Preparation and characterization of edible whey protein nanofibrils and efficacy studies on the quality and shelf‐life of chilled food products

Abstract

AbstractWhey is the by‐product of cheese making which can be manipulated into edible films and coatings, it relies on its high viscosity, high hydrophobicity, and antimicrobial and antioxidant activity. In the present study, titanium‐based whey protein nanoparticles (WPNFs/TNPs) and whey protein isolates (WPI) were prepared and edible coatings and films were developed and characterized. The antimicrobial activity against common foodborne pathogens (S. aureus, E. coli, S. typhi, A. niger, P. expansum, and P. variotii) were conducted followed by their efficacy on six different chilled products analyzed on beef, chicken meat, mutton and fish meat, cheddar cheese and mozeralla cheese were selected for efficacy studies. The Scanning Electron Microscopy (Socaciu, Fogarasi et al.) revealed long and linear fibrils of WPNFs and with the addition of TNPs, the fibrils became denser. Fibril emulsions were expected to be more stable because of their high viscosity. Both the WPNFs/TNPs and WPI were smooth and homogenous surfaces without cracks or pore. The WPNFs/TNPs showed various degrees of antimicrobial activities against all the microbial strains and with the addition of nanoparticles, their interaction increased which further enhanced the quality of the product. Each film and coating had clear zones against all the desired microbes. The inhibition zones of WPI/TNPs were smaller than those of WPNFs/TNPs films. The addition of TNPs into with the nanofibrils enhanced the activity of nanofibrils and also it showed better and larger inhibition zones. The DPPH Radical‐scavenging activity of WPNFs/TNPs‐based samples was greater than that of the WPI/TNPs based samples. The highest was observed against the fish and mutton samples, followed by chicken and beef. The WPNFs/TNPs edible coatings decreased the microbial growth throughout storage for serval weeks. Our results may provide a basic understanding of the use of whey protein as an alternative for food safety of chilled food products.