3.2. Effect of oxalic acid on fruit surface browning
As shown in Fig. 2, the fruit displayed browning followed with the ripening process and there was yellow color accumulation from 12 day in control fruit. The brown index of the fruit treated with 8 and 20 mM oxalic acid was 52.78% ± 5.6% and 50.00 ± 4.0%, respectively, while the untreated fruit was as high as 75.00 ± 7.8% at the end of storage. This demonstrated that the oxalic acid could reduce or delay the browning burst (Fig. 3). A comparison of the inhibitory influence of different oxalic acid concentrations on browning showed that 8 and