Abstract Pome fruit stored under a controlled atmosphere (CA) often suffers hypoxia due to the mismatch of O2 level in the storage rooms and the fruit’s O2 consumption. Fruit response-based O2 sensing and control could be an efficient approach to reduce the hypoxia-related physiological disorders and therefore increase the shelf life of stored fruit. This research aims to validate and evaluate the application of nondestructive gas in scattering media absorption spectroscopy (GASMAS) O2 sensing in fruit post-harvest. In the first stage, the GASMAS O2 sensor was validated on a fruit mimicking multilayer model system where a high correlation was observed between the measured and reference O2 partial pressures (r2 ≥ 0.9). Later, the GASMAS sensor was evaluated on two apple cultivars (Malus x domestica ‘Golden delicious’, Malus x domestica ‘Nicoter’) and one pear cultivar (Pyrus communis ‘Conference’). The observed GASMAS signal from the ‘Golden delicious’ apples were nearly 2 times higher than the signal from ‘Nicoter’ apples and 5 times higher than from the ‘Conference’ pears. In the next stage, GASMAS measurements were taken on water submerged ‘Golden delicious’ apple and ‘Conference’ pear to investigate the difference in O2 consumption in those fruit. The calculated relative O2 changes during respiration and evolution of the O2 partial pressure after nitrogen treatment for both the fruit were found different. It was hypothesized that these findings may be attributed to variations in fruit porosity. And finally, the influence of skin and additional surface coating on the gas exchange was studied by immersing unpeeled, peeled and coated samples in the gaseous nitrogen for 2 h before measurement. The coating was found to reduce the gas exchange compared to the unpeeled samples which already exhibited a lower exchange rate than the peeled samples.

中文翻译：

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使用非破坏性气体在散射介质吸收光谱中探索梨果中的氧扩散和呼吸

摘要 在可控气氛下贮藏的梨果果实，由于贮藏室中的氧气含量与果实的氧气消耗量不匹配，经常会出现缺氧现象。基于水果响应的 O2 传感和控制可能是减少缺氧相关生理障碍的有效方法，从而延长储存水果的保质期。本研究旨在验证和评估无损气体在果实采后散射介质吸收光谱 (GASMAS) 氧气传感中的应用。在第一阶段，GASMAS O2 传感器在模拟水果的多层模型系统上进行了验证，其中观察到测量的 O2 分压和参考 O2 分压 (r2 ≥ 0.9) 之间存在高度相关性。后来，GASMAS 传感器在两个苹果品种（Malus xdomestica 'Golden beautiful'，Malus xdomestica 'Nicoter') 和一个梨品种 (Pyrus community 'Conference')。观察到的来自“黄金美味”苹果的 GASMAS 信号比来自“尼古特”苹果的信号高近 2 倍，比来自“会议”梨的信号高 5 倍。在下一阶段，对浸水的“黄金美味”苹果和“会议”梨进行了 GSMAS 测量，以研究这些水果中 O2 消耗量的差异。发现两种水果在呼吸过程中计算的相对 O2 变化和氮处理后 O2 分压的演变是不同的。据推测，这些发现可能归因于果实孔隙度的变化。最后，通过浸没去皮，研究了皮肤和附加表面涂层对气体交换的影响，在测量前将样品在气态氮中剥离和涂覆 2 小时。发现与未剥皮样品相比，涂层减少了气体交换，未剥皮样品已经表现出比剥皮样品低的交换率。