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Inhibition of Mushroom Polyphenoloxidase by Ascorbic Acid Derivatives
Author(s) -
HSU A.F.,
SHIEH J.J.,
BILLS D.D.,
WHITE K.
Publication year - 1988
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1988.tb08951.x
Subject(s) - ascorbic acid , chemistry , dehydroascorbic acid , mushroom , substrate (aquarium) , vitamin c , acid phosphatase , biochemistry , enzyme , food science , oceanography , geology
ABSTRACT Ascorbic acid (AA), dehydroascorbic acid (dehydroAA), isoascorbic acid (isoAA), ascorbic acid‐2‐phosphate (AA‐2‐ PO 4 ), and ascorbic acid‐2‐sulfate (AA‐2‐SO 4 ) were tested as inhibitors of mushroom polyphenoloxidase (PPO). Kinetic analysis indicated that AA and isoAA were more effective than dehydroAA. The half times (t 1/2 ) that decreased 50% of PPO activity for AA, isoAA and dehydroAA were 2.5, 3.1, and 1.9 hr, respectively, and the concentrations that inhibited half of PPO activity were as follows: ascorbic acid, 0.04 mM, isoAA, 0.25 mM; and dehydroAA, 7.5 mM. Electron spin resonance studies demonstrated that the Cu 2+ of PPO was reduced to Cu + by AA. AA‐2‐PO 4 and AA‐2‐SO 4 were not inhibitors for PPO. However, the digestion of AA‐2‐PO 4 with acid phosphatase yielded AA to inhibit PPO activity. AA‐2‐SO 4 was found to be a poor substrate for sulfatase.