Coffee wastes are underused materials, largely available in coffee producing regions, which can be used to obtain pectins for the development of films for packaging. Coffee residual water (CRW) provided a phenolic and protein rich-pectic fraction (CRWP), which has 49 % uronic acid. This pectic fraction was used for the development of films with chitosan (Chit). Additionally, pectins extracted from coffee pulp with acid, pectin (CAP), hot water-soluble pectic fraction (HWSP), and chelating agent-soluble pectic fraction (CSP), were used to develop pectin-chitosan films. Flow and viscoelastic properties of film forming solutions were assessed, showing better characteristics for the pectins from the pulp over those from the residual water. The different composition of the pectin fractions allowed to relate film properties with their structural features and Fourier transform infrared (FTIR) spectroscopy showed interactions between pectin and chitosan in the films. Results showed that CAP-Chit and CSP-Chit films were transparent, hydrophobic, and had the best mechanical properties. These results demonstrate that coffee residual wastes have the potential to provide pectins that can be used for the development of films.

中文翻译：

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咖啡废物中果胶的价值用于开发果胶壳聚糖薄膜

咖啡废料是未得到充分利用的材料，主要可在咖啡产区获得，可用于获取果胶，用于开发包装薄膜。咖啡残留水 (CRW) 提供了富含酚类和蛋白质的果胶部分 (CRWP)，其中含有 49% 的糖醛酸。该果胶级分用于开发含壳聚糖 (Chit) 的薄膜。此外，用酸从咖啡果肉中提取的果胶、果胶（CAP）、热水可溶性果胶组分（HWSP）和螯合剂可溶性果胶组分（CSP）被用来开发果胶-壳聚糖薄膜。对成膜溶液的流动和粘弹性进行了评估，结果表明，来自纸浆的果胶比来自残留水的果胶具有更好的特性。果胶组分的不同组成允许将薄膜特性与其结构特征联系起来，傅里叶变换红外（FTIR）光谱显示薄膜中果胶和壳聚糖之间的相互作用。结果表明，CAP-Chit和CSP-Chit薄膜透明、疏水，且具有最佳的机械性能。这些结果表明，咖啡残留废物有可能提供可用于薄膜开发的果胶。