Active packaging based on wheat germ protein isolate–Malva sylvestris leaf mucilage embedded with D-limonene nanoliposome: preparation and characterization

Abstract

Abstract Background The aim of this study is to prepare wheat germ protein/Malva sylvestris leaf mucilage (WGPI/MSLM) biocomposite layers embedded with D-limonene nanoliposomes (NLP). The effects of WGPI/MSLM ratio (0.4–2.5), NLP (0–3%), and glycerol content (35–50%, w/w based on WGPI weight) on water vapor permeability (WVP), thickness, antioxidant activity, mechanical properties, and solubility of the fabricated bio-nanocomposites were investigated through faced-centered central composite design. Results Our results showed the effects of WGPI/MSLM ratio, glycerol content, and liposome content as well as the interaction between the ratio and NLP content on WVP was significant. The sample with 3% NLP and 35% glycerol and a ratio of 0.4 WGPI/MSLM had the lowest solubility. As the ratio of WGPI/MSLM increased, the value of tensile strength (TS) of the samples increased. The lowest elongation at break (26.21%) exhibited by film with 2.5 WGPI/MSLM, 35% glycerol, and no NLP. The highest antioxidant activity (58.6%) was observed in formulated films with 3% NLP, and a WGPI/MSLM ratio of 0.4. The optimal active film was obtained at a ratio of 0.4 WGPI/MSLM, 35% glycerol, and 3% NLP. The analysis confirmed the antibacterial activity of the optimal films against Escherichia coli and Staphylococcus aureus, as well as the larger contact angle of the optimal film compared to the control film and the greater roughness of the optimal film compared to the control sample. Conclusions In conclusion, this study successfully produced active films of wheat germ protein/Malva sylvestris leaf mucilage embedded with D-Limonene nanoliposomes. The optimal active film exhibited low solubility, high tensile strength, high antioxidant activity, and antibacterial activity against Escherichia coli and Staphylococcus aureus. Graphical Abstract