the equipment and materials used. These contributions are widely unknown, and their knowledge is of vital importance to controlling the winemaking process. This work presents the results of characterizing the oxygen supply due to the use of hoses of different materials (Butyl Rubber, IIR; Nitrile Butadiene Rubber, NBR; Ethylene Propylene Diene Monomer rubber, EPDM; Ultra-high-molecular-weight polyethylene, UHMW; Natural Rubber, NR), dimensions (DN32; DN50), connectors (DIN 11851, Tri-CLAMP) with gaskets of different materials (NBR; EPDM; Fluorocarbon, FKM/FPM; silicone rubber, Q/VMQ; Polytetrafluoroethylene, PTFE). In addition, the use of different inert gases (N2, CO2, Ar, N2 + CO2 and Ar + CO2) for air purging of hoses and tanks, as well as for ullage blanketing during tank-to-tank racking, and their economic impact were studied. The results indicated that the IIR hoses had the least amount of O2 added to the liquid and that the Tri-clamp connectors were generally more airtight, with the FKM seals standing out. The most recommended inert gas was CO2 when the type of wine allows it, N2 being the most recommended in any case. When all these recommendations were used together the addition of O2 during tank-to-tank racking was drastically reduced. [ABSTRACT FROM AUTHOR]