Increased Α-tocopherol Content Research Articles

Effect of Duration of Supplementation of Selenium and Vitamin E on Periparturient Dairy Cows

Cows were fed diets either supplemented with .2ppm Se and 70 IU vitamin E/kg diet DM (21 cows) or unsupplemented (40 cows) during the dry period (∼ 60 d). From parturition to 21 d of lactation, cows were fed diets that were either supplemented with .3ppm Se and 40IU/kg vitamin E or unsupplemented. At d 21 following parturition, 18 cows fed the unsupplemented diet were switched to diets containing 0 or .3ppm supplemental Se and 0 or 40IU/kg supplemental vitamin E arranged factorially. These diets were fed for the next 32 d. The remaining cows continued on their respective diets for 32 d. Plasma Se concentrations averaged .1µg/ml for supplemented cows but were .05μg/ml for unsupplemented cows. Plasma Se concentration from cows fed supplemental Se from 21 to 53 d postpartum increased rapidly and were not different from long-term supplemented cows. Whole blood glutathione peroxidase activity was lower in unsupplemented than in supplemented cows. Short-term Se supplementation increased glutathione peroxidase activity above that for unsupplemented animals, but activity was still less than that in long-term supplemented animals. Plasma α-tocopherol concentrations at parturition and d 21 postpartum were lower in unsupplemented than in supplemented animals. On d 53 postpartum, no differences in plasma α-tocopherol concentrations were found between long-term supplemented and unsupplemented cows. Supplementing vitamin E during the dry period increased α-tocopherol content of colostrum.

Effect of ascorbate and ascorbyl palmitate on lipid oxidation in semi-dry saugages manufactured from pork materials differing in stability towards oxidation

Semi-dry fermented sausages were manufactured from three batches of pork slightly differing in their polyenoic fatty acid levels and α-tocopherol contents. The sausage doughs were treated as follows: (1) control, (2) ascorbate, (3) ascorbyl palmitate and (4) a combination of ascorbate and ascorbyl palmitate. After brine fermentation, products ripened at 15°C were evaluated for rancidity by peroxide values and TBA numbers. During ripening important differences in stability towards oxidation were generally not observed. Both peroxide and TBA values gradually increased linearly with time. For the TBA values, gradients for the products derived from the three diet groups differed considerably. Only two of six batches containing increased levels of α-tocopherol and product antioxidants exhibited slightly improved stability towards oxidation, as judged by peroxide and TBA values. Sensory evaluations, performed only on the product series containing ascorbate, failed to reveal any positive effect in favour of the increased α-tocopherol content. Thus, for semi-dry sausages manufactured from pork materials with a slightly increased sensitivity towards oxidation, results indicated with there was little advantage to increasing the levels of α-tocopherol in the meat by dietary means or to changing the current commercial practice of adding ascorbate to the sausage doughs.