Immobilized yeasts in kappa-carragenate to prevent browning in white wines.

摘要

Yeasts immobilized in kappa-carragenate gel beads of variable size were used to delay accelerated browning of sherry pale white wines at 35 degrees C. Based on the results, the wines maintained in contact with no gel took 27 days to reach the browning limit level for commercial wines of this type (A420 value of 0.180 au). However, wines containing gel beads 1, 2 or 3 mm thick reached such a level 24, 30 and 33 days later, respectively, than the control samples. After 27 days of contact with gel beads, the wines exhibited decreased contents of phenolic acids, hydroxycinnamic esters and flavan-3-ol monomers and dimers. On the other hand, the yeast gels substantially delayed browning of wines stored at 19 degrees C in bottles for 1 yr. Thus, while the wines stored without gels reached the commercial rejection limit for A420, those stored in contact with gel beads exhibited virtually no browning and only slight changes in their sensory properties, and they were still acceptable for consumption.