4. Conclusion
PPO activity in crude extracts of Ataulfo mango was observed
for di- and tri-phenolic substrates with pH optima between pH
5.4 and pH 6.4. The enzyme was fairly thermo-stable, but can be
inhibited effectively with sodium ascorbate in millimolar concentrations.
L-Ascorbic acid is listed as a GRAS compound by the FDA
(FDA, 2014). GRAS stands for ‘‘Generally Recognized As Safe’’.
Fig.