THE ANTIOXIDATIVE ACTIVITY OF RRR-ALPHA-TOCOPHEROL VS RRR-DELTA-TOCOPHEROL IN COMBINATION WITH ASCORBYL PALMITATE IN COOKED, MINCED TURKEY

RRR-alpha-tocopherol and RRR-delta-tocopherol (100 or 200ppm) had simi lar and significantly better antioxidative effects compared to ascorby l palmitate (200 ppm) in turkey meat balls during storage at 5 degrees C for up to 9 days, as determined by measurement of thiobarbituric ac id reactive substances (TBARS) and by static head space detection of h exanal. The antioxidative effect of alpha-tocopherol at 100ppm was, me asured as a reduction of head space hexanal, significantly enhanced by ascorbyl palmitate (200 ppm), resulting in a further 50% reduction co mpared to (d)elta-tocopherol. At the 200-ppm level, only the antioxida tive activity of alpha-tocopherol was enhanced significantly by ascorb yl palmitate (200ppm), in contrast to the effect on the antioxidative activity of delta-tocopherol (200ppm). The antioxidative activity obta ined by alpha-tocopherol at the 100-ppm level in combination with asco rbyl palmitate (200 ppm) was similar to the effect obtained by alpha-t ocopherol at the 200-ppm level in combination with ascorbyl palmitate (200 ppm) measured as head space hexanal. Ascorbyl palmitate was in al l storage experiments depleted in the product at a rate which appeared to be independent of the presence of tocopherols. Of the tocopherol h omologues, alpha-tocopherol was most affected by the presence of ascor byl palmitate, and the concentration of alpha-tocopherol was found to decrease during storage in the absence of ascorbyl palmitate, in contr ast to when ascorbyl palmitate was present. A similar effect of ascorb yl palmitate was less evident for delta-tocopherol and for gamma-tocop herol in a natural mixture of the tocopherol homologues added to turke y meat balls. Copyright (C) 1996 Elsevier Science Ltd