YEAST INHIBITION IN GRAPE JUICE CONTAINING SULFUR-DIOXIDE, SORBIC ACID, AND DIMETHYLDICARBONATE

Sulfur dioxide (SO2), sorbic acid (SB), dimethyldicarbonate (DMDC), and their combinations were studied for suppression of fermentation at 21-degrees-C or 31-degrees-C in grape juice inoculated with 2, 200, or 20,000 colony forming units (CFU)/mL of yeast. The other preservatives did not suppress as well as DMDC. The DMDC (0.8 mM) prevented fermentation at all inoculation levels at both temperatures, except that inoculated with 20,000 CFU/mL at 21-degrees-C. The 0.8-mM level of SO2 + DMDC, and SB + DMDC prevented fermentation in samples inoculated with 2 or 200 CFU/mL at 31-degrees-C. Storage at 31-degrees-C decreased effectiveness of SO2, SB, and SO2 + SB but increased effectiveness of DMDC, SO2 + DMDC, and SB + DMDC (0.8 mM level).