Ho Q Tri, Verlinden Bert E, Verboven Pieter, Vandewalle Stefan, Nicolaï Bart M
BIOSYST-MeBioS, Faculty of Bioscience Engineering, Katholieke Universiteit Leuven, Willem de Croylaan 42, B-3001 Leuven, Belgium.
J Exp Bot. 2006;57(15):4215-24. doi: 10.1093/jxb/erl198. Epub 2006 Nov 3.
Gas transport in fruit tissue is governed by both diffusion and permeation. The latter phenomenon is caused by overall pressure gradients which may develop due to the large difference in O(2) and CO(2) diffusivity during controlled atmosphere storage of the fruit. A measurement set-up for tissue permeation based on unsteady-state gas exchange was developed. The gas permeability of pear tissue was determined based on an analytical gas transport model. The overall gas transport in pear tissue samples was validated using a finite element model describing simultaneous O(2), CO(2), and N(2) gas transport, taking into account O(2) consumption and CO(2) production due to respiration. The results showed that the model described the experimentally determined permeability of N(2) very well. The average experimentally determined values for permeation of skin, cortex samples, and the vascular bundle samples were (2.17+/-1.71)x10(-19) m(2), (2.35+/-1.96)x10(-19) m(2), and (4.51+/-3.12)x10(-17) m(2), respectively. The permeation-diffusion-reaction model can be applied to study gas transport in intact pears in relation to product quality.
水果组织中的气体传输受扩散和渗透作用的共同影响。后一种现象是由整体压力梯度引起的，在水果的气调贮藏过程中，由于氧气和二氧化碳扩散率的巨大差异，可能会形成这种压力梯度。基于非稳态气体交换开发了一种用于组织渗透的测量装置。基于解析气体传输模型确定了梨组织的气体渗透率。使用有限元模型对梨组织样本中的整体气体传输进行了验证，该模型描述了氧气、二氧化碳和氮气的同时传输，并考虑了呼吸作用导致的氧气消耗和二氧化碳产生。结果表明，该模型很好地描述了实验测定的氮气渗透率。皮肤、皮层样本和维管束样本渗透的实验测定平均值分别为(2.17±1.71)×10⁻¹⁹ m²、(2.35±1.96)×10⁻¹⁹ m²和(4.51±3.12)×10⁻¹⁷ m²。渗透-扩散-反应模型可用于研究完整梨中的气体传输与产品质量的关系。
