Dietary Effects of Oregano ( L.) Plant or Sweet Chestnut ( Mill.) Wood Extracts on Microbiological, Chemico-Physical Characteristics and Lipid Oxidation of Cooked ham During Storage.

The aim of this study was to evaluate the dietary effect of feeding pigs with diets enriched with sweet chestnut wood ( Mill.) or oregano ( 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 (ORAC 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), count, , pH value, colour coordinates (L*, a*, b*), total basic volatile nitrogen (TBVN) and thiobarbituric reactive substances (TBARs) determinations. No differences in TMC, LAB and count, pH, TBVN, chemical composition and L* values were registered between the three groups at all the sampling times considered. No was detected in the samples tested. Significant differences were registered for ORAC at 0 days, a* and b* values and TBARs value at 10 and 20 days of storage, with higher values for ORAC, 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.