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 similar and significantly better antioxidative effects compared to ascorbyl palmitate (200 ppm) in turkey meat balls during storage at 5 degrees C for up to 9 days, as determined by measurement of thiobarbituric acid reactive substances (TBARS) and by static head space detection of hexanal. The antioxidative effect of alpha-tocopherol at 100ppm was, measured as a reduction of head space hexanal, significantly enhanced by ascorbyl palmitate (200 ppm), resulting in a further 50% reduction compared to (d)elta-tocopherol. At the 200-ppm level, only the antioxidative activity of alpha-tocopherol was enhanced significantly by ascorbyl palmitate (200ppm), in contrast to the effect on the antioxidative activity of delta-tocopherol (200ppm). The antioxidative activity obtained by alpha-tocopherol at the 100-ppm level in combination with ascorbyl palmitate (200 ppm) was similar to the effect obtained by alpha-tocopherol at the 200-ppm level in combination with ascorbyl palmitate (200 ppm) measured as head space hexanal. Ascorbyl palmitate was in all storage experiments depleted in the product at a rate which appeared to be independent of the presence of tocopherols. Of the tocopherol homologues, alpha-tocopherol was most affected by the presence of ascorbyl palmitate, and the concentration of alpha-tocopherol was found to decrease during storage in the absence of ascorbyl palmitate, in contrast to when ascorbyl palmitate was present. A similar effect of ascorbyl palmitate was less evident for delta-tocopherol and for gamma-tocopherol in a natural mixture of the tocopherol homologues added to turkey meat balls. Copyright (C) 1996 Elsevier Science Ltd