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Some Characteristics of Eggplant and Avocado Polyphenolases
Author(s) -
KNAPP F. W.
Publication year - 1965
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.1365-2621.1965.tb01867.x
Subject(s) - catechin , hydroquinone , chemistry , chlorogenic acid , resorcinol , substrate (aquarium) , chelation , carbamate , thiourea , catechol , nuclear chemistry , stereochemistry , food science , organic chemistry , polyphenol , antioxidant , biology , ecology
SUMMARY Eggplant polyphenolase oxidized chlorogenic acid much faster than it did any other substrate. In contrast, the substrate oxidized most rapidly by the avocado preparation was nordi‐hydroguaiaretic acid (NDGA), followed by catechin and catechin. Resorcinol was a moderately effective competitive inhibitor ( K t = 0.02 M ), whereas hydroquinone ( K t = 0.005 M ) was a slightly less potent noncompetitive inhibitor. All the chlorides tested depressed eggplant polyphenolase activity to a similar but limited extent. The copper‐chelating agents 1‐phenyl‐2‐thiourea and sodium diethyldithio‐carbamate were powerful inhibitors; the former ( K t = 0.01m M ) was shown to act non‐competitively.