The REMEDIAL AND PREVENTATIVE EFFECT OF DIETARY Α‐TOCOPHEROL ON THE DEVELOPMENT OF FISHY FLAVOR IN TURKEY MEAT

Abstract

SUMMARY THREE EXPERIMENTS were conducted to evaluate the preventative and remedial effect of α‐tocopherol on the development of fishy flavor in turkeys fed fish oils. It was found that about 200 mg/kilo α‐tocopherol acetate afforded optimum prevention of fishy flavor in turkeys fed as much as 2% tuna oil in their rations. Withdrawal of fish oil and beef fat substitution for 2 wk before slaughter, caused some decline in fishiness. The addition of α‐tocopherol to the beef fat diet significantly accelerated the decline of fishiness in breast meat. It was also noted that the oil (tuna) used in these experiments contain many fold higher levels of long chain linolenates (ω‐3 fatty acids) than other fish meals (oils) used to feed poultry. There, it is more than a specious argument to assume that less o‐tocopherol acetate would be required to achieve the same effect with such oils since fishiness is related to linolenate content. Tocopherol injection 72, 48 and 24 hr before slaughter was as effective as feeding it concomitantly with fish oil in the reduction of fishiness in the thigh meat and skin. The same trend was noted for breast meat although not statistically significant. Further work is needed to more accurately assess the value of injection. Fatty acid distribution analyses were performed on the extracted lipids from the breast meat of turkeys from all treatments. In general, the results were as expected.

The Effect of Dietary Fat and Tocopherol on Lipolysis and Oxidation in Turkey Meat Stored at Different Temperatures

“…Increased tocopherol intake enhanced tissue tocopherol levels, also as expected (Crawford et al,, 1975;Marusich et al, 1975;Streiff eta/., 1977).…”

“…Feeding different dietary fats affects the composition of triglycerides and, to less extent, that of phospholipids in turkeys (Neudoerffer and Lea, 1967;Salmon, 1976;Webb et al, 1973), and this influenced the organoleptic and storage characteristics of the meat (Webb et al, 1973;Crawford et al, 1975).…”

“…High dietary tocopherol has been shown to increase tissue tocopherol levels, to retard the onset of rancidity in frozen turkey meat (Crawford et al, 1975), and to attenuate the increase in TBA values on storage (Marusich et al, 1975).…”

Lipids in monogastric animal meat

“…However, the peroxydation of polyunsaturated fatty acids can be a problem. Historically, it contributed strongly to the taste of fish oil [9] and it is still responsible for excessive dripping losses of unfrozen products [39]. In practice, 200 mg of vitamin E per kg feed are necessary for at least 4 weeks before slaughtering to optimise the vitamin content of muscles and to minimise lipid peroxydations [32,39].…”

Flavor and aroma problems and their measurement in meat, poultry and fish products

“…chicken and turkey) is easily altered by diet, with relatively unsaturated lipids having a marked influence on both the composition and flavor/aroma of the carcasses (Reineccius, 1979). Feeding turkeys highly unsaturated fats in their diets results in meat with a 'fishy' flavor according to Crawford et al (1975), which is not a characteristic of the long chain (C 16-C 1S) fatty acids themselves (Reineccius, 1979). Crawford and Kretsch (1976b) concluded that the 'fishy' flavor is due to an oxidative process that occurs during the cooking process.…”