Papain from ripe fruit and from papaya latex was characterised, in comparison with stem bromelain, under wine-like
conditions, with the aim to evaluate their applicability for white wine stabilization.
Papains proteolytic activity was investigated, in McIlvaine buffer toward different synthetic peptide substrates
and Bz-Phe-Val-Arg-pNA appeared the most suitable one for detecting proteolytic effect at wine average minimum
pH (3.2). Kinetic parameters estimated in McIlvaine (as reference) and in tartaric buffer (mimicking wine medium),
indicated a good hydrolytic activity toward selected substrate, at wine average minimum pH value (3.2) in spite of
ethanol presence, in both mediums. Papain from latex showed a significantly higher and stable catalytic activity
respect to fruit papain and stem bromelain, retaining after 7 days, about 50% of its initial activity