Reduction of postharvest rind disorders in citrus fruit by modified atmosphere packaging
Ron Porat, Batia Weiss, Lea Cohen, Avinoam Daus and Nehemia Aharoni
Postharvest Biology and Technology Volume 33, Issue 1 , July 2004, Pages 35-43
2004
บทคัดย่อ
Citrus fruit are relatively non-perishable, and can normally be stored for long periods of 6–8 weeks. However, the development of various types of rind disorders limits the postharvest storage capability, and causes massive commercial losses. In the present study, we found that modified atmosphere packaging (MAP) in "bag-in-box" Xtend® films (XF) effectively reduced the development of chilling injury (CI) as well as other types of rind disorders that are not related to chilling, such as rind breakdown, stem-end rind breakdown (SERB) and shriveling and collapse of the button tissue (aging). In all cases, microperforated films (0.002% perforated area) that maintained CO2 and O2 concentrations of 2–3 and 17–18%, respectively, inside the package were much more effective in reducing the development of rind disorders than macroperforated films (0.06% perforated area), which maintained CO2 and O2 concentrations of 0.2–0.4 and 19–20%, respectively. In both types of package, the relative humidity (RH) was ~95%. No major differences were found between the effectiveness of polyethylene (PE) and XF packages, despite the fact that XF prevents water condensation inside the bags. Overall, microperforated and macroperforated XF packages reduced rind disorders not related to chilling (rind breakdown, SERB and aging) after 5 weeks of storage at 6 °C and 5 days of shelf life conditions by 75 and 50%, respectively, in ‘Shamouti’ orange, and by 60 and 40%, respectively, in ‘Minneola’ tangerines. Similarly, microperforated and macroperforated XF packages reduced the development of CI after 6 weeks of cold storage at 2 °C and 5 days of shelf life conditions by 70 and 35%, respectively, in ‘Shamouti’ oranges and by 75 and 45%, respectively, in ‘Star Ruby’ grapefruit. Furthermore, storage of unwrapped ‘Shamouti’ oranges in high RH (95%) also reduced rind disorders by 40–50%, similarly to the effects of the macroperforated films. In the light of these data, we suggest that MAP reduces the development of rind disorders in citrus fruits via two modes of action: the first, which is common to both microperforated and macroperforated films is by maintaining the fruit in a high RH environment; the second, which is specific to the microperforated film, involves maintaining a modified atmosphere environment with elevated CO2 and lowered O2 levels.
Author Keywords: Chilling injury; Citrus; Modified atmosphere; Postharvest; Rind breakdown