Garna Haikel, Mabon Nicolas, Robert Christelle, Cornet Charlotte, Nott Katherine, Legros Hervé, Wathelet Bernard, Paquot Michel
Unité de Chimie Biologique Industrielle, Faculté Univ. des Sciences Agronomiques de Gembloux, Passage des Déportés, 2 -B-5030 Gembloux, Belgium.
J Food Sci. 2007 Jan;72(1):C001-9. doi: 10.1111/j.1750-3841.2006.00227.x.
A study of the influence of extraction conditions (pH: 1.5 to 2; temperature: 80 to 90 degrees C; extraction time: 1 to 3 h), on the yield and purity of apple pomace pectin without elimination of impurities by alcohol washing was carried out. The alcohol precipitate yields varied from 2.9% to 8.9% depending on the pH. At pH 1.5, these yields were higher than those obtained at pH 2 contrary to the galacturonic acid purity (%w/w). Compounds other than pectins were solubilized from the cell walls of apple pomace at pH 1.5, and they were precipitated with alcohol. The apple pectins obtained from the different extraction procedures were highly methylated (54.5% to 79.5%), especially when the conditions (temperature, pH) were drastic. Similar conclusions can be drawn for the neutral sugar content that decreased at pH 1.5 (arabinose, xylose, and galactose) or at the highest temperatures and extraction times (arabinose and galactose). The phenomenon of demethylation and pectin degradation of neutral sugars chains can be observed at acid pH, and for long extraction times. The presence of high quantities of mannose or fructose, glucose, and xylose in the alcohol precipitate showed that pectin precipitation with ethanol was not specific.
在不通过酒精洗涤去除杂质的情况下，开展了一项关于提取条件（pH值：1.5至2；温度：80至90摄氏度；提取时间：1至3小时）对苹果渣果胶产量和纯度影响的研究。酒精沉淀产量随pH值的变化在2.9%至8.9%之间。在pH值为1.5时，这些产量高于在pH值为2时获得的产量，这与半乳糖醛酸纯度（%w/w）情况相反。在pH值为1.5时，除果胶外的其他化合物从苹果渣细胞壁中溶解出来，并与酒精一起沉淀。从不同提取程序获得的苹果果胶高度甲基化（54.5%至79.5%），尤其是在条件（温度、pH值）剧烈的情况下。对于在pH值为1.5时（阿拉伯糖、木糖和半乳糖）或在最高温度和提取时间下（阿拉伯糖和半乳糖）降低的中性糖含量，也可得出类似结论。在酸性pH值和较长提取时间下，可观察到中性糖链的去甲基化和果胶降解现象。酒精沉淀物中存在大量甘露糖、果糖、葡萄糖和木糖，表明用乙醇沉淀果胶不具有特异性。
