Effect of black pepper essential oil on the quality of fresh pork during storage

• Black pepper essential oil (BPEO) decreased TBARS and MetMb% values at 3, 6 and 9 days.
• BPEO treatments have higher L* and a* and lower b* values than the control at 6 and 9 days.
• BPEO has higher activity against Gram-negative bacteria than Gram-positive bacteria.
• The inhibition of Pseudomonas spp. and Enterobacteriaceae by BPEO was dose-dependant.

The effect of different concentrations (0, 0.1 and 0.5%, v/v) of black pepper essential oil (BPEO) on thiobarbituric acid reactive substances (TBARS), meat color, the percentage of metmyoglobin (MetMb%), microbiological parameters and total volatile basic nitrogen (TVB-N) of pork loins stored at 4 °C for 9 days was evaluated. BPEO treatments showed lower TBARS, MetMb%, yellowness (b*) values, Pseudomonas spp. and Enterobacteriaceae count and TVB-N values and higher lightness (L*) and redness (a*) values than the control during storage; the effectiveness of BPEO was dose-dependent. The retardation of the formation of MetMb by adding BPEO ensured higher L* and a* values and lower b* values than the control at 6 and 9 days; the MetMb content has a similar trend to the lipid oxidation. The lower TVB-N value of BPEO treatments than the control could be attributed to the inhibition of Pseudomonas spp. and Enterobacteriaceae. Gram-negative bacteria were more sensitive than Gram-positive bacteria to BPEO.