不同回温温度的间歇热处理对‘塔罗科’血橙的保鲜效果

Quality Preservation of ‘Tarocco' Oranges by Intermittent Heat Treatment with Different Return Temperatures

以‘塔罗科’血橙为试材,采用56℃的热水,分别对血橙每连续处理40 s后放入不同温度（0、5、20℃）的水中进行回温间歇热处理,其总有效的热处理时间为2 min,研究其在贮藏（2℃、相对湿度（relative humidity,RH）90%-95%条件下21 d）、模拟运输（10℃、RH 60%-70%条件下7 d）和货架（20℃、RH 60%-70%条件下7 d）3个物流变温阶段的保鲜效果。结果表明,不同温度的回温间歇热处理组可以降低血橙的腐烂率,其中,5℃的回温间歇热处理组腐烂率最低;在货架期末期,5℃的回温间歇热处理可提高血橙表皮中的多酚氧化酶、过氧化物酶、超氧化物歧化酶、过氧化氢酶的活性,同时,也能够保持很好的色泽（柑橘色泽指数、色相）、硬度和营养品质（花色苷、总酸、可溶性固形物含量）。此外,0℃的回温间歇热处理使血橙温差变化最大,5℃次之,20℃最小,适宜的温差变化可以促进‘塔罗科’血橙的保鲜效果。

In this study, the effect of intermittent hot water（56 ℃） immersion for 2 min with temperature return in cold or warm water（0, 5 and 20 ℃） after every 40 s continuous treatment on quality preservation of ‘Tarocco＇ orange during three sequential stages of logistics, namely cold quarantine（at 2 ℃, relative humidity（RH） 90%-95% for 21 days）, simulated transport（at 10 ℃, RH 60%-70% for 7 days） and shelf life（at 20 ℃, RH 60%-70% for 7 days）. The results showed that the intermittent heat treatments with different return temperatures could reduce the decay index of ‘Tarocco＇ orange and 5 ℃ return temperature treatment had the least decay index among them. At the same time, this treatment could enhance the activities of polyphenol oxidase（PPO）, peroxidase（POD）, superoxide dismutase（SOD）, and cactalase（CAT） in fruit peel towards the shelf life, and maintain color parameters（color index and Hue）, firmness and nutritional attributes（the contents of anthocyanins, total acid and soluble solids）. Furthermore, 0 ℃ return temperature treatment induced maximum temperature difference, followed by 5 ℃ return temperature treatment, and minimum temperature difference was obtained by returning the temperature to 20 ℃. Conclusively, the suitable temperature variation promotes the quality preservation of ‘Tarocco＇ oranges.