Effect of Chitosan-Mangosteen Peel Composite Coating on Blueberry Preservation

The ‘Northland’ blueberry fruits were treated with 0.5% chitosan (chitosan, CTS) or 0.5% chitosan (chitosan, CTS) composite 1% mangosteen peel extracts (mangosteen peel extracts, MPE) and then stored at low temperature (4±0.2) ℃. The physiological indexes related to storage quality and antioxidant capacity of blueberry fruit during storage were determined. The results indicated that compared with the control, CTS treatment and CTS combined with MPE treatment could slow down the decrease of firmness, soluble solids (TSS) content and water content of blueberry fruits during storage. In CTS-treated and CTS combined with MPE-treated fruits, the appearance of respiratory peak was delayed by seven days than the control. Both CTS treatment and CTS combined with MPE treatment could slow down the decreasing of vitamin C (V_C) contents and total phenol contents, and at the same time, delay the increasing of malondialdehyde (MDA) contents. During the late storage period (49 d), CTS combined with MPE treatment still maintained a higher level of DPPH· and ABTS⁺· free radical scavenging rate, which were 8.9% and 20.3% higher than the control, respectively, thus maintaining the antioxidant capacity of blueberry fruits. Among these three treatments, CTS combined with MPE treatment was the best. In conclusion, CTS combined with MPE coating treatment could effectively maintain the storage quality and antioxidant activity of blueberry fruits, and thus delayed its ripening and senescence process.