Abstract Excess solar irradiation is responsible for commercially significant annual losses of apple fruit, and those losses are expected to increase in the majority of the world’s apple production regions. Losses are not limited to the orchard but are also represented by disorders that develop in the cold chain such as sunscald and elevated lenticel damage. Similarly, metabolism during storage would reflect changes and even diverge during ripening and cold storage depending upon relative amount of light exposure in the orchard. To determine and track these changes alongside changes of appearance, ‘September Wonder Fuji’, ‘Gala’, ‘Granny Smith’, and ‘Honeycrisp’ apples were selected from the periphery on the south-facing side of trees for contrasting sun exposure on opposite aspects, stored in 1 °C air, and peel from opposing sides sampled sequentially from 0 to 6 months. Additional sunburned peel was sampled at 0 and 6 months. Sun exposure provoked broad relative responses from multiple pathways indicative of solar stress response. Responses include accumulation of well-characterized photoprotective responses including accumulation of flavonol glycoside and carotenoid, compatible solutes, and primary metabolites. Others include previously unreported or lesser understood responses such as those potentially impacting membrane properties (including changes in levels of monogalactosyldiacyglycerides and stigmasteryl glycosides), epicuticular surface metabolites (including pentacyclic triterpenes and diacylglycerides), and production of volatile alkenals indicative of residual solar stress during storage. Taken together, metabolic evidence indicates orchard light environment continues to impact not only appearance, but also rate of ripening and potentially fruit quality, even on the same apple. In this way, light exposure of any given apple could influence every cold chain management decision, and sorting apples at-harvest according to cumulative light exposure would improve apple consistency while potentially avoiding losses due to peel disorders.

中文翻译：

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阳光与冷链的融合：阳光照射对苹果采后果皮代谢的影响

摘要 过量的太阳辐射是造成苹果果实每年重大商业损失的原因，预计世界上大多数苹果产区的损失会增加。损失不仅限于果园，还表现为冷链中出现的疾病，如日晒和皮孔损伤升高。同样，贮藏期间的代谢将反映成熟和冷藏期间的变化甚至发散，这取决于果园中光照的相对量。为了确定和跟踪这些变化以及外观的变化，从树木朝南侧的外围挑选了“九月奇迹富士”、“Gala”、“Granny Smith”和“Honeycrisp”苹果，以对比对面的阳光照射方面，储存在 1 °C 的空气中，并从 0 到 6 个月的时间顺序取样的对侧剥离。在第 0 个月和第 6 个月对额外晒伤的果皮取样。阳光照射引起了指示太阳应激反应的多种途径的广泛相对反应。反应包括充分表征的光保护反应的积累，包括黄酮醇糖苷和类胡萝卜素、相容溶质和初级代谢物的积累。其他包括以前未报告或不太了解的反应，例如那些可能影响膜特性的反应（包括单半乳糖甘油二酯和豆甾醇苷水平的变化）、表皮表面代谢物（包括五环三萜和甘油二酯），以及指示储存过程中残留太阳应力的挥发性烯烃的产生. 综合起来，代谢证据表明，果园光照环境不仅会继续影响外观，还会影响成熟速度和潜在的果实质量，即使在同一个苹果上也是如此。通过这种方式，任何给定苹果的光照都会影响每一个冷链管理决策，根据累积光照对收获时的苹果进行分类将提高苹果的一致性，同时可能避免因果皮紊乱造成的损失。