Fabricating an antioxidant and bacteriostatic soy protein isolate film double-crosslinked via dialdehyde cellulose nanofibers and Tara tannins for beef tallow and cooked pork preservation.

Although Tara tannins (TT) have given soy protein isolate (SPI) film antioxidant properties, the mechanical and barrier properties were not significantly improved. In this work, dialdehyde cellulose nanofibers (DACNF) were obtained through oxidation using sodium periodate and incorporated into SPI film with TT to obtain antioxidant and bacteriostatic properties. With increased DACNF content, the anti-swelling, mechanical and barrier properties of SPI film were enhanced due to a double-crosslinked structure based on the covalent and hydrogen bonds formed between DACNF, TT and SPI. Notably, the SPI film containing 10 % DACNF and 8 % TT exhibited 40.22 % DPPH scavenging activity and inhibited Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) by 47.37 % and 93.8 %, respectively. In packaging applications, the peroxide value of beef tallow and total viable count of cooked pork packaged with 10DTSPI reached 0 g/100 g and 2.26 Log CFU/g, respectively, both significantly lower than those observed with SPI film. So, this work provides a bio-film with both antioxidant and antibacterial properties, demonstrating its potential for packaging oily foods and meat products.