Oxidative stability of chicken meat at different oxygen concentrations in the packaging unit

The aim of this study was to preserve the quality and prevent the colour, lipid and protein oxidation in chicken breast fillet (pectoralis major muscle) during storage. For this purpose, modified atmospheres (MA) with four different gas mixtures (vol. %) of oxygen (O2 ), carbon dioxide (CO2 ) and nitrogen (N2 ) were used: oxygen free (0: 20: 80), low (20: 20: 60), medium (40: 20: 40), and high oxygen MA (70: 20: 10). After 9 days of storage in a refrigerator at 2 ± 1 °C, pH was measured, colour was evaluated instrumentally and sensorially, the basic chemical composition, thiobarbituric acid reactive substances (TBARs), and protein carbonyl content of raw chicken breast were determined. After thermal treatment (82 °C, 1 hour, sous-vide) of the breast fillet, the sensory characteristics of odour and aroma were evaluated, and the texture (Warner-Bratzler shear force) was measured instrumentally. The composition of the gas mixture affected all oxidation dependent parameters: (i) colour: L* and b* values were the highest under all MA with oxygen, and the a* value under MA without, medium and high-oxygen, (ii) lipids: the TBARs increased significantly under high oxygen MA after 7 days of storage (below the sensory thresholds value for rancidity), (iii) proteins: protein carbonyl content was the highest under medium and high oxygen MA, and (iv) sensory properties: colour oxidation and intensity of odd aromas under all MA with oxygen, as well as odour and aroma of stale in oxygen-free MA were increased. For chicken breast the most suitable is packaging under modified atmosphere without O2 , because the oxidation rate of colour, lipids and proteins during storage was the lowest. Cilj ovog istraživanja bio je sačuvati kvalitetu i spriječiti oksidaciju boje, lipida i proteina u filetima pilećih prsa (mišić pectoralis major) tijekom skladištenja. U tu svrhu korištene su modificirane atmosfere (MA) s četiri različite mješavine plinova (vol. %) i to kisika (O2 ), ugljikovog dioksida (CO2 ) i dušika (N2 ). MA su bile: bez kisika (0: 20: 80), s niskim sadržajem kisika (20: 20: 60), sa srednjim sadržajem kisika (40: 20: 40) i atmosfera s visokim sadržajem kisika (70: 20: 10). Nakon 9 dana skladištenja u hladnjači pri 2 ± 1 °C izmjeren je pH, boja je ocijenjena instrumentalno i senzorski te su utvrđeni osnovni kemijski sastav, reaktivne tvari tiobarbiturne kiseline (TBAR) i proteinsko-karbonilni sadržaj sirovih pilećih prsa. Nakon termičkog tretmana (82 °C, 1 sat, sous-vide