The consumption of loquat fruits is highly appreciated for their carotenoid content and valuable sensory notes, but it is limited due to the low shelf-life. An on-line temperature controlled microwave system based on infrared thermography was used to dry three different loquat cultivar at 60 °C. The time to reach the target value of 23% moisture content was about 105 min in Claudia fruits and 162 min in Virticchiara and Peluche. Seven carotenoids were identified in loquat fruits, among these the major were all-trans-β-carotene in Virticchiara and Claudia. Virticchiara had the major total carotenoid content (206 μg/g dry basis), followed by Peluche (158 μg/g d.b.) and Claudia (41 μg/g d.b.). The loss of carotenoids after drying ranged between 24% (Peluche) and 41% (Claudia). Carotenoids that showed a higher loss were on average: lutein (70%) and zeaxhantin (51%). Thirty-five volatile compounds were identified in fresh and dried loquats: the aldehydes were the most abundant class. After drying, aldehydes declined slightly, with alcohols falling more sharply. The shortened times by using temperature-controlled microwave heating with infrared thermography have guaranteed a fair quality of the dried loquats from the nutritional and sensory point of view, variable among the three cultivars.

中文翻译：

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三种不同枇杷品种 (Eriobotrya japonica Lindl.) 微波干燥果实中类胡萝卜素、感官特征和挥发性化合物的演变

枇杷果实因其类胡萝卜素含量和有价值的感官特征而受到高度赞赏，但由于保质期短，因此受到限制。使用基于红外热像仪的在线温控微波系统在 60 °C 下干燥三个不同的枇杷品种。在 Claudia 果实中达到 23% 水分含量目标值的时间约为 105 分钟，在 Virticchiara 和 Peluche 中为 162 分钟。在枇杷果实中鉴定出7种类胡萝卜素，其中主要是Virticchiara和Claudia中的全反式β-胡萝卜素。Virticchiara 的总类胡萝卜素含量最高（206 μg/g 干基），其次是 Peluche（158 μg/g db）和 Claudia（41 μg/g db）。干燥后类胡萝卜素的损失范围在 24% (Peluche) 和 41% (Claudia) 之间。平均而言，损失较高的类胡萝卜素：叶黄素 (70%) 和玉米黄质 (51%)。在新鲜和干燥的枇杷中鉴定出 35 种挥发性化合物：醛类含量最高。干燥后，醛类略有下降，醇类下降幅度更大。使用带红外热像仪的温控微波加热缩短了时间，从营养和感官的角度来看，保证了干燥枇杷的公平质量，这三个品种之间存在差异。