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This study investigated the aptness of modified atmospheric packaging (70:30, O 2 :CO 2 (O_MAP); 70:30, N 2 :CO 2 (N_MAP)) and traditional overwrap (control) for previously frozen ostrich steaks, stored at 4 ± 1°C for 10 days. The N_MAP showed the least oxidation, O_MAP the highest and the control moderate. The redness (CIE a*) decreased to 3.67 ± 0.83 by day 10 in the O_MAP, the N_MAP and control initially had lower values indicating slower oxidisation. The free carbonyl production was higher in the O_MAP than the N_MAP and control. TBARS remained relatively constant for the N_MAP and control, but increased to 9.70 ± 3.26 (day 10) in the O_MAP. Drip loss (non-cumulative), was initially high (5-6%) for N_MAP and control, followed by a decrease on day 2 (2%) that increased to day 10 (4-6%). In conclusion, the traditional overwrap was not suited; N_MAP holds potential under a true anoxic atmosphere whilst O_MAP was limited by protein and lipid oxidation.

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The aim of this study was to investigate the interaction between different rates of freezing and thawing on whole ostrich moon steaks to establish a combination or singular main effect that minimises thaw loss and maximises the retail display shelf-life regarding moisture loss, colour, lipid oxidation and tenderness. Five characteristic freezing rates (FR: 1, 2, 4, 8, 24 h) were compared with five characteristic thawing rates (TR: 1.5, 3, 6.5, 14, 21 h) in a completely randomised block design. Moon steaks (M. femorotibialis medius) from 125 birds were randomly assigned to a specific treatment combination before being subjected (after thawing) to a 10-day chilled storage at 4 °C shelf-life trial. Thawing rate had no effect (p > 0.05) on any of the quality (colour, drip and cooking losses, shear force, 2-thiobarbituric acid (TBARS)) parameters whilst freezing rate and display time both had significant (p < 0.05) influences. Thaw loss was lowest (p < 0.05) for the FR_1h and FR_2h, followed by FR_4h, FR_8h and FR_24. The FR_1h had the highest (p < 0.05) drip and shear force values during display while the FR_2h and FR_8h had the highest rate of oxidation (TBARS and metmyoglobin formation). FR_24h had the second best (p < 0.05) colour retention after FR_4h and minimal package drip. Overall, FR_4h resulted in the best quality meat over the entire shelf-life with high bloom retention, low TBARS and shear force, and average thaw, drip and cooking loss.