EFFECTS OF DIETARY VITAMIN-E SUPPLEMENTATION AND PACKAGING ON THE QUALITY OF MINCED BEEF

Friesian cattle, aged 26-27 months, were fed a diet supplemented with 2000 IU alpha-tocopheryl acetate/kg feed/day and another group was fed a basal diet (20 IU/kg feed/day) for approximately 50 days prior to s laughter. Following frozen storage (-20 degrees C for 8 weeks) semimem branosus muscles from basal and a-tocopheryl acetate supplemented catt le were minced and vacuum packaged, aerobically packaged or packaged u nder modified atmospheres (MAP) (30% O-2: 70% CO2; 70% O-2: 30% CO2; 8 0% O-2: 20% CO2). Samples were held under refrigerated (4 degrees C) d isplay (fluorescent lighting, 616 lux) for eight days. Vacuum-packaged samples were held under similar conditions hut in complete darkness a nd allowed to bloom for a minimum of 4 hr prior to taking colour readi ngs. TBARS values and Hunter a values in minced beef were measured eve ry two days. alpha-Tocopherol concentrations were significantly (p < 0 .05) higher in minced meat samples from the supplemented group than in the basal group. Significant (p < 0.05) reductions in alpha-tocophero l concentrations in supplemented meat samples were observed with incre ased concentrations of oxygen in different packaging systems after eig ht days of refrigerated storage. TBARS values were reduced over the wh ole retail display period for all packaging systems when alpha-tocophe ryl acetate supplemented beef was used. TBARS values increased as oxyg en levels increased in MAP. Hunter a values showed that vitamin E supp lementation in combination with vacuum packaging and MAP improved the colour stability of meat during the first 4 days of storage, however, the failure of MAP to extend meat colour for longer periods of time wa s probably the result of prior storage at -20 degrees C for 8 weeks. ( C) 1998 Elsevier Science Ltd. All rights reserved