Abstract Controlled postharvest stresses were used to induce the synthesis of antioxidants in tomato fruit. In this study, a hot-water (HW) treatment of 52 °C for 5 min promoted higher total oxygen radical absorbance capacity (ORAC) compared to fruit immersed in 25 °C water for 5 min. Whereas, ethylene treatment at high temperature, particularly at 35 °C for 24, 48 or 72 h, induced higher content of total phenolics and ferric reducing ability of plasma (FRAP) than fruit treated with ethylene at 20 or 30 °C. In combination, there was synergy between the treatments, and this was most notable by the increase of total phenolics in HW-treated tomatoes exposed to ethylene at 35 °C for 24, 48 or 72 h. There was also a significant increase of total ORAC in HW-treated fruit exposed to ethylene at 30 °C for 72 h or 35 °C for 24, 48 or 72 h. This increase in antioxidant capacity was observed in the hydrophilic fraction of HW-treated fruit exposed to ethylene at 30 °C for 72 h or 35 °C for 24 or 48 h and in the lipophilic fraction of HW-treated tomatoes exposed to ethylene at 35 °C for 24, 48 or 72 h. Moreover, The HW-treatment especially maintained the level of total carotenoids and ascorbic acid when exposed to ethylene at 30 °C for 72 h or 35 °C for 48 or 72 h. Nevertheless, the high temperature ethylene treatment reduced the a* value of tomato peel regardless of the application of HW treatment. In conclusion, application of a HW treatment of 52 °C for 5 min followed by exposure to ethylene at 35 °C for 48 h was most effective in synergistically improving the antioxidant capacity and composition of tomatoes without severely impairing color development.

中文翻译：

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热水处理与高温乙烯处理协同促进成熟青番茄抗氧化作用

摘要 受控的采后胁迫被用来诱导番茄果实中抗氧化剂的合成。在这项研究中，与浸泡在 25°C 水中 5 分钟的水果相比，52°C 的热水 (HW) 处理 5 分钟促进了更高的总氧自由基吸收能力 (ORAC)。而乙烯在高温下处理，特别是在 35 °C 下处理 24、48 或 72 小时，比在 20 或 30 °C 下用乙烯处理的水果诱导更高的总酚含量和血浆铁还原能力（FRAP）。结合起来，处理之间存在协同作用，最显着的是在 35°C 下暴露于乙烯 24、48 或 72 小时的经过 HW 处理的西红柿中总酚类物质的增加。在 30 °C 下暴露于乙烯 72 小时或在 35 °C 下暴露 24、48 或 72 小时，经过 HW 处理的水果的总 ORAC 也显着增加。在 30 °C 下暴露于乙烯 72 小时或 35 °C 下 24 或 48 小时的 HW 处理的水果的亲水部分以及暴露于 35 °C 24、48 或 72 小时。此外，当在 30°C 下暴露于乙烯 72 小时或 35°C 下 48 或 72 小时时，HW 处理尤其能保持总类胡萝卜素和抗坏血酸的水平。然而，无论采用何种 HW 处理，高温乙烯处理都降低了番茄皮的 a* 值。总之，应用 52°C 5 分钟的 HW 处理，然后在 35°C 下暴露于乙烯 48 小时最有效地协同提高番茄的抗氧化能力和成分，而不会严重损害颜色的发展。