Litchi (Litchi chinensis Sonn.) fruit, with its bright red color and sweet and juicy aril, is an important fruit crop in Asia, Africa, Australia, and South America. A major cause of the postharvest loss of litchi fruit is browning and decay. Chlorophyll breakdown and flavonoid synthesis occur simultaneously during the maturation of this nonclimacteric fruit. However, once litchi fruit is harvested, pericarp desiccation and membrane breakdown occur, which leads to browning with the rate of browning and later microcracking paralleling water loss rate. In addition, chilling injury can contribute to and increase pericarp browning and membrane leakage. Polyphenol oxidase and peroxidase are possibly key enzymes in the early stages of browning. An increase in the leakage of the pericarp membrane also occurs that correlates with browning. Many chemical treatments have been evaluated to retard pericarp browning, such as melatonin, hot water, acidified calcium sulfate (ACS), adenosine triphosphate, and tea seed oil. During long distance transportation, chemical treatments that involve sulfur are used, including SO₂ fumigation, acid dip after SO₂ fumigation, SO₂ fumigation and sulfur sheet package, or SO₂ fumigation followed by controlled atmosphere (CA), if approved by the importing country. Other treatments that avoid the use of SO₂ include melatonin, ACS, and hot water brushing combined with an acid dip, CA, and modified atmosphere packaging. Anthracnose is a common disease that accelerates browning and decay. Penicillium species as a saprophyte is also common with fruit infection occurring in the field, during harvest, in the packhouse, cold rooms, and shipping containers. Sulfur sheet or CA is used to reduce fruit rot after SO₂ fumigation and Sportak (prochloraz) for the control of penicillium. However, a replacement for postharvest SO₂ use is still urgently needed.

中文翻译：

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荔枝采后生理及处理


荔枝（Litchi chinensis Sonn.）果实颜色鲜红，假种皮甜多汁，是亚洲、非洲、澳大利亚、南美洲的重要水果作物。荔枝果实采后损失的一个主要原因是褐变和腐烂。在这种非跃变型水果的成熟过程中，叶绿素分解和类黄酮合成同时发生。然而，荔枝果实一旦采收，就会发生果皮干燥和膜破裂，从而导致褐变，其褐变速度和随后的微裂速度与失水速度平行。此外，冷害会导致并增加果皮褐变和膜渗漏。多酚氧化酶和过氧化物酶可能是褐变早期阶段的关键酶。果皮膜渗漏也会增加，这与褐变有关。许多化学处理已被评估可延缓果皮褐变，例如褪黑激素、热水、酸化硫酸钙（ACS）、三磷酸腺苷和茶籽油。长途运输时，采用涉及硫的化学处理，包括SO ₂ 熏蒸、SO ₂ 熏蒸后酸浸、SO ₂ 熏蒸和硫磺片包装，或 SO ₂ 熏蒸，然后进行受控气氛 (CA)（如果进口国批准）。其他避免使用 SO ₂ 的治疗方法包括褪黑激素、ACS 和热水刷洗结合酸浸、CA 和气调包装。炭疽病是一种常见病害，会加速褐变和腐烂。青霉属腐生菌也常见于田间、收获期间、包装厂、冷藏室和运输集装箱中发生的水果感染。 硫磺片或 CA 用于减少 SO ₂ 熏蒸后的水果腐烂，Sportak（咪鲜胺）用于控制青霉菌。然而，仍然迫切需要替代采后 SO ₂ 使用。