The aim of this study was to evaluate the dietary effect of feeding pigs with diets enriched with sweet chestnut wood (<em>Castanea sativa</em> Mill.) or oregano (<em>Origanum vulgaris</em> L.) extract on the microbiological and chemical characteristics of cooked pork ham. Three groups of 10 pigs were fed with a control diet (CTRL), with the CTRL diet enriched with 0.2% of oregano extract (OR) and with the CTRL diet enriched with 0.2% of sweet chestnut wood extract (SCW), respectively. Six cooked hams per group were produced, sliced and packaged under a modified atmosphere (N2:CO2=80:20) and stored at refrigeration temperature (4±1°C). Three packages per cooked ham were sampled for analyses at three different storage times (0, 10 and 20 days). At day 0 time, antioxidant capacity of the products (ORACFL assay) and chemical composition were performed. At each sampling time, from all the samples the following analyses were performed: Total Microbial Count (TMC), Lactic Acid Bacteria count (LAB), <em>Enterobacteriaceae</em> count, <em>Listeria monocytogenes</em>, pH value, colour coordinates (L*, a*, b*), total basic volatile nitrogen (TBVN) and thio-barbituric reactive substances (TBARs) determinations. No differences in TMC, LAB and <em>Enterobacteriaceae</em> count, pH, TBVN, chemical composition and L* values were registered between the three groups at all the sampling times considered. No <em>Listeria monocytogenes</em> was detected in the samples tested. Significant differences were registered for ORACFL at 0 days, a* and b* values and TBARs value at 10 and 20 days of storage, with higher values for ORAC<sub>FL</sub>, a* and b* values and lower values for TBARs in SCW and OR than CTRL. No antimicrobial effect could be recorded for OR and SCW but a higher oxidative stability, also highlighted by the colour maintenance, was observed in both OR and SCW.
Evaluation of bacteriocin-producing Lactobacillus sakei 1 against Listeria monocytogenes 1/2a growth and haemolytic activity