Functional properties of various molecular weights and functional groups on pectin

19922.1财政年度取得了以下成果。制备了不同相对分子质量和官能团的果胶。以市售高甲氧基果胶和新鲜水果为原料，采用酸脱甲基法制备果胶。我们分析了化学成分，并用凝胶渗透色谱(GPC)测量了分子分布(取决于科研经费)。结果表明，随着脱甲基化时间的延长，甲氧基减少，分子量分布向低分子量侧移动。考察了阳离子对Sol-Gel转变过程的流变性和粘度行为的影响。加入少量Ca~(2+)和~(2+)后，脱甲基果胶形成的凝胶比较均匀，而与Mg~(2+)和~(gt；)形成凝胶时，由于分子的捕获作用，凝胶形成的凝胶行为不均匀。采用差示扫描量热法(DSC)研究了阳离子对各种低甲氧基果胶溶液热性能的影响。结果表明，甲氧基含量的不同对凝胶的冻结峰温、熔融峰温和热焓有影响。阐明了不同相对分子质量的果胶和不同官能团的果胶在果胶的溶胶-凝胶转变过程中起着重要作用。无花果多糖的功能性质研究。(1)影响无花果水提物凝胶化行为的因素。(2)无花果多糖水溶液和凝胶的流变性研究。(3)对无花果果冻的质构特征进行了研究。我们想要考察水在溶胶-凝胶中的行为以及各种添加剂对阳离子的影响，并在未来阐明不同分子质量的果胶和官能团的功能性质。

The following results were obtained in the fiscal year1992.1. Prepared various molecular weights and functional groups of pectin. Each pectin was prepared from commercially high methoxyl pectin and fresh fruits by the acid-demethylating method. We analyzed the chemical composition, and measured the molecular distribution (dependent on the science research budget) by GPC. Then we clarified that the methoxyl groups decreased with an increase in demethylating time, and the molecular weight distribution shifted to the lower molecular weight side.2. The effect of cations on the rheological properties of the sol-gel transition process and the viscosity behavior were examined. A gel formation with demethylated pectin was appeared uniform with a slight addition of Ca^<2+,> but the behavior was not uniform when making gel with Mg^<2+> because catch of the molecules rapidly combined.3. The effect of cations on the thermal properties of various low methoxyl pectin solutions were measured by DSC. It was determined that the difference in the content of the methoxyl groups has an effect on the freezing peak temperature, the melting peak temperature and the enthalpy of gels. It was clarified that the pectins of different molecular weights and the functional groups were important in the sol-gel transition of the pectins.4. Functional propertics of polysaccharide of jelly fig. (1) Factors affecting the gelation behavior of aqueous components extracted from jelly fig. (2) Rheological properties of aqueous polysaccharide sols and gels prepared from jelly fig. (3) The texture profiles of jelly fig were examined. We want to examine the behavior of water in the sol-gel and the influence of various additions on the cations as well as clarify the functional properties of the pectins of different molecular weights and the functional groups in the future.