title: Antibrowning activity of MRPs in enzyme and fresh-cut apple slice models.
abstract: The present study examined various types of Maillard reaction products (MRPs) for their inhibitory effect on mushroom tyrosinase. Results showed that monosaccharide-GSH (glutathione) but not polysaccharide-GSH derived MRPs were more active than GSH in inhibiting mushroom tyrosinase. However, in fresh-cut apple slice model, surprisingly GSH performed much better than sucrose-GSH derived MRPs when the apple slices were stored at room temperature for 24h. Further time-course study did find deterioration in tyrosinase mushroom inhibitory activity of sugar-GSH derived MRPs over time, suggesting the formed tyrosinase inhibitors in MRPs are unstable. Different combinations of chemical agents with sucrose-GSH derived MRPs were also investigated on apple slices. A synergistic effect was observed when sucrose-GSH derived MRPs (3.125mM) were applied in combination with 0.5% ascorbic acid. Apart from instability of principal inhibitors, observation of an unpleasant odor from apple slices treated with MRPs raised another concern about the probable negative impact of these inhibitors on the sensory quality of food products. Our research indicates the limited application of MRPs as antibrowning agents for food products.
authors.affiliation: Department of Phytochemistry, China Pharmaceutical University, Nanjing 210038, PR China; School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, PR China.
authors.forename: Jia-Jun
authors.initials: JJ
authors.lastname: Wu
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, PR China.
authors.forename: Ka-Wing
authors.initials: KW
authors.lastname: Cheng
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, PR China.
authors.forename: Edmund T S
authors.initials: ET
authors.lastname: Li
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, PR China. Electronic address: mfwang@hkusua.hku.hk.
authors.forename: Mingfu
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Phytochemistry, China Pharmaceutical University, Nanjing 210038, PR China.
authors.forename: Wen-Cai
authors.initials: WC
authors.lastname: Ye
keywords: Maillard reaction products; Sensory quality; Synergistic effect; Thiol compounds; Tyrosinase inhibitors