Levels Of Α-tocopheryl Acetate Research Articles

Effects of vitamin E on color stability and palatability of strip loin steaks from cattle fed distillers grains

The objective of this study was to determine the effect of preslaughter antioxidant supplementation to cattle fed wet distillers grains on carcass yield and quality grade, and on the color stability and consumer acceptability of steaks. Two hundred five crossbred steers were fed 35% wet distillers grains with the supplementation of 4 different levels of α-tocopheryl acetate: 0, 125, 250, and 500 IU•animal(-1)•d(-1) for 97 d. Chuck rolls (n = 69) and strip loins (n = 185) were collected and processed at 4 and 7 d postslaughter, respectively. Chucks were ground and separated into 0.23-kg samples. Strip loins were faced and cut into 2.54-cm steaks and packaged in a polyvinyl chloride overwrapped (PVC) package, a vacuum package, or modified atmosphere packages (MAP) for further color, α-tocopherol, objective tenderness, palatability, and proximate analysis. Color was measured objectively using a HunterLab Miniscan XE spectrophotometer (HunterLab Associates Inc., Reston, VA) and subjectively by a trained color panel, and a consumer panel was used to indicate which treatments affected retail acceptability and purchase decisions. Warner-Bratzler shear force measurements were used for objective tenderness, and a trained panel assessed subjective palatability characteristics. Instrumental color measurements revealed little difference for ground beef in both PVC and MAP packages, but diets with 500 and 250 IU•animal(-1)•d(-1) of vitamin E had a longer (P < 0.05) retention of redness and yellowness in steaks as compared with steaks from animals receiving less vitamin E. Subjective color evaluation for strip steaks indicated that greater vitamin E was more likely (P < 0.05) to maintain color stability, overall acceptability, and consumer purchase preference while decreasing percentage of discoloration. No significant differences (P > 0.10) were observed for objective tenderness and sensory attributes of strip steaks, and no differences (P > 0.10) were observed in protein, fat, and moisture percentages of ground beef. Lipid oxidation analysis indicated that steaks packaged in PVC for 7 d and MAP for 1, 3, and 7 d, and ground beef packaged in MAP and PVC for 0 and 7 d of retail display required greater inclusion of vitamin E (500 and 250 IU•animal(-1)•d(-1)) to remain below the 2.28 mg of malonaldehyde/kg threshold. Ultimately, 500 IU•animal(-1)•d(-1) of vitamin E should be supplemented to cattle fed wet distillers grain-based diets when products are packaged in MAP to maximize retail shelf life.

Distribution of α-tocopherol stereoisomers in liver and thigh of chickens

The effect of supplementation with different levels of all-rac-alpha-tocopheryl acetate and the inclusion of different dietary contents of PUFA on the deposition of alpha-tocopherol stereoisomers in liver and thigh of chickens was evaluated. Ninety-six 1-d-old Ross female broiler chickens were randomly distributed into eight experimental treatments (three replicates each) resulting from four levels of alpha-tocopheryl acetate without supplementation and supplemented with 100, 200 and 400 mg alpha-tocopheryl acetate/kg and two levels of dietary PUFA (15 and 61 g/kg). The feeds supplemented with alpha-tocopheryl acetate contained a similar proportion of each stereoisomer. The diets without alpha-tocopheryl acetate had the following alpha-tocopherol stereoisomers (%): RRR 35.1, RRS 24.5, RSR 25.3, RSS 13.9 and total 2S forms 1.3. Consumption of different levels of alpha-tocopheryl acetate did not lead to statistical differences in alpha-tocopherol stereoisomer proportion in the liver and thigh. In general, the stereoisomer profiles in the tissues studied were similar, responding to the stereoisomer profile of the diet. Both tissues preferentially accumulated 2R stereoisomer (69-100 %). However, when alpha-tocopheryl acetate was used the discrimination was not specific for the RRR alpha-tocopherol form. Furthermore, the 2R:2S ratio had a tendency to increase as the polyunsaturation level of the diet increased.

Effects of n-3 Polyunsaturated Fatty Acids-enriched Diet Supplemented with Different Levels of α-Tocopherol on Lipid Metabolism in Laying Tsaiya Ducks

The objective of this experiment was to determine the effects of n-3 polyunsaturated fatty acids (n-3 PUFAs)-enriched diet supplemented with different levels of α-tocopherol on the activities of hepatic lipogenic-related enzymes and the contents of liver and plasma lipid fractions in laying Tsaiya ducks. A total of 180 30-wk-old laying Tsaiya ducks, at the beginning of peak production, were allotted into 6 treatments with 3 replicates each. Ducks were fed one of the 6 experimental diets, containing 4% tallow (control), and 4% fish oil supplemented with graded levels of α-tocopheryl acetate (α-tocopherol) at 0, 100, 200, 300 and 400 mg/kg, respectively, for 6 wks. Feed and water were supplied ad libitum throughout the experimental period. The results indicated that the n-3 PUFAs- enriched diet supplemented with different levels of α-tocopherol did not affect (p>0.05) egg weight, feed intake, body weight change or liver and abdominal fat weights. Egg production, egg mass and feed efficiency significantly (p<0.05) improved as dietary α-tocopherol levels increased. The activities of hepatic lipogenic-related enzymes including acetyl-CoA carboxylase (EC 6. 2. 1. 3; ACC), glucose-6- phosphate dehydrogenase (EC 1. 1. 1. 49; G-6-PDH), ATP-citrate cleavage enzyme (EC 4. 1. 3. 8; CCE), NADP-malate dehydrogenase (EC 1.1.1.40; NADP-MDH) and fatty acid synthetase (FAS) were higher (p<0.05) in birds fed with the tallow diet than in those fed with fish oil diets and increased with increasing dietary α-tocopherol levels. None of the dietary treatments significantly affected the contents of triglyceride and total cholesterol in the liver, or total cholesterol, phospholipid and total lipid in the plasma. However, the contents of phospholipid and total lipid in the liver, and triglyceride in the plasma increased as dietary α-tocopherol levels increased. Increasing dietary α-tocopherol levels decreased the non-esterified fatty acid (NEFA) content in the plasma and trended to decrease the cholesterol contents in the egg yolk. The lipid metabolism of laying Tsaiya ducks was influenced not only by the dietary fat but also by the supplementation levels of α-tocopherol. (Asian-Aust. J. Anim. Sci. 2004. Vol 17, No. 11 : 1562-1569)

Fillet shelf-life of Atlantic halibut Hippoglossus hippoglossus L. fed elevated levels of α -tocopheryl acetate

Fish fillet quality may be influenced by the antioxidant level in preslaughter diet. Thus, the effects of dietary α-tocopheryl acetate supplementation and feeding time on the flesh quality of farmed Atlantic halibut Hippoglossus hippoglossus L. were investigated. Halibut of mean initial weight of 312 ± 12.3 g were divided into two groups and fed commercial diets, supplemented with different levels of α-tocopheryl acetate at the dietary inclusion levels of 189 and 613 mg kg−1 diet. Fish were sampled after 6,9,12 and 24 weeks. Over the experimental period, they reached a final mean weight of 1320 ± 108.4 g. Tissue α-tocopherol of fillet and liver was significantly affected by the levels of α-tocopheryl acetate given with the diets (P < 0.001). In storage on ice, fillets of fish fed the diets high in α-tocopheryl acetate exhibited significantly lower (P < 0.001) levels of lipid oxidation. The colour of fillets in all groups deteriorated slightly, but diet did not affect this process. Halibut fed the supplemented diets for longer periods were better protected against lipid oxidation (P < 0.001) and colour deterioration (P < 0.01) than those fed for shorter periods. However, after 9 days of storage, lipid oxidation levels were still extremely low [< 0.6 µg malondialdehyde (MDA) g−1 fillet], even in fillets of fish fed the low α-tocopheryl acetate diet for a short period preslaughter. Different slaughtering methods tested at the end of the trial showed that percussive stunning can delay the onset of rigor mortis by 8–12 h compared with bleeding of the fish. These results suggest that halibut fillets have enhanced shelf-life stability even at low doses of dietary α-tocopheryl acetate, and that other factors in the antioxidant defence mechanisms of the species might play a major role in the prevention of lipid oxidation.

Slaughtering method and dietary α -tocopheryl acetate supplementation affect rigor mortis and fillet shelf-life of turbot Scophthalmus maximus L.

The effects of dietary α-tocopheryl acetate supplementation and different slaughtering methods were investigated on the flesh quality of farmed market-size turbot Scophthalmus maximus (L). Turbot were divided into three groups and fed commercial diets, supplemented with different levels of α-tocopheryl acetate at the following dietary inclusion levels: 72 (100), 547 (500), 969 (1000) (mg of α-tocopheryl acetate kg−1 diet, analytical values with diet codes in brackets). After 5 months, fish (mean weight 1056 ± 19.7 g) from each dietary treatment were sampled, applying three different slaughtering methods: (A) bleeding in ice water; (B) thermal shock, no bleeding; (C) percussion followed by bleeding in ice water. The time course of rigor mortis was evaluated, using pH, rigor index and mechanical compression tests. The results showed that the three parameters corresponded very well. Percussive stunning resulted in higher initial post-mortem pH (P < 0.01) and a significantly delayed onset of rigor mortis (P < 0.05). Diet significantly affected shelf-life, with fillets from fish fed diets 500 and 1000 having lower TBARS (thiobarbituric acid reactive substances) numbers from day 2 (P < 0.001) and less colour deterioration from day 7 of storage on ice onwards (P < 0.05). These results suggest that an increase in dietary α-tocopheryl acetate before slaughter as well as careful selection of the slaughtering method may greatly enhance the flesh quality of market-size turbot.

Astaxanthin deposition in fillets of Atlantic salmon Salmo salar L. fed two dietary levels of astaxanthin in combination with three levels of α-tocopheryl acetate

The influence of alpha-tocopheryl acetate (alpha-TOAc) on plasma concentration and fillet deposition of dietary astaxanthin was investigated in Atlantic salmon Salmo salar L. The diets were added 30 or 50 mg kg(-1) astaxanthin, and 200, 400 or 800 mg kg(-1) alpha-TOAc at each astaxanthin level. Improved flesh deposition of astaxanthin by 8-14% was achieved for fish fed diets with 30 and 50 mg kg(-1) astaxanthin, respectively, by the dietary addition of 800 compared with 200 mg kg(-1) alpha-TOAc. These results were supported by CIE[1976]L*a*b* tristimulus redness measurements (a* value). Plasma astaxanthin concentration mirrored the muscle astaxanthin concentration in the groups of fish fed a diet containing 30 mg kg(-1) astaxanthin. The salmon fed a high astaxanthin and low alpha-TOAc diet had the highest plasma concentration of idoxanthin (P < 0.05). Astaxanthin retention was significantly higher (P < 0.001) in salmon fed 30 mg kg(-1) astaxanthin than in those fed 50 mg kg(-1) astaxanthin, but was not significantly affected by dietary alpha-TOAc. Liver weight, body weight, specific growth rate, feed/gain ratio and mortalities were not affected by dietary alpha-TOAc levels. In conclusion, the dietary addition of alpha-TOAc appears to increase astaxanthin fillet deposition in salmonids and may reduce the demand for astaxanthin supplementation. The effect was rather small and requires verification.

Fatty Acid Profile and α-Tocopherol Content of Porcine Muscle During Oxidative Changes

Polyunsaturated fatty acids (PUFA) especially n-3 PUFA are important components of healthy human diets but these fatty acids are very susceptible to oxidation. Lipid peroxidation has been implicated as contributor to many pathological processes in humans (Byers, 1993). It is well established that tissue vitamin E (α-tocopherol; AT) protects lipid against peroxidation in vivo and in vitro. During lipid oxidation, vitamin E supplies are depleted and there are health benefits from higher intakes of the vitamin. In this study, changes in fatty acid composition and AT content of pig muscle during-oxidation were examined.Twenty four Large White x Landrace pigs were individually fed, from 50 to 90 kg LW, either a control (CD) diet (containing palm oil) or a diet based on full-fat rapeseed (FFR; 250 g/kg) (diet FRD) with varying levels of α-tocopheryl acetate (ATA) (0, 200 and 500 mg/kg diet for FRD0, FRD200 and FRD500 respectively). Diets were isonitrogenous and isocaloric.