UMR408 SQPOV «Sécurité et Qualité des Produits d'Origine Végétale», INRA, Avignon University, F-84000 Avignon, France.
UMR408 SQPOV «Sécurité et Qualité des Produits d'Origine Végétale», INRA, Avignon University, F-84000 Avignon, France.
Food Chem. 2019 Mar 1;275:754-762. doi: 10.1016/j.foodchem.2018.09.156. Epub 2018 Sep 25.
Procyanidins and cell walls were extracted from pear at ripe and overripe stages in order to investigate the impact of ripening stage on their association. Procyanidin composition and structure remained stable at the overripe stage. Mid Infrared Spectroscopy (MIR) discriminated cell wall-procyanidin complex from initial purified cell wall material (CWM). Interactions between procyanidins and CWM isolated from the whole flesh (FL), parenchyma cells (PC), stone cells (ST) and skin (SK) at ripe and overripe stage were characterized using UV-Vis spectrometry using Langmuir isotherm formulation and Isothermal Titration Microcalorimetry (ITC). The affinity between procyanidins and CWM decreased as follows: PC > FL > ST > SK. The proportion of bound procyanidins increased at the overripe stage for all CWM and the maximal saturation level was obtained for overripe FL and ST. ITC indicated that associations between pear cell walls and procyanidins involved hydrogen bonds and mainly hydrophobic interactions for overripe PC.
为了研究成熟阶段对其结合的影响，从成熟和过熟阶段的梨中提取原花青素和细胞壁。过熟阶段原花青素的组成和结构保持稳定。中红外光谱（MIR）将细胞壁-原花青素复合物与初始纯化的细胞壁材料（CWM）区分开来。使用 Langmuir 等温线公式和等温热滴定微量热法（ITC），用紫外可见光谱法表征了整个果肉（FL）、果肉细胞（PC）、石细胞（ST）和果皮（SK）中分离的原花青素和 CWM 之间在成熟和过熟阶段的相互作用。原花青素与 CWM 的亲和力依次降低：PC > FL > ST > SK。所有 CWM 的结合原花青素比例在过熟阶段增加，过熟 FL 和 ST 达到最大饱和水平。ITC 表明，梨细胞壁与原花青素之间的相互作用涉及氢键，主要是过熟 PC 的疏水相互作用。
