Effect of storage and cooking on the oxidative stability of pork
Haak, L.; Smet, K.; Raes, K.; Claeys, E.; Paelinck, H.; De Smet, S.
Communications in Agricultural and Applied Biological Sciences 69(2): 143-146
2004
ISSN/ISBN: 1379-1176 PMID: 15560208 Document Number: 580969
The objective of this study was to assess the efficacy of supplemental vitamin E or an antioxidant cocktail (AOC) ( alpha -tocopherol acetate+rosemary+citric acid+gallic acid) in the diets of pigs (200 ppm) to maintain the oxidative stability of pork meat, either or not cured, during cooking and storage. The oxidative stability was assessed by colour stability measurement, fat and protein oxidation. Slices (2.5 cm) of the Longissimus thoracis (LT) were wrapped in an oxygen permeable polyethylene film and placed in an illuminated chill cabinet (900 lux, 3 degrees C) for 9 days. Cooked cured hams were manufactured immediately after slaughtering. LT samples were cooked in a waterbath at 70 degrees C for 40 min after 10 months of frozen storage. The samples of the cooked cured ham and cooked pre-frozen LT were also sliced, overwrapped and placed in the illuminated chill cabinet for 7 days. Colour oxidation (CIELAB, reflectance values) for the fresh LT was determined on 3, 6 and 9 days of storage in the chill cabinet, whereas for the cooked cured ham the measurements took place at several time points during the first day of storage followed by a single measurement on the following days. Lipid oxidation was assessed by TBARS analysis. Raw LT samples were assayed for lipid oxidation after 3, 6 and 9 days of storage in the chill cabinet. Cooked pre-frozen LT samples and cooked cured ham samples were analysed after 1 and 7 days of storage in the chill cabinet. Oxidative damage to proteins was assessed by carbonyl and thiol groups measurement. The protein oxidation analysis were performed on the raw LT and the cooked cured ham samples. The results illustrate that there were no considerable effects of fat or antioxidant source on colour stability for the fresh LT or the cooked cured ham. Lipid oxidation in fresh LT and cooked cured ham is well controlled during display (TBARS<0.5 g/kg) although the antioxidant effect of neither the AOC nor vitamin E was strong enough to control lipid oxidation in uncured cooked meat stored under aerobic conditions. The results of protein oxidation are difficult to interpret because there seems to be no unambiguous relationship between protein oxidation, measured by carbonyl or by thiol content and furthermore there is no clear link of protein with fat oxidation.