Effects of carbon monoxide treatment before vacuum packaging on the physical parameters and consumer evaluations of raw beef

This study examined the color changes of packaged beef due to the effects of carbon monoxide exposure before vacuum packing and storage time, as well as consumers' evaluations of that beef. In the experiment, 400 striploin steaks (M. longissimus dorsi) were vacuum packed or after 48 hours of exposure to different concentrations of CO (0.1%, 0.3%, and 0.5%) vacuum packed. The color measurements and consumer evaluations were conducted after 7, 10, 14, 17, and 21 days of storage in the dark at 2 +/- 1 degrees C. Consumers evaluated the color, surface discoloration, attractiveness, and their willingness to buy the meat. The results showed that regardless of storage time, the color parameters (L*, a*, b*, C*) were significantly higher for the steaks vacuum packed after exposure to carbon monoxide in comparison to those packaged in a vacuum without the use of CO. Based on the consumer evaluations, the most attractive steaks were those that had been exposed to 0.3% and 0.5% CO, which were characterized by bright red or cherry-red colors. Consumers did not accept the appearance of steaks packaged without the carbon monoxide pretreatment. Exposing meat to CO before packaging allows to obtain the attractive color of vacuum packed beef.