Meijiao Hu

Low-temperature conditioning induces chilling tolerance in stored mango fruit.

In this study, mango fruit were pre-treated with low-temperature conditioning (LTC) at 12°C for 24h, followed by refrigeration at 5°C for 25days before removal to ambient temperature (25°C) to investigate the effects and possible mechanisms of LTC on chilling injury (CI). The results showed that LTC effectively suppressed the development of CI in mango fruit, accelerated softening, and increased the soluble solids and proline content. Furthermore, LTC reduced electrolyte leakage, and levels of malondialdehyde, O2- and H2O2, maintaining membrane integrity. To reveal the molecular regulation of LTC on chilling tolerance in mango fruit, a C-repeat/dehydration-responsive element binding factor (CBF) gene, MiCBF1, was identified and its expression in response to LTC was examined using RT-qPCR. LTC resulted in a higher MiCBF1 expression. These findings suggest that LTC enhances chilling tolerance in mango fruit by inducing a series of physiological and molecular responses.

Effect of postharvest spray of apple polyphenols on the quality of fresh-cut red pitaya fruit during shelf life

Fresh-cut (FC) red pitaya fruit were treated with 5ga.i.l-1 apple polyphenols (APP) and then stored at 20°C for up to 4days to evaluate the effects on attributes. Results showed that FC pitaya fruit with APP treatment showed greater colour retention, delayed softening, reduced loss of soluble solids content, titratable acidity, betacyanin and total phenolics compared with untreated FC fruit. APP treatment also maintained antioxidant activity, as indicated by higher DPPH radical-scavenging activity and reducing power compared with untreated FC pitaya fruit. APP treatment strongly suppressed microbial growth, contributing to improvement of product safety. Because APP is a natural product, we propose that application of APP could be a convenient, safe and low-cost approach to maintain the quality and extend the shelf life of FC red pitaya fruit.