Mohammadalinejhad Samira, Almonaitytė Augustė, Jensen Ida-Johanne, Kurek Marcin, Lerfall Jørgen
Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, 7491 Trondheim, Norway.
Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, 7491 Trondheim, Norway.
Int J Biol Macromol. 2023 Aug 15;246:125684. doi: 10.1016/j.ijbiomac.2023.125684. Epub 2023 Jul 3.
Microencapsulation of purple corn anthocyanins was carried out via an electrostatic extruder using alginate as a wall material. The influence of alginate concentration (1-2 %), extract concentration (20-30 %), and extrusion voltage (3-5 kV) on encapsulation efficiency and mean particle size was evaluated using response surface methodology. Optimal conditions were obtained to produce two different extract-loaded microbeads. Microbeads with the highest encapsulation efficiency (EE) and minimum particle size were achieved at 1 % alginate, 20 % extract, and 5 kV extrusion voltage (EE = 70.26 %, EE = 91.59 %, particle size = 1.29 mm). In comparison, the microbeads with the efficient entrapment and maximum particle size were obtained at 1 % alginate, 26 % extract, and 3 kV (EE = 81.15 %, EE = 91.01 %, particle size = 1.87 mm). Brunauer-Emmett-Teller (BET) surface area, pore size, and pore volume decreased after the inclusion of extract, with the lowest values reported for the smallest microbeads containing the extract. Scanning electron microscopy confirmed the results obtained by BET method and demonstrated fewer cracks and lower shrinkage of encapsulated samples. Fourier-transform infrared results proved the presence of anthocyanins and further possible interactions between phenolics and alginate. Stability studies revealed the color maintenance of anthocyanins-loaded microbeads during 4 weeks of storage at 4 °C and 8 °C. Moreover, the small and large particles showed a 7.6 and 3.4-fold reduction in degradation rate at 4 °C compared to their unencapsulated counterparts. Anthocyanins-loaded alginate microbeads retained over 80 % of cyanidin-3-glucoside at 4 °C and 8 °C, suggesting a promising potential of optimized microbeads for intelligent packaging applications.
采用静电挤出机，以海藻酸钠为壁材对紫玉米花青素进行微胶囊化。利用响应面法评估海藻酸钠浓度（1%-2%）、提取物浓度（20%-30%）和挤出电压（3-5 kV）对包封效率和平均粒径的影响。获得了制备两种不同载提取物微珠的最佳条件。在海藻酸钠浓度为1%、提取物浓度为20%、挤出电压为5 kV时，微珠的包封效率最高（EE = 70.26%，EE = 91.59%），粒径最小（粒径 = 1.29 mm）。相比之下，在海藻酸钠浓度为1%、提取物浓度为26%、挤出电压为3 kV时，获得了包封效率高且粒径最大的微珠（EE = 81.15%，EE = 91.01%，粒径 = 1.87 mm）。加入提取物后，Brunauer-Emmett-Teller（BET）比表面积、孔径和孔体积减小，含提取物的最小微珠的这些值最低。扫描电子显微镜证实了BET法获得的结果，并表明包封样品的裂纹较少且收缩率较低。傅里叶变换红外结果证明了花青素的存在以及酚类物质与海藻酸钠之间进一步可能的相互作用。稳定性研究表明，载花青素微珠在4℃和8℃储存4周期间颜色保持稳定。此外，与未包封的对应物相比，小颗粒和大颗粒在4℃时的降解率分别降低了7.6倍和3.4倍。载花青素的海藻酸钠微珠在4℃和8℃下保留了超过80%的矢车菊素-3-葡萄糖苷，这表明优化后的微珠在智能包装应用方面具有广阔的潜力。
