It might be due
to the browning color of chitosan–glucose complex coating. The
color of grapes in all samples gradually became browner with
time. The browning of grapes was related to the action of polyphenol
oxidase (PPO) and pathogen infections. Previous studies have
demonstrated that CGC and chitosan coatings could effectively
inhibit spoilage organisms and responsible for PPO-mediated oxidation
of phenols to form melanin-like pigments, thus preventing
the formation of a brown undesirable appearance and improving
the visual appearance and color (Jiang et al., 2012; Liu et al., 2007).
When asked to show about overall preference, except day 15, all
panelists reported the fruit in CGC treatment was the most acceptability
at each assessed points, followed by chitosan and glucose.
All in all, chitosan–glucose complex could significantly maintain
sensory attributes of Muscat Hamburg during long-term storage,
as manifested by fruit visual appearance, color, flavor, taste and
overall preference.