Juice fining treatments to reduce browning and use of sulfur dioxide in white wine production.

摘要

Sulfur dioxide (SO{dollar}sb2{dollar}) is used in juice and wine to control browning, but SO{dollar}sb2{dollar} has side effects that are unhealthy for man as well as problematic in wine production. Four factorial studies were conducted to study browning and color loss in juice and white wine when additives other than SO{dollar}sb2{dollar} were used prior to fermentation.; In study one, nine additives (ascorbic acid, ascorbic acid plus Sporix{dollar}sp{lcub}rm TM{rcub}{dollar}, cinnamic acid, EDTA, hydrogen sulfide, Cufex{dollar}spcircler{dollar}, bentonite, nitrogen sparge, SO{dollar}sb2{dollar}) and a control were studied. Ascorbic acid treatments produced wines that were more brown than the control. Nitrogen sparged, Cufex and bentonite treated juice produced wines that were less brown than the control. All treatments were more brown than the SO{dollar}sb2{dollar} treatment.; In study two, two levels each of SO{dollar}sb2{dollar}, Cufex and bentonite were applied to juice. Wines had either 0 or 20 mg/L SO{dollar}sb2{dollar} applied at bottling and were stored at elevated temperature. Both levels of Cufex and bentonite produced wines that were less brown than the control, but more brown than the SO{dollar}sb2{dollar} treatment.; In study three, fining agents were added to reduce juice phenols. Bentonite, kieselsol, and polyvinylpolypyrrolidone (PVPP) were added alone or in combination to juice; SO{dollar}sb2{dollar} and a untreated control were also used. Bentonite containing treatments reduced the catecholase activity in the juice, through precipitation, to the same extent as SO{dollar}sb2{dollar}. The amount of each compound used alone was adjusted to reduced total juice phenols by 10%. The bentonite plus PVPP treatment reduced total juice phenols by 30% and produced wine similar in color to the SO{dollar}sb2{dollar} juice treatment. All bentonite containing treatments reduced flavonoid phenolics while leaving non-flavonoid phenolics unaffected. A high performance liquid chromatogram did not indicate a reduction in specific phenols but rather a general decrease in phenolics.; In study four, bentonite was applied to juice, during-fermentation and to juice plus during-fermentation. The latter treatment produced a wine with color as good as or better than a wine made with 100 mg/L SO{dollar}sb2{dollar} added to juice. Phenolic profiles were similar to those in study three.