Longping Branch, College of Biology, Hunan University, Changsha, China.
Hunan Provincial Key Laboratory for Fruits and Vegetables Storage Processing and Quality Safety, Changsha, China.
J Food Sci. 2023 Dec;88(12):4879-4891. doi: 10.1111/1750-3841.16803. Epub 2023 Oct 25.
To investigate the influence of heat treatment (HT) on Satsuma mandarin fruit's postharvest quality and cuticle composition, we immersed the fruit for 3 min in hot water at 52°C and subsequently stored them at room temperature (25°C) for 28 days, and fruit quality parameters, such as good fruit rate, weight loss rate, firmness, total soluble solids, total titratable acidity, and ascorbic acid content, were monitored. Additionally, changes in the peel's cuticle composition were analyzed, and wax crystal morphologies on the fruit surface were examined using scanning electron microscopy (SEM). The findings revealed that appropriate HT effectively preserved fruit quality. The main compositions of wax and cutin on the fruit's surface remained consistent between the HT and the CK during storage. The total content of wax and cutin initially increased, peaking on the 14th day of storage, and then decreased, falling below the levels observed on day 0. Notably, the total amount of cutin in the HT group exceeded that of the control group. Specifically, ω-hydroxy fatty acids with mid-chain oxo groups and mid-oh-ω-hydroxy fatty acids constituted approximately 90% of the total cutin content. Moreover, the HT group exhibited higher (p < 0.05) total wax content in relation to the control. Fatty acids and alkanes were the predominant components, accounting for approximately 87.5% of the total wax. SEM analysis demonstrated that HT caused wax crystals to melt and redistribute, effectively filling wax gaps. It suggests that HT holds promising potential as a green, safe, and eco-friendly commercial treatment for preserving the postharvest quality of Satsuma mandarin. PRACTICAL APPLICATION: In this study, Satsuma citrus (Citrus unshiu) underwent heat treatment (HT) and was subsequently preserved at room temperature (25°C) for 28 days. The findings revealed that HT significantly improved fruit quality compared to the control group. These findings provide valuable insights into the advancement of eco-friendly and pollution-free citrus preservation methods, offering essential strategies and process parameters for their practical application.
为了研究热处理（HT）对温州蜜柑果实采后品质和角质层组成的影响，我们将果实浸泡在 52°C 的热水中 3 分钟，然后在室温（25°C）下储存 28 天，并监测果实品质参数，如好果率、失重率、硬度、总可溶性固形物、总可滴定酸度和抗坏血酸含量。此外，还分析了果皮角质层组成的变化，并使用扫描电子显微镜（SEM）观察了果实表面蜡晶的形态。结果表明，适当的 HT 能有效保持果实品质。在贮藏过程中，HT 和 CK 处理的果实表面蜡质和角质的主要成分保持一致。蜡质和角质的总含量最初增加，在贮藏第 14 天达到峰值，然后减少，低于第 0 天的水平。值得注意的是，HT 组的角质总含量超过了对照组。具体来说，含中链 oxo 基团的 ω-羟基脂肪酸和中-oh-ω-羟基脂肪酸约占角质总含量的 90%。此外，HT 组的总蜡含量高于对照组（p<0.05）。脂肪酸和烷烃是主要成分，约占总蜡的 87.5%。SEM 分析表明，HT 导致蜡晶融化和重新分布，有效地填补了蜡质间隙。这表明 HT 作为一种绿色、安全、环保的商业处理方法，具有保持温州蜜柑采后品质的潜力。实际应用：本研究对温州蜜柑进行了热处理（HT），然后在室温（25°C）下保存 28 天。结果表明，HT 显著提高了果实品质，优于对照组。这些发现为开发环保、无污染的柑橘保鲜方法提供了有价值的见解，为其实际应用提供了必要的策略和工艺参数。
