Novel polyisoprene based UV-activated oxygen scavenging films and their applications in packaging of beef jerky

Abstract

In this study, polyisoprene (PS), a natural rubber with 5, 10, and 20% (w/w) concentrations, was incorporated into low-density polyethylene (LDPE) matrix to develop novel oxygen-scavenging films. UV light was utilized to activate the oxygen-scavenging reaction in the film. The resulting OS films were analyzed for Fourier transform infrared (FTIR) spectra, mechanical, barrier, thermal properties, and oxygen-scavenging capabilities. The tensile strength (TS) and elongation break (EB) of the LDPE/PS 20% films did not affect with the addition of PS and increased 6.13 ± 0.43 to 6.91 ± 0.77 MPa and from 121.39 ± 0.23 to 132.01 ± 0.93%, respectively. However, barrier properties were greater than those of pure LDPE films. The thermal stability of the resulting LDPE/PS films was improved upon the introduction of PS. The prepared LDPE/PS 10% and 20% films had 13.6 and 16.72 mL O2/g oxygen-scavenging capacity, respectively. Beef jerky packed with the LDPE/PS 20% film increased its stability, color, and pH during storage. Further, on analyzing lipid oxidation, LDPE/PS 20% was effective as butylated hydroxytoluene to maintain the oxidative stability of beef jerky. Jerky packed with LDPE/PS 10% and 20% films had a significantly decreased microbial count after storage for 90 d (p < 0.05).