不同溶解性面包果果胶的理化、结构性质及抗氧化活性的比较

Physicochemical, Structural, and Antioxidant Properties of Breadfruit (Artocarpus altilis) Pectin with Different Solubility

摘要:

该研究以面包果为原料，提取了水溶性果胶（Water-soluble Pectin, WSP）、螯合剂可溶性果胶（Chelatesoluble Pectin, CSP）、碳酸钠可溶性果胶（Sodium Carbonate-soluble Pectin, SSP），分析并比较了三者的理化性质、结构特性和抗氧化活性。结果表明：WSP 具有高粘度（145.80 mPa•s）、高分子量（1 241.3 ku）和高酯化度（86.33%）的特点，CSP具有低粘度（17.88 mPa•s）、低分子量（218.6 ku）和低酯化度（45.73%）的特点，SSP具有提取率高（47.73%）、溶解性好（96.20%）、粘度低（4.63 mPa•s）和分子量低（186.3 ku）的特点。三种果胶都主要由鼠李糖、阿拉伯糖、半乳糖、葡萄糖、木糖、半乳糖醛酸组成，红外分析光谱和扫描电镜结果表明这三种果胶的结构存在显著差异。抗氧化结果表明，WSP、CSP和SSP对羟自由基、ABTS+自由基和DPPH自由基的清除能力随质量浓度增加而增强。其中SSP对自由基的清除能力最强，在质量浓度为0.5 mg/mL时，对ABTS+自由基的清除率达到了96.56%。综上所述，SSP果胶表现出较好的抗氧化活性是由其较小分子量、支链丰富、低粘度以及光滑表面导致的。

Abstract:

Water-soluble pectin (WSP), chelate-soluble pectin (CSP), and sodium carbonate-soluble pectin (SSP) were extracted from breadfruit and their physicochemical properties, structural characteristics, and antioxidant activities were analyzed and compared. The results showed that WSP was characterized by high viscosity (145.80 mPa•s), high molecular weight (1241.3 ku), and high degree of esterification (86.33%). CSP was characterized by low viscosity (17.88 mPa•s), low molecular weight (218.6 ku), and low degree of esterification (45.73%), while SSP was characterized by a high extraction rate (47.73%), good solubility (96.20%), low viscosity (4.63 mPa•s), and low molecular weight (186.3 ku). The main monosaccharide compositions of the three kinds of pectin were rhamnose, arabinose, galactose, glucose, xylose, and galacturonic acid. The results of Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) indicated significant differences among the three types of pectin. The antioxidant results showed that the scavenging ability of WSP, CSP, and SSP on hydroxyl free, ABTS+ free and DPPH free radicals increased with the increase in mass concentration of each pectin. SSP had the strongest radical scavenging activity, reaching a scavenging rate of 96.56% of ABTS radicals at a concentration of 0.5 mg/mL. In conclusion, SSP pectin exhibited good antioxidant activity due to its small molecular weight, rich branched chains, low viscosity, and smooth surface.