α-Na8SiW11CoO40 was synthesized and characterized. The inhibitory effects of α-Na8SiW11CoO40 on the activity of mushroom tyrosinase and the effects of α-Na8SiW11CoO40 on the browning of fresh-cut apples were studied. The Native-PAGE result showed that α-Na8SiW11CoO40 had a significant inhibitory effect on tyrosinase. Kinetic analyses showed that α-Na8SiW11CoO40 was an irreversible and competitive inhibitor. The inhibitor concentration leading to a 50% reduction in activity (IC50) was estimated to be 0.239 mM. Additionally, the results also showed that α-Na8SiW11CoO40 treatment could significantly decrease the browning process of apple slices and inhibit the polyphenol oxidase (PPO) activity. Moreover, application of α-Na8SiW11CoO40 resulted in higher peroxidase activity and promoted high amounts of phenolic compounds and ascorbic acid. This study may provide a promising method for the use of polyoxometalates to inhibit tyrosinase activity and control the browning of fresh-cut apples.
Keywords: Ascorbic acid (PubChem CID: 54670067); Browning; Dimethyl sulfoxide (PubChem CID: 679); Electrophoresis analysis; Fresh-cut apples; Kinetics; Mushroom tyrosinase; Polyoxometalates; Tungstosilicic acid hydrate (PubChem CID: 71307034); l-3,4-Dihydroxyphenylalanine (PubChem CID: 6047); l-Tyrosine (PubChem CID: 6057).
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