柚果皮渣富含果胶，为了实现柚果不同部位果胶的个性化应用和柚果加工副产物的资源化利用，该文使用酸法提取柚果果皮和囊衣果胶，以商品柑橘果胶为对照，利用高效液相色谱（High-performance liquid chromatography, HPLC）、傅里叶变换红外色谱（Fourier transform infrared spectroscopy, FTIR）、流变仪对其理化特性、分子结构和流变学性质进行了研究。结果表明，囊衣果胶和柚皮果胶的半乳糖醛酸含量分别为75.13 wt.%和87.33 wt.%，酯化度分别为65.69%和64.04%，均为高酯果胶。囊衣果胶的峰位分子量为2.02×105 Da，显著大于柑橘果胶和柚皮果胶。囊衣果胶和柚皮果胶的单糖组成主要包括半乳糖醛酸、鼠李糖、阿拉伯糖和半乳糖等。柚皮果胶和囊衣果胶的流变特性指数分别为0.508和0.635，均小于1，为剪切变稀的假塑性流体。与商品柑橘果胶和柚皮果胶相比，囊衣果胶的表观黏度、储能模量和损耗模量均较高，说明囊衣果胶具有较好的增稠性质和凝胶性。该研究结果为阐明柚果不同部位果胶的结构性质和柚果果胶资源的开发利用提供了理论依据。

Pomelo peels are abundant in pectin. This study investigated molecular structure and rheological properties of pectin extracted from various parts of the pomelo fruit using high-performance liquid chromatography (HPLC), fourier transform infrared spectroscopy (FTIR), and rheometry to facilitate personalized applications and resource utilization of pomelo byproducts. Results showed that the galacturonic acid content of pectin from pomelo endocarp and peel was 75.13% and 87.33%, respectively, while degree of esterification was 65.69% and 64.04%, respectively. Both endocarp and peel pectin were classified as high methoxyl pectin. The endocarp pectin exhibited the highest peak molecular weight (2.02×105 Da) when compared to citrus and peel pectin. The main neutral sugars present in endocarp and peel pectin comprised GalA, rhamnose, arabinose, and galactose. Pectins from endocarp and peel had flow behavior indices of 0.508 and 0.635, respectively, both lower than 1, indicating that they belonged to pseudoplastic fluids with shear-thinning behavior. The pectin from pomelo endocarp showed higher apparent viscosity, storage and loss modulus compared to other pectins, suggesting better thickening and gelling properties compared to both pomelo peel and commercial citrus pectin. This research may establish a theoretical foundation for the exploitation and utilization of pomelo peel resources.

国家自然科学基金(32101971)；现代农业产业技术体系建设专项资金项目(CARS-23)；北京市农林科学院科技创新能力建设专项(KJCX20220417,KJCX20240402)