Rey Florencia, Zacarías Lorenzo, Rodrigo María J
Department of Food Biotechnology, Institute of Agrochemistry and Food Technology (IATA-CSIC), 46980 Valencia, Spain.
Antioxidants (Basel). 2020 Dec 17;9(12):1296. doi: 10.3390/antiox9121296.
Chilling injury (CI) is a postharvest disorder occurring in the fruit of cold-sensitive species during storage at low temperatures. This study investigated the involvement of carotenoids and vitamin C, two major antioxidants of citrus peel, and the antioxidant capacity in the CI susceptibility of mandarin fruit. To that end, the fruit of three commercial varieties, Fortune, Nova, and Nadorcott, with significant differences in CI susceptibility, were selected. By on-tree fruit bagging, carotenoids and vitamin C contents were modified, and a differential effect of each cultivar on CI was observed. Carotenoid analysis in the peel revealed a strong negative correlation between total carotenoid concentration (TCC) at harvest, and specifically of β-cryptoxanthin and violaxanthin, and CI index at the end of storage. In contrast, vitamin C content was significantly and positively correlated with CI susceptibility. The antioxidant activity assessed by the DPPH• and FRAP reflected the contribution of vitamin C to the antioxidant system, while the SOAC assay correlated positively with TTC, β-cryptoxanthin, and violaxanthin. Collectively, the antioxidant capacity of carotenoids at harvest, as efficient singlet oxygen quenchers, suggests a protective role against the development of CI in mandarin fruit, while vitamin C is not likely playing a critical role.
冷害（CI）是一种采后病害，发生在低温储存期间对冷敏感品种的果实上。本研究调查了柑橘果皮中两种主要抗氧化剂类胡萝卜素和维生素C的参与情况，以及抗氧化能力在柑橘果实冷害易感性中的作用。为此，选择了三个商业品种福琼、诺瓦和纳多特的果实，它们在冷害易感性上有显著差异。通过树上套袋，改变了类胡萝卜素和维生素C的含量，并观察到每个品种对冷害的不同影响。果皮中的类胡萝卜素分析显示，收获时的总类胡萝卜素浓度（TCC），特别是β-隐黄质和紫黄质的浓度，与储存末期的冷害指数之间存在强烈的负相关。相比之下，维生素C含量与冷害易感性呈显著正相关。通过DPPH•和FRAP评估的抗氧化活性反映了维生素C对抗氧化系统的贡献，而SOAC测定与TTC、β-隐黄质和紫黄质呈正相关。总体而言，收获时类胡萝卜素作为有效的单线态氧猝灭剂的抗氧化能力表明，其对柑橘果实冷害的发展具有保护作用，而维生素C不太可能发挥关键作用。
