无籽刺梨渣膳食纤维的羧甲基化改性及性质

苏靖程; 李晗; 范方宇

doi:10.13386/j.issn1002-0306.2021090305

无籽刺梨渣膳食纤维的羧甲基化改性及性质

Carboxymethylation Modification and Properties of Dietary Fiber from Rosa sterilis Pomace

摘要

摘要: 为探究羧甲基化改性对无籽刺梨渣膳食纤维性质的影响，本文采用羧甲基化法改性无籽刺梨渣可溶性膳食纤维（Rosa sterilis Soluble Dietary Fiber，RSDF）和不溶性膳食纤维（Rosa sterilis Insoluble Dietary Fiber，RIDF），对比分析了无籽刺梨渣膳食纤维改性前后以及羧甲基化总膳食纤维（Carboxymethylated Total Dietary Fiber，CTDF）不同混合比例的理化和功能性质。结果表明：改性后，羧甲基化可溶性膳食纤维（Carboxymethylation Soluble Dietary Fiber，CSDF）、羧甲基化不溶性膳食纤维（Carboxymethylation Insoluble Dietary Fiber，CIDF）膨胀力、持水力、持油力、吸湿性、阳离子交换力、亚硝酸盐吸附力和葡萄糖吸附力均显著增大（P<0.05），CSDF/CIDF混合比例1:3时取代度为0.53±0.02，综合理化、功能性质为最优混合比例。红外光谱分析可知CSDF、CIDF羧甲基化修饰成功；电镜扫描分析可知两种膳食纤维结构疏松、存在大量褶皱和片状物质，CSDF/CIDF混合比例1:3时孔洞和片状结构更多；差示扫描热分析可知改性后，CSDF、CIDF贮藏稳定性均提高，CSDF/CIDF混合比例1:3热熔解温度最高为145 ℃。综上，羧甲基改性后，无籽刺梨膳食纤维性能均优于改性前且综合各项性能后，CSDF/CIDF混合比例1:3为最佳混合比。

Abstract: In order to explore the effect of carboxymethylation on Rosa sterilis pomace dietary fiber, the soluble dietary fiber (RSDF) and insoluble dietary fiber (RIDF) of Rosa sterilis pomace were modified by carboxymethylation in this paper. And the physicochemical, functional properties of carboxymethylated total dietary fiber and after the carboxymethylation modification of Rosa sterilis pomace dietary fiber were compared and analyzed. The results showed that after modification, the swelling capacity, water holding capacity, oil holding capacity, moisture absorption, cation exchange capacity, nitrite adsorption capacity and glucose adsorption capacity of CSDF and CIDF increased significantly (P<0.05). When the degree of substitution was 0.53±0.02, the mixing ratio of CSDF/CIDF was 1:3. The optimum mixture ratio was obtained by combining physicochemical and functional properties. FTIR analysis showed that the carboxymethylation of CSDF and CIDF was successful. SEM analysis showed that CSDF and CIDF loose structures, there were more holes and flake structures when the CSDF/CIDF mixing ratio was 1:3. DSC analysis showed that the storage stability of CSDF and CIDF improved after modification. When the mixing ratio of CSDF/CIDF was 1:3, the maximum hot melting temperature was 145 ℃. In summary, after carboxymethylation, the properties of Rosa sterilis dietary fiber were better than before and after integrating various performances, the best CTDF mixing ratio was 1:3.