No abstract

The aim of this study was to assess the effects of a range of carbon monoxide (CO) concentrations and exposure times on the colour stability and shelf-life of vacuum packaged Longissimus thoracis et lumborum (LTL) beef steaks. Steaks were exposed to five pretreatments: 0 (Control), 0.4, 1, 3 and 5% CO combined with 60% CO 2, (balance N 2) for 5, 7 or 24 h. They were then vacuum packed and stored at 2°C for 28 days. The optimum pretreatment was 1% CO for 5 h as this enhanced initial desirable colour yet allowed discolouration to reach unacceptable levels (a* = 12, C* = 16) by the use-by-date (28 days). K/S ratios verified that the optimum CO pretreatment does not mask spoilage. All CO pretreatments had no effect on pH or purge loss (P > 0.05). Reducing the CO concentration and decreasing the exposure time achieved a desirable colour, without masking spoilage, thereby minimizing the processing time and improving the safety of workers.

No abstract

The effect of CO pretreatments applied to beef striploin steaks (Longissimus thoracis et lumborum, LTL) prior to vacuum packaging and display temperature on colour stability, shelf life and tenderness was determined. Steaks were exposed to 5% CO, 60% CO and 35% N for 3 (CO3), 5 (CO5) or 7 (CO7) h, followed by 28 days display at 2 °C (good industry practice) or 6 °C (mild abuse). CO5 was the optimum exposure time as it induced the desirable colour while not retaining the bright colour, irrespective of display temperature. K/S ratios confirmed that CO pretreatment did not mask spoilage and could be more sensitive than colour parameters at monitoring discoloration as colour was not retained. Exposure to CO did not have any negative effect on meat quality attributes, while mild temperature abuse (6 °C) increased purge loss and decreased pH.

This study investigated the effects of CO-pretreatments on three bovine muscles: Psoas major (PM), Gluteus medius (GM) and Semitendinosus (ST) on colour stability and quality attributes under anaerobic conditions. Steaks were exposed to one of four pretreatments: 1% CO for 5 h, 5% CO for 5 h, 1% CO for 24 h, with 60% CO (balance N) or untreated (control) and then vacuum packaged and displayed (28 days at 2 °C). CO pretreatments improved redness for colour labile muscles (PM and GM). The optimum CO pretreatment was 1% for 5 h as this induced surface redness while discolouring (a* = 12, C* = 16) by the use-by-date (28 days). CO pretreatments decreased protein oxidation (P < 0.01), and had no negative effect on pH and spoilage bacteria (P > 0.05). Applying a 1% CO pretreatment for 5 h effectively enhanced the colour of various muscles while not masking spoilage thus addressing consumer concerns.