Jung Jooyeoun, Cavender George, Simonsen John, Zhao Yanyun
J Agric Food Chem. 2015 Mar 25;63(11):3031-8. doi: 10.1021/acs.jafc.5b00616. Epub 2015 Mar 16.
This study investigated the mechanisms of anthocyanin pigment retention using Fe(3+)-anthocyanin complexation and cellulose nanofiber (CNF)/sodium alginate (SA) layer-by-layer (LBL) coatings on thermally processed blueberries in aqueous media. Anthocyanin pigments were polymerized through complexation with Fe(3+) but readily degraded by heat (93 °C for 7 min) in the aqueous media because of poor stability. CNF/SA LBL coating was successful to retain anthocyanin pigments in thermally processed blueberries. Fruits coated with CNF containing CaCl2 followed by treatment in a SA bath formed a second hydrogel layer onto the CNF layer (LBL coating system) through cross-linking between Ca(2+) and alginic acid. Methyl-cellulose-modified CNF improved the interactions between CNF, the fruit surface, and the SA layer. This study demonstrated that the CNF/SA LBL coating system was effective to retain anthocyanin pigments on thermally processed whole blueberries, whereas no combined benefit of complexation with coating was observed. Results explained the mechanisms of the new approaches for developing colorful and nutritionally enhanced anthocyanin-rich fruit products.
本研究利用铁（III）-花青素络合以及纤维素纳米纤维（CNF）/海藻酸钠（SA）层层（LBL）包覆技术，研究了水介质中热加工蓝莓的花青素色素保留机制。花青素色素通过与铁（III）络合而聚合，但由于稳定性差，在水介质中易受热（93°C，7分钟）降解。CNF/SA LBL包覆成功地保留了热加工蓝莓中的花青素色素。用含氯化钙的CNF包覆水果，然后在SA浴中处理，通过钙离子与海藻酸之间的交联，在CNF层上形成了第二层水凝胶层（LBL包覆体系）。甲基纤维素改性的CNF改善了CNF、水果表面和SA层之间的相互作用。本研究表明，CNF/SA LBL包覆体系能有效地保留热加工全蓝莓中的花青素色素，但未观察到络合与包覆的协同效益。结果解释了开发色泽鲜艳、营养增强的富含花青素水果产品新方法的作用机制。
