Silkworm pupae protein-based film incorporated with Catharanthus roseus leaf extract-based nanoparticles enhanced the lipid stability and microbial quality of cheddar cheese

Abstract

The study aimed to develop a silkworm pupae protein-based film for enhancing the lipid oxidative and microbial stability of cheddar cheese. The bioactive properties were imparted to the silkworm pupae protein-based film using an optimum level (2.0%) of Catharanthus roseus leaf extract-based nanoparticles (Cat-Ros-NPs) synthesised following a green method. The cheese samples were packaged within the treated film (T₂, containing 2.0% Cat-Ros-NPs) and compared with control samples [control (cheese samples without any film), T₀ (cheese samples within the films without any bioactive agent) and T₁ {cheese samples within the films containing 2.0% C. roseus leaf extract (Cat-Ros-Ext)}] during 90 days trial (4±1 °C). The addition of bioactive agents (Cat-Ros-Ext or Cat-Ros-NPs) increased the thickness (µm) as well as density (g/ml) of the film, thereby decreasing the transmittance (%), solubility (%), moisture content (%), and water-vapour transmission rate (mg/mt²). Both the bioactive agents increased the redness (a*) and yellowness (b*) whereas decreased the brightness (L*) of the film. The films enhanced the antioxidant and antimicrobial properties of the enclosed cheese samples during storage and the highest values were recorded for the samples packed within T₂ films. The cheese samples packaged within T₂ and T₁ films showed significantly lower values for lipid oxidation and microbial counts. This positive effect of the films (T₂ and T₁) was also recorded on protein oxidation (total-carbonyl content) after day 30 and sensory quality after day 60. Our results indicate the successful use of silkworm pupae protein for the development of bioactive packaging for cheddar cheese.