It is well documented that CA can be easily oxidized to its quinone
form in a basic environment, and that subsequent polymerization
of the quinones will result in the browning process
(Antolovich et al., 2004). However, in our previous study (Lu,
Luo, Feng, & Turner, 2007), an aqueous SC solution at pH 8.5 also
exhibited certain anti-browning effects on fresh-cut apples,
although the inhibitory effect was weaker than that of SC in acidic
condition (pH 4.6). Thus, the reaction of CA (0.1 mM) with SC
(3.0 mM) was further investigated without adjusting pH. The initialmechanisms. The browning reaction of chlorogenic acid catalyzed
by PPO was inhibited by sodium chlorite. It was further found that
the incubation of SC and PPO resulted in enzyme inactivation, and
that the reaction occurred between SC and CA led to the degradation
of CA. Therefore, the anti-browning property of sodium chlorite
could be attributed to two modes of action, i.e., direct
inactivation of PPO and oxidative degradation of the phenolic substrates.
We expect that by providing an understanding of the
mechanism by which SC inhibits enzymatic browning, this research
will help to accelerate the adoption of SC as a dual control
by the fresh-cut produce industry, thus promoting improved quality
and safety of fresh-cut produce.