Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10 000 Zagreb, Croatia.
Forensic Science Centre "Ivan Vučetić" Zagreb; Forensic Science Office, University of Zagreb, Ilica 335, 10 000 Zagreb, Croatia.
Food Res Int. 2018 Sep;111:244-255. doi: 10.1016/j.foodres.2018.05.034. Epub 2018 May 19.
Alginate hydrogels are often used for immobilization of plant-derived bioactive compounds by fast and simple ionic gelation technique. However, the structure of alginate gel network is very porous and mostly result with high-diffusion rates of encapsulated compound, what limits its application as delivery vehicle. In order to prevent losses of bioactives and prepare efficient encapsulation systems, the aim of this study was to evaluate a potential of new natural fillers, cocoa powder (CP) and carob (C) for structuring alginate network aimed for encapsulation of aqueous dandelion (Taraxacum officinale L.) leaf extract using ionic gelation. Whey protein isolates served as a standard filler. The influence of different concentrations of gelling medium (2% and 3% calcium chloride) on encapsulation properties of alginate systems was also evaluated. Calcium concentration affected morphological properties (more acceptable when using 3% CaCl), while textural properties and encapsulation efficiency of polyphenols and retained antioxidant capacity were more influenced by selected delivery materials. Alginate-whey protein isolates beads were scored with the highest loading capacity of polyphenols (>93%), while newly formulated binary mixtures (alginate-cocoa powder and alginate-carob) also enabled highly efficient entrapment of polyphenols (>88%). The slowest release of polyphenols in simulated gastrointestinal fluids were obtained when alginate was combined with CP and C, where system alginate-cocoa powder prepared with lower concentration of calcium chloride (2% CaCl) enabled the most extended release of total polyphenols and hydroxycinnamic acids. Obtained results strongly justified implementation of new plant-derived functional fillers (cocoa powder and carob) for encapsulation purposes and opened new directions for designing of binary carrier's.
海藻酸盐水凝胶常用于通过快速简单的离子凝胶技术固定植物来源的生物活性化合物。然而，海藻酸盐凝胶网络的结构非常多孔，导致包封化合物的扩散速率很高，这限制了其作为递送载体的应用。为了防止生物活性物质的损失并制备有效的封装系统，本研究旨在评估新的天然填充剂可可粉（CP）和角豆（C）的潜力，以构建海藻酸盐网络，用于通过离子凝胶法封装蒲公英（Taraxacum officinale L.）叶提取物的水溶液。乳清蛋白分离物用作标准填充剂。还评估了不同浓度的凝胶介质（2％和 3％氯化钙）对海藻酸盐系统封装性能的影响。钙浓度影响形态特性（使用 3％CaCl 时更可接受），而质构特性和多酚的包封效率以及保留的抗氧化能力受所选输送材料的影响更大。海藻酸钠-乳清蛋白分离物珠的多酚负载能力最高（>93％），而新配方的二元混合物（海藻酸钠-可可粉和海藻酸钠-角豆）也能够高效包封多酚（>88％）。在模拟胃肠道液体中，当海藻酸盐与 CP 和 C 结合时，多酚的释放最慢，其中用较低浓度的氯化钙（2％CaCl）制备的海藻酸盐-可可粉系统能够使总多酚和羟基肉桂酸的释放时间最长。所得结果充分证明了新型植物衍生功能填充剂（可可粉和角豆）在封装中的应用，并为设计二元载体开辟了新的方向。
