The half lives of polyphenol oxidase and trypsin at 50% (v/v) co-solve
nt (water miscible) were from 23 to 176 h when polarity index of the c
o-solvent was >5.8 or if the cc-solvent was an alcohol. Polyphenol oxi
dase, trypsin, chymotrypsin and beta-glucosidase lost only 10% activit
y in such water/organic co-solvent mixtures when the organic co-solven
ts were present in the concentration ranges of 55-90%, 60-78%, 15-70%
and 7-25% respectively.