This study aimed to determine the optimal method by analyzing how different fining agents affect the quality of Muscat of Alexandria (MoA) wine. In the initial investigation, MoA wine underwent treatment with bentonite, egg white, icing glass, polyvinylpolypyrrolidone (PVPP), silica, and gelatin. General quality characteristics (pH, total acidity, sugar content, specific gravity, alcohol, volatile acidity), functional components (total polyphenols, antioxidant activity, tannins), and L*, a*, b* values were analyzed. Following the analysis, bentonite demonstrated the best color improvement, while silica and gelatin exhibited high total acidity and effective color enhancement. Consequently, bentonite, gelatin, and silica were deemed suitable for MoA wine and were selected for further investigation. In the second clarification test, varied experiments were conducted on bentonite, silica, and gelatin selected in the first clarification test. Analysis of general quality characteristics and functionality by fining type and time after treatment for MoA wine showed no significant changes before and after treatment. However, an analysis of turbidity after 8 months for each fining agent revealed a superior turbidity improvement effect of 0.040 ± 0.001 in the bentonite treatment group. Additionally, the L value was favorable in the bentonite and silica treatments. Regarding the improvement effect of the b value, silica treatment demonstrated the best results, followed by gelatin treatment.

This study investigated quality characteristics and functionality of rose sparkling wine that were manufactured by secondary fermentation after inoculation of yeast strains. The pH of the samples ranged from 3.96 to 4.05 and total acidity ranged from 0.23 to 0.32%. The alcohol contents of wines ranged from 6.4 to 6.6% and the CO2 pressure ranged from 2.0 to 2.6 bar. The brightness of rose wines ranged from 84.72 to 87.36, the redness from 9.28 to 14.15, and the yellowness from 9.50 to 19.20. The hue value of wines ranged from 1.137 to 1.513 and color intensity ranged from 0.724 to 0.882. Aroma analysis identified 14 alcohols, 22 esters, 4 ketones, 4 acids, and 17 miscellaneous compounds. The total tannin contents and total polyphenol contents of wines were 11.28~12.43 mg% and 24.79~28.20 mg%, respectively. The DPPH radical scavenging activity of wines ranged 63.33 to 67.89% and the ABTS radical scavenging activity of wines 82.16~86.06%. The results of this study provide a basis for establishing the brewing process of rose sparkling wines yeast strains.

Low alcohol (6%) wines were manufactured using Campbell Early. To develop the sterilization process of low alcohol wines, red wines were heat sterilized, and rose wines were nonthermal sterilized by concentration using potassium metasulfite and potassium sorbate. Samples were stored at 25℃ and quality characteristics were investigated by period. Results of this study revealed the pH of the samples after sterilization ranged from 3.15 to 3.19, and the total acidity of wines ranged from 0.011 to 0.024%. The free SO2 contents of wines ranged from 13.00 to 29.678 mg/L, and the total SO2 contents of wines ranged from 47.50 to 121.00 mg/L. L (lightness) of wines decreased whereas a (redness) and b(yellowness) increased. The hue value of wines ranged from 0.52 to 1.03, and decreased significantly(not including rose sweet wines). The color intensity of red and rose dry wines after sterilization increased, whereas red and rose sweet wines decreased. The DPPH radical scavenging activity of red wines and rose wines ranged between 75.50 to 89.23%, and 36.60 to 56.54%, respectively. The total polyphenol contents were 57.51~182.63 mg%. Results of this study provide scientific information to establish the sterilization process of low alcohol wines.