QOPNA, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
Carbohydr Polym. 2013 Apr 15;94(1):626-33. doi: 10.1016/j.carbpol.2013.01.088. Epub 2013 Feb 4.
The spent coffee grounds (SCG) are a food industry by-product that can be used as a rich source of polysaccharides. In the present work, the feasibility of microwave superheated water extraction of polysaccharides from SCG was studied. Different ratios of mass of SCG to water, from 1:30 to 1:5 (g:mL) were used for a total volume of 80 mL. Although the amount of material extracted/batch (MAE1) increased with the increase of the concentration of the sample, the amount of polysaccharides achieved a maximum of 0.57 g/batch for 1:10. Glycosidic-linkage composition showed that all extraction conditions allowed to obtain mainly arabinogalactans. When the unextracted insoluble material was re-extracted under the same conditions (MAE2), a further extraction of polysaccharides was observed (0.34 g/batch for 1:10), mainly galactomannans. Also, a high amount of oligosaccharides, mainly derived from galactomannans, can be obtained in MAE2 (0.96 g/batch for 1:10). This technology allows to obtain galactomannans and arabinogalactans in proportions that are dependent on the operating conditions.
废咖啡渣（SCG）是一种食品工业副产物，可以用作多糖的丰富来源。在本工作中，研究了微波过热水从 SCG 中提取多糖的可行性。使用了不同质量比的 SCG 与水，从 1:30 到 1:5（g:mL），总体积为 80 mL。虽然每次提取的物料量（MAE1）随样品浓度的增加而增加，但多糖的量在 1:10 时达到最大值，为 0.57 g/批。糖苷键组成表明，所有提取条件均允许获得主要的阿拉伯半乳聚糖。当在相同条件下对未提取的不溶性物质进行再次提取（MAE2）时，观察到进一步的多糖提取（1:10 时为 0.34 g/批），主要为半乳甘露聚糖。此外，在 MAE2 中还可以获得大量的低聚糖，主要来源于半乳甘露聚糖（1:10 时为 0.96 g/批）。该技术可以获得依赖于操作条件的半乳甘露聚糖和阿拉伯半乳聚糖。
