Search PubMed⌕ Search

Biomedical subjects

P J Sheehy

Publications and source records attributed to P J Sheehy.

8 recordsLinked to original sources
PubMed1997

Tissue content of alpha-tocopherol and oxidative stability of broilers receiving dietary alpha-tocopheryl acetate supplement for various periods pre-slaughter.

1. The effects of dietary alpha-tocopheryl acetate on the alpha-tocopherol status of chicken plasma and tissues were investigated. The rate of iron-ascorbate-induced lipid peroxidation was also studied. 2. One hundred and forty four chicks were divided into 6 groups: one control group was fed a basal diet of 30 mg alpha-tocopheryl acetate/kg food for the duration of the trial. A supplemental diet of 200 mg alpha-tocopheryl acetate was fed to each of the other 5 groups for 1,2,3,4 or 5 weeks prior to slaughter. 3. Supplementation resulted in an increase in alpha-tocopherol in plasma and all tissues examined. Saturation levels of alpha-tocopherol were observed in plasma after 1 week of feeding and in tissues within 3 to 4 weeks of feeding. 4. Supplementation with alpha-tocopheryl acetate for up to 4 weeks pre-slaughter resulted in significant reductions in susceptibility to induced lipid peroxidation. 5. Overall, the results show that feeding 200 mg alpha-tocopheryl acetate/kg food to chicks for at least 4 weeks prior to slaughter is necessary to optimise muscle content and stability against lipid peroxidation.

Abattoirs↗
PubMed1996

Oxidative stability and alpha-tocopherol retention in turkey burgers during refrigerated and frozen storage as influenced by dietary alpha-tocopheryl acetate.

1. The effect of vitamin E (alpha-tocopheryl acetate) in turkey diets on the oxidative stability of raw and cooked turkey burgers and on the retention of alpha-tocopherol during refrigerated (4 degrees C) or frozen (-20 degrees C) storage was investigated. One hundred and two, one-day-old T-8s turkey poults were divided at random into 3 groups of 34 animals each and fed on either a basal diet (normal commercial turkey diet) supplemented with 20 mg alpha-tocopheryl acetate/kg (control) or fed an alpha-tocopherol supplemented diet containing 300 (E300) or 600 (E600) mg alpha-tocopheryl acetate/kg for 21 weeks. 2. Dietary supplementation with alpha-tocopheryl acetate significantly reduced TBARS numbers in both raw and cooked burgers during refrigerated and frozen storage. 3. The mean values of alpha-tocopherol in raw and cooked burgers stored at 4 degrees C did not change during storage. 4. In the case of both raw and cooked samples stored at -20 degrees C, the alpha-tocopherol values decreased from 5.67 to 3.54 and from 3.56 to 2.30 micrograms/g in the raw burgers from turkeys from the E600 and E300 treatments, respectively, after 4 months storage. The values decreased from 5.60 to 2.88 and from 3.29 to 1.85 micrograms/g in cooked burgers from turkeys from the E600 and E300 treatments, respectively, after 5 months storage.

Animals↗
PubMed1994

Consumption of thermally-oxidized sunflower oil by chicks reduces alpha-tocopherol status and increases susceptibility of tissues to lipid oxidation.

The effect of heated sunflower oil consumption on alpha-tocopherol status, fatty acid composition and oxidative stability of chicken tissues was investigated. Chicks were fed on diets containing (g/kg): fresh sunflower oil (FSO) 40, heated sunflower oil (HSO) 40 or heated sunflower oil (40) supplemented with alpha-tocopheryl acetate (HSE) to a similar alpha-tocopherol concentration as the FSO diet. Concentrations of alpha-tocopherol in tissues of chicks fed on HSO and HSE were significantly lower than those of chicks fed on FSO. Significant correlations were observed between plasma alpha-tocopherol concentration and the alpha-tocopherol concentrations of other tissues (r > or = 0.67, P < 0.005) and between log plasma alpha-tocopherol and plasma thiobarbituric acid-reacting substances (TBARS) concentrations (r -0.851, P < 0.001). The concentrations of TBARS in tissues of chicks fed on the various diets were generally very similar before stimulation of peroxidation with Fe-ascorbate. Susceptibility of tissues to Fe-ascorbate-induced lipid peroxidation was increased by feeding HSO. Supplementation with alpha-tocopheryl acetate reduced susceptibility to lipid oxidation to varying degrees, depending on the tissue. The results suggest that chronic ingestion of oxidized lipids may compromise free-radical-scavenging activity in vivo by depleting alpha-tocopherol in the gastrointestinal tract, or possibly in plasma and other tissues.

Animals↗
PubMed1993

Influence of heated vegetable oils and alpha-tocopheryl acetate supplementation on alpha-tocopherol, fatty acids and lipid peroxidation in chicken muscle.

1. Chicks were fed on diets containing fresh, heated or alpha-tocopheryl acetate-supplemented heated vegetable oils. The effects on alpha-tocopherol status, and on the fatty acid composition and oxidative stability of thigh and breast muscle were determined. 2. Plasma alpha-tocopherol was significantly correlated with alpha-tocopherol concentrations in thigh and breast muscle. 3. The fatty acid profiles of muscle lipids reflected dietary fatty acid composition. 4. The consumption of heated sunflower and linseed oils reduced alpha-tocopherol status, altered fatty acid composition of muscle lipids and increased susceptibility of muscle to lipid oxidation. 5. Supplementation of diets containing heated oils with alpha-tocopheryl acetate resulted in some alleviation of these effects. 6. The results indicate that caution should be exercised in the use of thermally oxidised oils in poultry diets if undesirable changes in composition and oxidative stability of carcase lipids are to be avoided.

Animals↗
PubMed1993

Vitamin E.

Explore the source record for details and available documents.

Animals↗
PubMed1991

Influence of dietary alpha-tocopherol on tocopherol concentrations in chick tissues.

1. The effect of feeding alpha-tocopherol (5 to 180 micrograms/g diet) for 24 days on the concentrations of alpha-tocopherol in various chicken tissues was investigated. 2. Tissue alpha-tocopherol concentrations responded to dietary intake in the order: heart congruent to lung greater than liver greater than thigh muscle greater than brain, and in all cases the relationship between the concentrations of dietary and tissue alpha-tocopherol was highly significant (0.997 less than or equal to r less than or equal to 1). 3. Plasma alpha-tocopherol concentration appears to be a good index (r greater than or equal to 0.910, P less than 0.001) of alpha-tocopherol status of lung, liver and heart.

Animals↗