Development of bionanocomposite packaging films based on lignin nanoencapsulated anthocyanins extracted from agro-waste for enhancing the post-harvest shelf life of tomatoes†

Abstract

Anthocyanin, a natural pigment from the flavonoid family, can be useful as a natural colorant in the packaging industry. Due to the sensitivity to light, pH and temperature of anthocyanin, its applications are restricted. In the present study, anthocyanins extracted from black wheat bran (WB), black plum (BP) and blueberry (BB) were nanoencapsulated using a natural biopolymer, lignin, to enhance stability and improve the biological properties of anthocyanins. The synthesized nanoparticles (A-LNPs) exhibited satisfactory encapsulation efficiency (92.32 to 72.26%), size (126.13 to 145.17 nm), PDI (0.140 to 0.172), and zeta potential (−36.27 to −34.10 mV), and potent antioxidant and antibacterial activity against Staphylococcus aureus. These novel A-LNPs were observed to be light stable during 28 days of storage at room temperature compared to purified anthocyanins. A-LNPs were further used as active ingredients to develop polyvinyl alcohol–polyethylene glycol (PVA–PEG)-based packaging films. These PVA–PEG-A-LNP films were observed to retain the quality parameters of tomatoes for at least 15 days of storage compared to tomatoes packed with PVA–PEG films and control samples. Such biocompatible packaging films can serve as alternative materials to conventional plastic.