Effect of PLA films containing propolis ethanolic extract, cellulose nanoparticle and Ziziphora clinopodioides essential oil on chemical, microbial and sensory properties of minced beef

This study was conducted to examine the effects of polylactic acid (PLA) film containing propolis ethanolic extract (PE), cellulose nanoparticle (CN) and Ziziphora clinopodioides essential oil (ZEO) on chemical, microbial and sensory properties of minced beef during storage at refrigerated temperature for 11 days. The initial total volatile base nitrogen (TVB-N) was 8.2 mg/100 g and after 7 days reached to 29.1 mg/100 g in control, while it was lower than 25 mg/100 g for treated samples. At the end of storage time in control samples peroxide value (PV) reached to 2.01 meq peroxide/1000 g lipid, while the values for the treated samples remained lower than 2 meq peroxide/1000 g lipid. Final microbial population decreased approximately 1-3 log CFU/g in treated samples compared to control (P < 0.05). Films containing 2% ZEO alone and in combination with different concentrations of PE and CN extended the shelf life of minced beef during storage in refrigerated condition for at least 11 days without any unfavorable organoleptic properties.