Reduced nitrite levels and dietary α-tocopheryl acetate supplementation:: effects on the colour and oxidative stability of cooked hams

The objective of the present study was to determine the effects of dietary vitamin E supplementation and reduced nitrite levels on the colour stability of cooked hams. Large white x Landrace pigs (male n = 6, female n = 6) were each subdivided into two groups (n = 3) and fed an alpha-tocopheryl acetate supplemented diet (1000 mg/kg feed) and a basal diet (10 mg/kg feed) for a period of 10 weeks. M. semitendinosus were removed from each pig, divided into light and dark pigmented fractions, vacuum packed and stored at 4 degrees C for 24 h. Muscles were cured with input nitrite levels of 25 and 100 mg/kg meat and were tumbled and massaged for 17 h. Samples were cooked, sliced and overwrapped in a high oxygen permeable film for a storage period of 10 days. Surface colour of hams was measured and expressed as Hunter 'a' values. Concentrations of a-tocopherol were significantly (P < 0.001) greater in supplemented muscles compared to basal muscles for both male and female pigs. Hams manufactured from male and female supplemented pigs resulted in significantly (P < 0.001) higher Hunter 'a' values than hams manufactured from male and female pigs receiving the basal diet. Muscles cured with 100 mg nitrite/kg meat formed products with significantly (P < 0.001) higher 'a' values than those cured with the lower (25 mg/kg meat) nitrite level. Hams manufactured from supplemented muscles, treated with 25 mg nitrite/kg meat showed significantly (P < 0.05) higher Hunter 'a' values than hams manufactured from basal muscles, treated with 100 mg nitrite/kg meat. Hams manufactured from female porcine muscles had significantly (P < 0.001) higher 'a' values than hams from male muscles during the 10 days of simulated retail display. No such gender differences were observed for TEARS values. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.