Mg Malondialdehyde Research Articles

Evaluation of the antioxidant potential of grape seed and bearberry extracts in raw and cooked pork

The effect of grape seed extract (GSE) and bearberry (BB), on lipid oxidation (TBARS, mg malondialdehyde (MDA)/kg muscle), colour (CIE ‘ a’ redness value), pH, microbial status (log 10CFU colony forming units/g pork) and sensorial properties of cooked pork patties was investigated. GSE (0–1000 μg/g muscle) and BB (0–1000 μg/g muscle) were added to raw pork ( M. longissimus dorsi) patties which were stored in modified atmosphere packs (MAP) (75% O 2:25% CO 2) for up to 12 days at 4 °C. Cooked pork patties were stored in MAP (70% N 2:30% CO 2) for up to 4 days at 4 °C. Mesophilic plate counts and pork pH were unaffected by GSE and BB. GSE and BB addition decreased ( P < 0.05) lipid oxidation (TBARS) in raw pork patties on days 9 and 12 of storage, relative to controls. Antioxidant activity of GSE and BB was observed in cooked pork patties demonstrating the thermal stability of GSE and BB. The ‘ a’ redness values of raw and cooked pork patties marginally increased with increasing GSE concentration. The sensory properties of cooked pork patties were unaffected by GSE and BB addition. Results obtained demonstrate the potential for using health promoting nutraceuticals in meat and meat products.

Combined effect of oregano essential oil and modified atmosphere packaging on shelf-life extension of fresh chicken breast meat, stored at 4 °C

The combined effect of oregano essential oil (0.1% and 1% w/w) and modified atmosphere packaging (MAP) (30% CO 2/70% N 2 and 70% CO 2/30% N 2) on shelf-life extension of fresh chicken meat stored at 4 °C was investigated. The parameters that were monitored were: microbiological (TVC, Pseudomonas spp., lactic acid bacteria (LAB), yeasts, Brochothrix thermosphacta and Enterobacteriaceae), physico-chemical (pH, TBA, color) and sensory (odor and taste) attributes. Microbial populations were reduced by 1–5 log cfu/g for a given sampling day, with the more pronounced effect being achieved by the combination of MAP and oregano essential oil. TBA values for all treatments remained lower than 1 mg malondialdehyde (MDA) kg −1 throughout the 25-day storage period. pH values varied between 6.4 (day 0) and 5.9 (day 25). The values of the color parameters L*, a* and b* were not considerably affected by oregano oil or by MAP. Finally, sensory analysis showed that oregano oil at a concentration of 1% imparted a very strong taste to the product for which reason these lots of samples were not scored. On the basis of sensory evaluation a shelf-life extension of breast chicken meat by ca. 3–4 days for samples containing 0.1% oregano oil, 2–3 days for samples under MAP and 5–6 days for samples under MAP containing 0.1% of oregano oil was attained. Thus oregano oil and MAP exhibited an additive preservation effect.

Use of α‐tocopherol acetate to improve fresh pig meat quality of full‐fat rapeseed‐fed pigs

AbstractThirty‐two pigs were allocated to one of four diets, FFRD0 and FFRD200, containing full‐fat rapeseed (FFR), 150 g/kg [25–50 kg liveweight (LW)], and 250 g/kg (50–90 kg LW), or CD0 and CD200, containing equivalent quantities of rapeseed meal and 34 g/kg (25–50 kg LW) or 59.2 g/kg (50–90 kg LW) coconut oil and lard (0.5:0.5, w/w). Diets FFRD200 and CD200 were supplemented with 200 mg/kg α‐tocopherol acetate (ATA). ATA supplementation significantly (P&lt;0.001) reduced muscle drip loss. The melting point (°C) of subcutaneous fat was significantly lowered by FFR (P&lt;0.001) but increased by ATA supplementation (P&lt;0.05). Tissue α‐tocopherol (AT) concentrations were significantly increased by ATA supplementation. Longissimus dorsi AT concentration was positively correlated with AT concentration in subcutaneous fat (r=0.86) and in plasma at 35 (r=0.65) and 77 (r=0.85) days of feeding (P&lt;0.001). In both L. dorsi and subcutaneous adipose tissue lipids, FFRD caused a significant (P&lt;0.001) decrease in the ratio of n‐6 to n‐3 fatty acids and a significant (P&lt;0.001) increase in the ratio of polyunsaturated to saturated fatty acids. AT supplementation significantly reduced the susceptibility of L. dorsi and subcutaneous fat to lipid oxidation during storage at 4°C for up to 16 d. For all dietary treatments and storage times, lipid oxidation [mg malondialdehyde (MDA)/kg muscle] was greater in the surface layer (0–2.5 mm) of L. dorsi than below the surface (2.5–5 mm). Oxidative stability of L. dorsi lipids to iron‐induced lipid peroxidation was significantly improved (P&lt;0.001) by AT supplementation. Meat from pigs fed FFRD diets was significantly less stable to iron‐induced oxidation (nmoles MDA/mg protein) at the longer incubation periods (100 and 200 min). The susceptibility of L. dorsi to iron‐induced lipid oxidation decreased as the ratio of the tissue concentration of AT to unsaturated fatty acid increased.