Encapsulation of ZnO nanoparticles in modified pectin-protein complexes for food fortification and their antibacterial characteristics

Zinc deficiency is linked to the occurrence of chronic illnesses, such as stunting, which is still at high rates, primarily in low-income countries, due to poor nutrition and lack of access to essential micronutrients. This study developed a cost-effective material to fulfill zinc requirements and address this issue through food fortification. Zinc oxide nanoparticles (ZnO-NP) are promising zinc sources to consume, but they need to be modified through encapsulation using the combination of pectin and yogurt-derived protein complexes to enhance their stability and bioavailability. The encapsulation layer also prevents the interaction between the good bacteria in yogurt, as the target product in food fortification, and the ZnO nanoparticles, so that the good bacteria in the yogurt remain alive with the addition of this additive. Interaction between pectin and protein forms a coating complex influenced by the heating treatment during encapsulation. The successful formation of the encapsulation complex in this study is confirmed through the infrared spectrum and antibacterial characteristics of the material. The absence of a Zn-O peak in the infrared spectrum validates the successful formation of the coating layer. Encapsulated ZnO-NP exhibits lower antibacterial activity compared to the unencapsulated ZnO-NP due to the circumvented interaction between ZnO-NP and bacterial cells.