Effects of differing carbon dioxide levels on meat color in modified atmosphere packaging

Abstract

The objective of this study was to assess the effect of different carbon dioxide (CO2) concentration gas flushes in master packages on the display life of fresh beef. Twenty-five USDA Low Choice ribeye rolls (IMPS 112A) from carcasses in program G-87B (USDA-AMS; live specification - Angus) were collected from Creekstone Farms in Arkansas City, KS. Each sub-primal was wet aged for 12 d. After aging, each sub-primal was opened and over sprayed with a SYNTRx 3300 solution. Ribeye rolls were sliced 2.54 cm thick and placed onto foam trays (n = 108 trays) with an absorbent pad and over-wrapped with perforated polyolefin film. Trays were randomly assigned to either a 10%, 20% or 30% CO2 concentration master bag (n = 27 master bags; n = 9/CO2 concentration). Three master bags, containing four trays, for each CO2 concentration (10%, 20% and 30%) were randomly selected for opening after 10, 15, 18 d of dark storage, and the trays were placed in a display case for retail display evaluation for 5 d. Headspace analysis was conducted before each master bags were opened, and objective color measurements were collected on d 0 - 5 of retail display. Muscle color, surface discoloration and overall acceptability were analyzed daily by a trained panel (n = 6). The results of this study showed steaks from the 10% CO2 concentration darkened and discolored more (P < 0.05) rapidly than steaks from either the 20 or 30% CO2 concentrations. Additionally, steaks from master bags flushed with the 10% CO2 concentration were the only steaks in display to reach unacceptable levels and discrimination by consumers. Steaks from master bags flushed with 20 or 30% CO2 concentration performed comparably (P > 0.05) with minimal differences. The 20% CO2 concentration master bag flush outperformed the 10% CO2 concentration in all aspects of the study, as well as surpassed or equaled the 30% CO2 concentration. Thus, it is recommended 20% CO2 concentration gas flush of master bags could be utilized by the industry to reduce CO2 use.