Grobbel J P, Dikeman M E, Hunt M C, Milliken G A
Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506, USA.
J Anim Sci. 2008 May;86(5):1191-9. doi: 10.2527/jas.2007-0479. Epub 2008 Feb 1.
Fresh meat color is a major factor influencing the purchase of meat products by consumers, whereas tenderness is the primary trait determining overall eating satisfaction of consumers. The objectives of this research were to determine the effects of packaging atmosphere on fresh beef color stability, cooked color, and tenderness. Longissimus lumborum muscles (n = 14 pairs) from USDA Select, A-maturity carcasses were assigned to either 14-d tenderness measurement or to display and then to 18-d [80% O(2), 20% CO(2) (HiO(2)) modified atmosphere packaging (MAP)] or 28-d [vacuum package (VP) and ultra low (ULO(2)) plus CO MAP blends] tenderness measurement. Loins were then fabricated on d 7 postmortem into 2.54-cm-thick steaks. Steaks 8 to 10 caudal to the first 7 steaks were bisected, assigned to a packaging treatment, and used for internal cooked color. One full steak was used for initial tenderness. Packaging treatments were as follows: vacuum-packaging (VP); 80% O(2), 20% CO(2) (HiO(2)); 0.4% CO, 35% CO(2), 64.6%N(2) (ULO(2)CO); 0.4% CO, 99.6% CO(2) (ULO(2)COCO(2)); 0.4% CO, 99.6% N(2) (ULO(2)CON(2)); or 0.4% CO, 99.6% Ar (ULO(2)COAr). Steaks packaged in HiO(2) MAP were in dark storage (2 degrees C) for 4 d, and all other steaks were in dark storage for 14 d. Steaks were displayed under fluorescent lighting (2,153 lx; 3,000 K) for 7 d, with instrumental color measured on d 0 and 7 of display. Trained color panelists (n = 10) assigned color scores. Steaks for Warner-Bratzler shear force and cooked color were cooked to 70 degrees C. Steaks packaged in the 4 ULO(2) MAP blends with CO had no change (P > 0.05) or increased (P < 0.05) a* values for fresh color. Steaks packaged in VP or the 4 ULO(2) MAP blends with CO had little or no surface discoloration. Steaks packaged in HiO(2) MAP discolored faster (P < 0.05) and 56% more (P < 0.05) than those in any other packaging treatment. There were no differences (P > 0.05) in Warner-Bratzler shear force on d 14 postmortem. Steaks packaged in HiO(2) MAP were less tender (P < 0.05) than the other treatments at the end of display but had 10 d less aging due to a shorter dark storage period. Steaks packaged in HiO(2) had the lowest (P < 0.05) a* values for internal cooked color of all packaging treatments. Steaks packaged in ULO(2)COCO(2) and VP had intermediate a* values, whereas those packaged in ULO(2)COAr, ULO(2)CO, and ULO(2)CON(2) had the greatest (P < 0.05) a* values for internal cooked color. Ultra-low oxygen packaging treatments had longer fresh color stability than steaks packaged in HiO(2) MAP and equal or better tenderness. Packaging atmospheres altered the internal cooked color, with steaks packaged in HiO(2) MAP exhibiting premature browning.
鲜肉颜色是影响消费者购买肉制品的主要因素，而嫩度是决定消费者整体食用满意度的首要特性。本研究的目的是确定包装气氛对鲜牛肉颜色稳定性、熟肉颜色和嫩度的影响。从美国农业部精选的A级成熟胴体上采集的腰大肌（n = 14对），一部分用于14天的嫩度测量，另一部分先进行展示，然后进行18天的[80%氧气、20%二氧化碳（高氧）气调包装（MAP）]或28天的[真空包装（VP）和超低氧（ULO₂）加二氧化碳气调包装混合物]嫩度测量。然后在宰后第7天将腰肉加工成2.54厘米厚的牛排。从最初的7块牛排向后数第8至10块牛排被切成两半，进行包装处理，并用于内部熟肉颜色的测定。一块完整的牛排用于初始嫩度测定。包装处理如下：真空包装（VP）；80%氧气、20%二氧化碳（高氧）；0.4%一氧化碳、35%二氧化碳、64.6%氮气（ULO₂CO）；0.4%一氧化碳、99.6%二氧化碳（ULO₂CO₂）；0.4%一氧化碳、99.6%氮气（ULO₂CON₂）；或0.4%一氧化碳、99.6%氩气（ULO₂COAr）。采用高氧气调包装（HiO₂ MAP）的牛排于暗处（2℃）储存4天，其他所有牛排于暗处储存14天。牛排于荧光灯下（2153勒克斯；3000开尔文）展示7天，在展示的第0天和第7天测量仪器颜色。由经过培训的颜色评判员（n = 10）给出颜色评分。用于沃纳 - 布拉茨勒剪切力和熟肉颜色测定的牛排煮至70℃。采用4种含一氧化碳的超低氧气调包装混合物包装的牛排，其鲜肉颜色的a值无变化（P > 0.05）或有所增加（P < 0.05）。采用VP包装或4种含一氧化碳的超低氧气调包装混合物包装的牛排表面几乎没有变色。采用高氧气调包装（HiO₂ MAP）的牛排变色速度更快（P < 0.05），比其他任何包装处理的牛排变色程度多56%（P < 0.05）。宰后第14天，沃纳 - 布拉茨勒剪切力无差异（P > 0.05）。在展示结束时，采用高氧气调包装（HiO₂ MAP）的牛排比其他处理的牛排嫩度更低（P < 0.05），但由于暗处储存期较短，其成熟时间少10天。在所有包装处理中，采用高氧气调包装（HiO₂）的牛排内部熟肉颜色的a值最低（P < 0.05）。采用ULO₂CO₂和VP包装的牛排a值居中，而采用ULO₂COAr、ULO₂CO和ULO₂CON₂包装的牛排内部熟肉颜色的a值最大（P < 0.05）。超低氧包装处理的牛排鲜肉颜色稳定性比采用高氧气调包装（HiO₂ MAP）的牛排更长，嫩度相同或更好。包装气氛改变了内部熟肉颜色，采用高氧气调包装（HiO₂ MAP）的牛排出现过早褐变。
