大豆多糖固体碱催化剂脱酯效果影响因素  

Factors Influencing De-Esterification of Soluble Soybean Polysaccharide with Solid Base Catalyst

作　　者：刘少聪 何志勇[1] 曾茂茂[1] 王召君 陈洁[1] LIU Shaocong;HE Zhiyong;ZENG Maomao;WANG Zhaojun;CHEN Jie(State Key Laboratory of Food Science and Technology,Jiangnan University,Wuxi 214122,China)

机构地区：[1]食品科学与技术国家重点实验室,江南大学,江苏无锡214122

出　　处：《食品与生物技术学报》2021年第1期82-90,共9页Journal of Food Science and Biotechnology

基　　金：天津市合成生物学创新能力提升计划项目(TSBICIP-KJGG-004)。

摘　　要：为了研究固体碱催化剂对大豆多糖(SSPS)脱酯效果的影响,以商业高甲氧基大豆多糖(SSPS)为原料,利用固体碱MgO为催化剂,制备低酯化度的SSPS。研究反应温度、时间和催化剂投料质量比对SSPS脱酯效果的影响。脱酯效果通过产物相对分子质量、酯化度(DE)以及产物单糖组成等指标检验。结果显示,随着反应温度升高,产物SSPS的相对分子质量不断降低,酯化度不断降低,多分散性(PDI)逐渐增加;催化剂投料质量比从1∶100增加到1∶5,酯化度显著下降,但产物SSPS的相对分子质量和多分散性变化相对比较小,而进一步增加催化剂的投料质量比,所有指标均变化很小;反应时间的延长,产物SSPS的甲酯化度不断下降,多分散性也不断增加,且越到反应后期,酯化度下降越慢。单糖组成结果表明,固体碱MgO催化SSPS脱甲酯过程,侧链上中性糖被脱除最快,主链断裂和脱酯几乎是同步的,但聚阿拉伯糖和聚半乳糖侧链本身降解要比主链降解缓慢。与碱法脱酯工艺相比,在达到相似的酯化度前提下,MgO固体碱催化脱酯工艺产物具有更高的相对分子质量、更低的多分散性以及更好的产物颜色。上述结果说明MgO脱酯工艺在未来SSPS脱酯实际生产中可能有着良好应用前景。The effect of solid bases on de-esterification of soluble soybean polysaccharides(SSPS)was investigated in this paper.A commercial high-methoxy soybean polysaccharide(SSPS)was used as the raw material,and a solid base MgO was used as the catalyst.The effects of reaction temperature,reaction time and catalyst feed ratio on the de-esterification of SSPS were investigated.The de-esterification effects were estimated by the molecular weight,the degree of esterification(DE),and the monosaccharide composition.The results showed that the molecular weight and DE of product decreasedas the reaction temperature increased,while the polydispersity(PDI)gradually increased.When the catalyst amount increased from 1∶100 to 1∶5,DE decreased significantly.However,the changes in the molecular weight and PDI of the product were relatively small.If further increasing the catalyst feed ratio,all indicators changed insignificantly.As the reaction time prolonged,DE of the product further declined and PDI further increased.The degree of esterification decreased more slowly at the laterreaction stage.The results of monosaccharide composition showed that the neutral sugars in side chains were removed most quickly,while the main chain breaks and de-esterification were almost synchronous.Degradation of polyarabinose and polygalactose side chains was slower than that of the main chain.Compared with the bases de-esterification process,the MgO de-esterification process achieved products with higher molecular weight,lower PDI,and better product color if with a similar degree of esterification.The above results indicated that the MgO de-esterification process would have a good application prospect in future SSPS de-esterification.

关 键 词：大豆多糖 碱性催化剂 脱甲酯 酯化度 相对分子质量 

分 类 号：TS202.3[轻工技术与工程—食品科学]