Sirisakulwat Suparat, Nagel Andreas, Sruamsiri Pittaya, Carle Reinhold, Neidhart Sybille
Institute of Food Science and Biotechnology, Chair of Plant Foodstuff Technology, Hohenheim University, Stuttgart, Germany.
J Agric Food Chem. 2008 Nov 26;56(22):10727-38. doi: 10.1021/jf802173c.
Pectins, recovered from the peels of four mango ( Mangifera indica L.) cultivars by mimicking industrial techniques, were evaluated in terms of yield, composition, macromolecular properties, and technofunctional quality. Freeze-dried peels of mature-green fruits, after major mesocarp softening, and at full ripeness were extracted using hot acid. The pectins were precipitated in propan-2-ol and their crude yields quantified as alcohol-insoluble substance. Like apple pomace, the dried peels provided hardly acetylated (DAc < 6.3%) rapid-set to ultrarapid-set high-methoxyl pectins at starch-adjusted yields of 11-21 g/100 g. However, despite similar high molecular weight fractions and galacturonic acid/rhamnose ratios, their average molecular weight was markedly reduced by a characteristic, almost monodisperse fraction of 16000-19000. Expanded galactans, indicated by galactose/rhamnose ratios of 15-24 mol/mol, probably represented arabinogalactan side-chain fragments withstanding hot-acid extraction at pH 1.5 and 2.0, as implied by arabinose/galactose ratios of 8-15 and 33-56 mol/100 mol, respectively. Limited galacturonic acid contents made the mango peel pectins less valuable than commercial apple pectins with regard to gelling capacity and thickening properties. Whereas starch and matrix glycan fragments almost completely degraded during ripening, depolymerization of pectins and galactans was insignificant. Technofunctional properties, modulated by extraction at different pH values, were ascribed to structural differences influencing macromolecular entanglements.
通过模拟工业技术从四个芒果（芒果属印度种）品种的果皮中回收果胶，并对其产量、成分、大分子特性和技术功能质量进行了评估。使用热酸提取成熟绿色果实、中果皮主要软化后以及完全成熟时的冻干果皮。果胶在丙醇中沉淀，其粗产量以醇不溶物定量。与苹果渣一样，干燥的果皮在淀粉调整产量为11 - 21 g/100 g时，提供几乎未乙酰化（脱乙酰度<6.3%）的快速凝固到超快速凝固的高甲氧基果胶。然而，尽管它们具有相似的高分子量组分和半乳糖醛酸/鼠李糖比率，但它们的平均分子量明显降低，由16000 - 19000的特征性、几乎单分散的组分导致。分别由半乳糖/鼠李糖比率为15 - 24 mol/mol表明的扩展半乳聚糖，可能代表在pH 1.5和2.0下经受热酸提取的阿拉伯半乳聚糖侧链片段，这分别由阿拉伯糖/半乳糖比率为8 - 15和33 - 56 mol/100 mol所暗示。有限的半乳糖醛酸含量使得芒果皮果胶在胶凝能力和增稠性能方面不如商业苹果果胶有价值。淀粉和基质聚糖片段在成熟过程中几乎完全降解，而果胶和半乳聚糖的解聚不明显。通过在不同pH值下提取调节的技术功能特性归因于影响大分子缠结的结构差异。
