Background  

Consumers are conditioned to purchase beef that is bright, cherry‐red in color and free of discoloration or blemish. Various packaging systems are used to obtain the desired color. Oxidative and enzymatic processes may be initiated by the meat package systems and display conditions. Oxidation is responsible for the development of off odors and flavors in cooked beef products. This study aimed to characterize the effects of packaging and display on meat flavor so recommendations can be made to the industry to maximize consumer satisfaction. In this study, volatile compounds were collected and compared with sensory data to identify packaging types and mechanisms responsible for flavor development, and variation in beef flavor.  

Methodology  

Paired strip loins and top sirloin butts were collected from USDA Choice, “A” maturity beef carcasses (n = 10) from a commercial processing facility in the Texas panhandle. All subprimals were packaged under vacuum, stored in dark storage at 0‐4°C and aged for 14d. After initial aging, all top butts and strip loins were fabricated and sliced to produce 2.54cm Gluteus medius (GM) and Longissimus dorsi (LD) steaks, respectively. At 14d, steaks from each muscle group were randomly assigned to 1 of 5 package types: high‐oxygen modified atmosphere lidded trays (80 % O₂/20 % CO₂, HIOX), carbon monoxide modified atmosphere lidded trays (0.4 % CO/30 % CO₂/69.6%N₂, CO), rollstock (forming and non‐forming films, ROLL), vacuum packaging without retail display (VAC), and traditional overwrap (OW). The OW packages remained under vacuum prior to being placed on foam trays and sealed with polyvinyl chloride (PVC) film and displayed in retail cases on d 21 postmortem. All package types were placed in dark storage at 0‐4°C for an additional 7d prior to display. At 21d postmortem, HIOX, OW, CO, and ROLL packages were removed from dark storage and displayed in coffin‐style retail cases (0‐2°C) for 48hrs under continuous fluorescent lighting, while VAC steaks remained in dark storage.     

Consumer panelists evaluated samples for overall liking, liking of flavor, tenderness, and juiciness. Trained panelists evaluated samples for the following attributes: beef flavor identity, brown/roasted, bloody/serumy, fat‐like, liver‐like, oxidized, cardboardy, umami, sweet, salty, bitter, sour, overall Juiciness, and overall tenderness. Volatile compounds were determined by head space solid phase micro‐extraction followed by gas chromatography mass spectrometry.  

Findings

Consumer flavor liking was greatest for ROLL and VAC package types. The flavor liking scores for OW and CO were lower than ROLL, but similar to VAC. Flavor liking of HIOX was lowest compared to all other packaging types. Samples from HIOX packaging had the greatest scores for oxidized and cardboardy, while having the lowest response for beef flavor identity and umami compared to all other packaging types. Increased quantities of volatile lipid oxidation products, in addition to a decrease in Maillard products, segregated GM HIOX samples from all others. There was a separation between muscles on the basis of increased Strecker aldehydes and pyrazines in the LD and increased sulfur compounds associated with the GM.         

Implications    

Considering the combination of all these results it is evident that packaging environment impacts beef flavor. Package types which have greater levels of oxygen were detrimental to flavor. Furthermore, this detrimental impact on flavor was magnified in muscles which have lower chemical stability. Future efforts should be made to explore packaging technologies which do not have detrimental effects on flavor. Furthermore, vacuum packaging may be recommended for less chemically stable muscles.