Effect of lysozyme infusion, high-intensity ultrasound and controlled thermal treatment on the physicochemical and functional characteristics of Chenopodium album protein isolate based active packaging film

The characteristic outcome of films developed from high-intensity ultrasound (HIUS) and controlled thermal treatments of album protein isolates incorporated with lysozyme at 50, 75 and 100 mg/g, protein basis has been investigation. Highest inhibitory zone of 38.46 mm against Staphylococcus spp. was displayed by HIUS treated album protein isolate film containing lysozyme at 100 mg/g concentration. Antioxidant activity, total phenolic content, tensile strength (7.93 MPa), elongation at break, crystallinity, thickness, a* and b* values of HIUS and heat-treated films containing lysozyme increased significantly whereas, decrease in L* values, solubility, water vapor permeability has been observed. Fourier transform infra-red spectroscopy and morphological analysis indicated high ingredient cross-sectional interactions with comparatively smoother and compact biofilms. Highest glass transition temperature of 46.60 °C was observed for HIUS treated films when lysozyme was added at 100 mg/g, wherein, all films showed three characteristic peaks at 2Ɵ of about 20° and two minor peaks at 2Ɵ of 31° and 42° with highest crystallinity of 21 %. In addition, chemometric techniques like principal component analysis and hierarchical cluster analysis showed high correlation and interdependency between various film parameters studied.