Chirinos Rosana, Delgado-Pariona Jahaira, Aguilar-Galvez Ana, Figueroa-Merma Andrés, Pacheco-Ávalos Alejandro, Campos David, Pedreschi Romina
Instituto de Biotecnología, Universidad Nacional Agraria La Molina (UNALM), Av. La Molina s/n, La Molina, Lima 12056, Peru.
Programa de Investigación en Frutales, Universidad Nacional Agraria la Molina (UNALM), Av. La Molina s/n, La Molina, Lima 12056, Peru.
Plants (Basel). 2023 Nov 29;12(23):4008. doi: 10.3390/plants12234008.
The present study evaluated the performance of some enzymatic and non-enzymatic antioxidant systems against oxidative stress for 10 to 30 d of refrigeration (R) and 15 to 50 d in controlled atmosphere (CA) conditions in both exocarp and mesocarp of Hass avocados from early and late harvests and at shelf life (SL) or consumption maturity. The possible relationship of the antioxidant systems with the occurrence of physiological disorders is also evaluated. The results indicate that the enzymatic system-superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), phenylalanine ammonium lyase (PAL) and polyphenoloxidase (PPO)-as well as the non-enzymatic system-such as phenolic compounds (PC)-showed different responses to the stress generated during storage and shelf life. In general, SOD, CAT, PAL and PPO did not significantly vary in storage (R or CA). At consumption maturity, SOD, POD and PAL activities decreased in the mesocarp (RSL and CASL), while CAT increased in the exocarp for CASL15-50d. PC instead decreased in the exocarp as the harvest period progressed while it increased in the mesocarp. Physiological disorders (dark spots) showed only in refrigeration on the exocarp at R30d and in mesocarp at RSL30d coincident with low SOD and low SOD and POD activity values, as well as low PC contents (-coumaric and its derivatives and caffeic acid derivatives), respectively. The results support the use of CA as a postharvest technology to prevent the development of physiological disorders through the joint action of antioxidative defenses during avocado transport to distant markets until consumption maturity is reached.
本研究评估了一些酶促和非酶促抗氧化系统在冷藏（R）10至30天以及气调（CA）条件下15至50天期间，对哈斯牛油果早采和晚采的外果皮和中果皮以及货架期（SL）或食用成熟度时氧化应激的抵御能力。同时还评估了抗氧化系统与生理失调发生之间的可能关系。结果表明，酶促系统——超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）、苯丙氨酸解氨酶（PAL）和多酚氧化酶（PPO）——以及非酶促系统，如酚类化合物（PC），对储存和货架期产生的应激表现出不同的反应。总体而言，SOD、CAT、PAL和PPO在储存（R或CA）过程中没有显著变化。在食用成熟度时，中果皮（RSL和CASL）中的SOD、POD和PAL活性下降，而在CASL15 - 50d时，外果皮中的CAT活性增加。相反，随着收获期的推进，外果皮中的PC含量下降，而中果皮中的PC含量增加。生理失调（黑斑）仅在冷藏条件下出现在R30d的外果皮上以及RSL30d的中果皮上，分别与低SOD、低SOD和POD活性值以及低PC含量（对香豆酸及其衍生物和咖啡酸衍生物）同时出现。这些结果支持将气调作为一种采后技术，通过在牛油果运输到遥远市场直至达到食用成熟度期间抗氧化防御的联合作用，来防止生理失调的发生。
