Structural, antioxidant, prebiotic and anti-inflammatory properties of pectic oligosaccharides hydrolyzed from okra pectin by Fenton reaction
Structural, antioxidant, prebiotic and anti-inflammatory properties of pectic oligosaccharides hydrolyzed from okra pectin by Fenton reaction
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DOI：
10.1016/j.foodhyd.2021.106779
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发表时间：
2021-04-13
影响因子：
10.7
通讯作者：
Chang, Yoon Hyuk
中科院分区：
文献类型：
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作者：
Yeung, Yuen Kwan;Kang, Yu-Ra;Chang, Yoon Hyuk
为了阐明果胶低聚糖（POS）的生产具有良好的抗氧化剂，益生元和抗炎活性的最佳条件下，黄秋葵果胶（OP）的水解芬顿反应与不同浓度（3 mM，5 mM和7 mM）的硫酸亚铁。OP的分子量为112.31 kDa。在与3 mM、5 mM和7 mM FeSO 4（产物分别命名为POS 3、POS 5和POS 7）进行芬顿反应后，分子量分别显著降低至6.09 kDa、4.89 kDa和1.79 kDa。这表明，芬顿反应是一种有效的方法来水解果胶，以获得POS。芬顿反应产生的OH攻击鼠李糖半乳糖醛酸-I的同型半乳糖醛酸区域和中性侧链。由于相对分子质量较低，POS的抗氧化活性（DPPH和ABTS自由基清除活性）高于OP。POS还增加了益生菌（鼠李糖乳杆菌ATCC 7469和长双歧杆菌ATCC 15707）的数量，并促进SCFA的产生。此外，低分子量的POS抑制LPS诱导的亚硝酸盐和炎性细胞因子（包括白细胞介素（IL）-1？和IL-6）以及诱导型一氧化氮合酶（iNOS）/核因子（NF）-？RAW 264.7细胞中的B信号轴。因此，芬顿反应可以成功制备出比OP具有更好生物活性的POS。在所制备的3种POS中，POS 7具有最高的抗氧化和抗炎活性以及良好的益生能力。
To elucidate optimum conditions for the production of pectic oligosaccharides (POSs) with excellent antioxidant, prebiotic, and anti-inflammatory activities, okra pectin (OP) was hydrolyzed by Fenton reaction with different concentrations (3 mM, 5 mM, and 7 mM) of FeSO4. Molecular weight of OP was 112.31 kDa. After Fenton reaction with 3 mM, 5 mM, and 7 mM of FeSO4 (products were named as POS3, POS5, and POS7, respectively), molecular weights were significantly reduced to 6.09 kDa, 4.89 kDa, and 1.79 kDa, respectively. This indicates that Fenton reaction is an efficient way to hydrolyze pectin to obtain POSs. Regarding monosaccharide compositions, FT-IR spectra, and NMR spectra ascertained that ?OH produced by Fenton reaction attacked the homogalacturonan region and neutral side chains of rhamnogalacturonan-I. POSs had higher antioxidant activities (DPPH and ABTS radical scavenging activities) than OP due to their lower molecular weights. POSs also increased the number of probiotics (Lactobacillus rhamnosus ATCC 7469 and Bifidobacterium longum ATCC 15707) and promoted generation of SCFAs. Furthermore, POSs with lower molecular weights inhibited LPS-induced nitrite and inflammatory cytokines (including interleukin (IL)-1? and IL-6) as well as inducible nitric oxide synthase (iNOS)/nuclear factor (NF)-?B signaling axis in RAW 264.7 cells. Therefore, it can be concluded that Fenton reaction can successfully prepare POSs having better biological activities than OP. Among three POSs produced, POS7 had the highest antioxidant and anti-inflammatory activities and good prebiotic capacity.