The effect of essential oil of Anethum graveolens L. seed and gallic acid (free and nano forms) on microbial, chemical and sensory characteristics in minced meat during storage at 4 °C

The aim of this study was to evaluate the effect of gallic acid (GA) and essential oil (EO) of Anethum graveolens L. seed (forms of nanoliposome and free) on bacteriological, chemical and sensory properties of minced meat during storage. In this research, Escherichia coli (gram negative) and Staphylococcus aureus (gram positive) were used to examine the effect of these compounds on meat. The particle sizes (z-average diameter) of prepared nanoliposomes of EO and GA were in the range of 141 to 165 nm and 146–160 nm, respectively and the efficiency of encapsulation (EE %) in the current research was 51.76–69.8% in nano EO (NEO) and 53.23–67.07% in nano gallic acid (N-GA). Also, the outcomes indicated the treatment containing nano-liposomes had a better antimicrobial effect in both of bacteria. In present study, the Minimum Inhibitory Concentration (MIC) of GA, N-GA, EO and NEO for S. aureus was 0.62 ± 0.01, 0.62 ± 0.02, 0.62 ± 0.01 and 0.62 ± 0.01 mg/mL, respectively, and for E. coli was 0.62 ± 0.01, 0.62 ± 0.01, 1.25 ± 0.1 and 1.25 ± 0.1 mg/mL, respectively. Also, the results showed MBC (The Minimum Bactericidal Concentration) of GA, N-GA, EO and NEO for S. aureus was 0.62 ± 0.02, 0.62 ± 0.03, 1.25 ± 0.1 and 1.25 ± 0.1 mg/mL, respectively, and for E. coli was0.62 ± 0.01, 1.25 ± 0.1, 2.5 ± 0.2, 2.5 ± 0.2 mg/mL, respectively. The highest and lowest of 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging were detected, in the Butylated hydroxytoluene (BHT) 200 and EO1%, respectively. Furthermore, after 18 day, minimum pH and Total volatile basic nitrogen (TVB-N) value were related to the N-GA2% on S. aureus with pH = 6.5 and NEO group (27 mg N/100 g), respectively. Finally, the treatment of NEO showed a higher acceptance score of sensory evaluation after 18 days. According to the outcomes of current investigation, the use of nanocapsulated EO and GA are effective (as a coating for food storage) and can increase the shelf life of minced meat.