食品科学 ›› 2022, Vol. 43 ›› Issue (16): 1-8.doi: 10.7506/spkx1002-6630-20210717-200

• 食品化学 •    下一篇

魔芋葡甘聚糖/表面脱乙酰甲壳素纳米纤维复合凝胶的制备及流变性能

姜海鑫,黄叶群,郑萍云,赵建波,段孟霞,庞杰,吴春华   

  1. (福建农林大学食品科学学院,福建 福州 350002)
  • 出版日期:2022-08-25 发布日期:2022-08-31
  • 基金资助:
    国家自然科学基金青年科学基金项目(31801616);福建农林大学优秀硕士论文基金项目(1122YS01008); 福建农林大学杰出青年科研人才计划项目(xjq201912)

Preparation and Rheological Properties of Konjac Glucomannan/Surface Deacetylated Chitin Nanofiber Composite Gels

JIANG Haixin, HUANG Yequn, ZHENG Pingyun, ZHAO Jianbo, DUAN Mengxia, PANG Jie, WU Chunhua   

  1. (College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China)
  • Online:2022-08-25 Published:2022-08-31

摘要: 研究魔芋葡甘聚糖(konjac glucomannan,KGM)与不同质量分数的表面脱乙酰甲壳素纳米纤维(surface deacetylated chitin nanofiber,S-ChNF)制成的复合凝胶的微观结构及性能变化。结果表明,KGM/S-ChNF复合凝胶均呈现剪切稀化现象,符合幂定律模型,是一种假塑性流体;且随着S-ChNF添加量的增加,凝胶的黏度增加,剪切应力降低,稠度系数由23.174 Pa·sn增大至29.950 Pa·sn,而流动指数则由0.436 63降低至0.413 08,表明其假塑性能提高。动态黏弹性分析表明,储能模量和损耗模量均表现出对角频率的依赖性,且随着S-ChNF添加量的增加,两者呈现上升趋势。此外,交叉点由6.77 s-1向低角频率方向移动至3.77 s-1,表明分子间氢键作用力增强,增大了KGM分子链移动的阻力,松弛时间变长,凝胶倾向于呈现弹性特征。傅里叶变换红外光谱、扫描电子显微镜及热重分析结果显示,随着S-ChNF含量的增加复合体系内分子间相互作用增强,形成具有稳定网络结构的体系,从而改善复合凝胶的流变性特并且提高了复合凝胶的热稳定性。

关键词: 表面脱乙酰甲壳素纳米纤维;魔芋葡甘聚糖;甲壳素;流变特性;复合凝胶

Abstract: The microstructure and properties of composite gels prepared from konjac glucomannan (KGM) and surface deacetylated chitin nanofibers (S-ChNF) at different concentrations were studied. The results showed that the KGM/S-ChNF composite gel was a pseudoplastic fluid with shear thinning nature, which conformed to the power law model. With increasing S-ChNF concentration, the gel’s viscosity increased, its shear stress decreased, its viscosity coefficient increased from 23.174 Pa·sn to 29.950 Pa·sn, and its flow index decreased from 0.436 63 to 0.413 08, indicating enhanced pseudoplasticity. Dynamic viscoelastic analysis showed that both the storage and loss moduli were dependent on angular frequency, and displayed an increasing trend with increasing S-ChNF concentration. In addition, the crossing point moved from 6.77 s-1 to 3.77 s-1, indicating that the intermolecular hydrogen bonding was enhanced, increasing the resistance to KGM molecular chain movement and prolonging the relaxation time. Consequently, the gel tended to be an elastic fluid. The results of Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and thermogravimetric analysis showed that increasing S-ChNF content could enhance the intermolecular interaction in the composite system, leading to the formation of a stable network structure, thus improving the rheological properties and enhancing the thermal stability of the composite gel.

Key words: surface deacetylated chitin nanofibers; konjac glucomannan; chitin; rheological properties; composite gels

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