Improvement of Color and Lipid Stability in Beef Longissimus with Dietary Vitamin E and Vitamin C Dip Treatment

The effects of dietary vitamin E supplementation and vitamin C dip treatment on color and lipid stability in longissimus muscle from Holstein and crossbred beef steers were studied during 16 days of display at 4°C. Dietary vitamin E supplementation retarded metmyoglobin formation of the meat and highly suppressed lipid oxidation compared to the control. Holstein longissimus showed higher metmyoglobin formation than crossbred beef longissimus. Dip treatment with a vitamin C solution was effective in maintaining stability of beef color and lipid.     

Vitamin E Supplementation of Holstein Steer Diets Improves Sirloin Steak Color

Colorimetric measurements were recorded for sirloin steaks from control and vitamin E-supplemented (370 I.U./animal/day) Holstein steers. Chroma and Hunter ‘a’ values of steaks from the supplemented group were significantly greater (P&0.01) on days 2, 4, 6, and 8 of 4°C storage. Color difference (ΔE) between the two treatment groups increased from days 0 to 6 and decreased between days 6 and 8.     

Vitamins E and C Improve Pigment and Lipid Stability in Ground Beef

Effect of vitamin E (Vit E), vitamin C (Vit C) and their combination (Vit E + C) on pigment and lipid stability in raw ground beef was studied during 7 days illuminated display at 4°C. Oxidations of pigment and lipid were greatest in controls. Vit E treatment showed moderate pigment and lipid oxidation, and Vit C treatment showed low pigment and lipid oxidation. Vit E+C treatment resulted in the lowest pigment and lipid oxidation.     

Dietary Supplementation of Vitamin E to Feedlot Cattle Affects Beef Retail Display Properties

Beef products from carcasses (n = 20) of cattle fed supplemental vitamin E and beef products from commodity carcasses (n = 20), used as controls, were compared to determine effects of increased vitamin E tissue levels on display appearance of fresh beef held in supermarket and simulated retail conditions. Meat from cattle fed supplemental vitamin E contained higher levels of α-tocopherol (P < 0.05) and, over time, exhibited less lipid oxidation, brighter lean color and lower discoloration. Monitoring supermarkets for discounted retail meats showed increased levels of α-tocopherol in beef extended caselife and decreased the incidence of discounted beef products.     

Dietary Vitamin E Enhances Color and Display Life of Frozen Beef from Holstein Steers

We studied effects of freeze-thaw treatments, storage time, light and film permeability on color of frozen longissimus lumborum (LL) muscle from control and vitamin E supplemented (2100 IU/head/day) Holstein steers. Color changes with time were modeled using an exponential decay equation. Dietary vitamin E supplementation increased color stability of frozen LL samples kept at ?20°C. After 3 mo of dark storage, saturation index and a* for control LL wrapped in polyethylene were 11.4 and 8.8; for supplemented meat, same conditions, they were 19.0 and 17.0, respectively. Illumination and vacuum packaging increased color changes. Predisplay dark storage of 30 days reduced discoloration of supplemented LL. Repeated freeze-thaw cycles caused fading of semimembranosus muscle (SM) and the effect was more pronounced in meat from control animals.     

Pigment Stability Improvement in Beef Steak by Ascorbic Acid Application

The effect on meat color of spreading a vitamin C solution on the surface of fresh beef longjssimus was studied during 16 days of illuminated display at 4°C. The meat treated with 10% vitamin C solution at 0.1 mL solution to 20g meat had lower metmyoglobin and higher oxymyoglobin than the control after 4 days of display. Vitamin C treatment delayed metmyoglobin formation for 3 days compared to the control.     

Kinetics of Pigment Oxidation in Beef from Steers Supplemented with Vitamin E

A model was developed for the mechanistic analysis of pigment oxidation in longissimus lumborum (LL) or gluteus medius (GM) from control and vitamin E supplemented cattle. Metmyoglobin (MetMb) formation presented an induction period which generally increased with supplementation dose and duration, followed by a phase where MetMb accumulated faster than during the induction period. α-tocopherol concentration only affected length of the induction period. Color stable LL had a longer induction period than color labile GM. The model included oxymyoglobin autoxi-dation to MetMb and superoxide anion, and oxidation of oxymyoglobin to MetMb by prooxidants arising from the superoxide anion. α-tocopherol inhibition was interpreted as a competitive reaction between the antioxidant and oxymyoglobin for lipid peroxy radicals.     

Lipid Oxidation and Pigment Changes in Raw Beef

SUMMARY– Two major sources of nonmicrobial deterioration in prepackaged raw meats are the development of off-odors and off-colors. The relationship of these changes to polyunsaturated fatty acid oxidation in the meat was investigated. Lipid oxidation was measured by the thiobarbituric acid test; pigment changes, by reflectance spectrophotometry. Lipid oxidation was found to produce detectable off-odors in raw and subsequently cooked beef. Anaerobic packaging to prevent oxidation of myoglobin and in turn, lipids, appeared to be useful only if packaging (and oxygen removal) could be carried out rapidly and if meat contained sufficient enzyme activity to establish anaerobic conditions quickly and to completely reduce metmyoglobin. Propyl gallate and butylated hydroxyanisole, even under aerobic conditions, offered substantial protection to the fresh meat pigments and at the same time effectively inhibited lipid oxidation.     

Dietary α-Tocopheryl Acetate Contributes to Lipid Stability in Cooked Beef

Lipid oxidation was investigated in cooked gluteus medius from Holstein steers fed diets including four levels of α-tocopheryl acetate (0, 250, 500 and 2,000 mg/steer daily) for 42 or 126 days. Alpha-tocopherol (vitamin E) concentrations increased in fresh and cooked muscle due to level and duration of supplementation (P<0.01). Cooking did not affect α-tocopherol concentration in the muscle. Dietary α-tocopheryl acetate delayed (P<0.01) accumulation of lipid oxidation products in cooked muscle during 6 days of display at 4°. Daily supplementation of 500 mg α-tocopheryl acetate for 126 days resulted in 3.4 μg α-tocopherol/g cooked gluteus medius.     

Dietary α-Tocopheryl Acetate Enhances Beef Quality in Holstein and Beef Breed Steers

The effect of long-term feeding (252 days) of three supplemental levels of α-tocopheryl acetate (actual 0, 360 and 1290 IU/head/day) on meat quality was evaluated in Holstein and beef breed steers. Tissue vitamin E concentrations were increased by each increment of supplementation. The color display life of fresh beef under simulated retail conditions was extended 2 to 5 days by vitamin E and lipid oxidation was markedly reduced. Microbial population was not affected by level of supplementation. No deterioration in sensory quality occurred for steaks from supplemented steers that were displayed until the time steaks from unsupplemented steers discolored.     

Dietary Vitamin E Affects Lipid Oxidation and Total Volatiles of Irradiated Raw Turkey Meat

Breast and leg meat patties, prepared from turkeys fed diets containing 25, 200, 400 or 600 IU of dl-α-tocopheryl acetate (TA) per kg diet, were irradiated at 0 or 2.5 kGy with vacuum or loose packaging. The effects of dietary TA on storage stability and production of volatiles in irradiated raw turkey meat were determined. Dietary TA at > 200 IU/kg decreased lipid oxidation and reduced total volatiles of raw turkey patties after 7-days of storage. However, the antioxidant effects of dietary TA were more notable when the patties were loosely packaged than when vacuum-packaged. Irradiation increased lipid oxidation of raw turkey meats only when loosely packaged but had limited effects on formation of total volatiles after storage at 4°C for 7 days or longer.     

Lipid Stability of Beef Model Systems with Heating and Iron Fractions

Catalytic effects of different temperatures (55, 70, 85, and 100°C) on lipid oxidation were studied in aqueous- and chloroform/methanol-extracted beef model lipid systems containing iron forms inherent in beef (water-extractable, diffusate, nondiffusate, ferritin, myoglobin, hemoglobin), hematin, FeCl₂, or FeCl₃. Heating increased thiobarbituric acid and peroxide values in both systems. All forms of iron catalyzed lipid oxidation in aqueous systems, with greatest oxidation by heme and low molecular weight iron fractions. Oxidation in lipid extracts was not increased by ferritin, FeCl₂, or FeCl₃, but heme iron was the major oxidation catalyst. Lipid stability decreased with addition of any iron forms inherent in beef or with increased heating, which helps understanding of rapid oxidation of meat during refrigerated storage or after cooking.     

Effects of Dietary Oils and α-Tocopherol Supplementation on Lipid Composition and Stability of Broiler Meat

Broilers were fed diets containing oils of varying degrees of unsaturation, namely coconut oil, olive oil, linseed oil and partially hydrogenated soybean oil (HSBO), with and without α-tocopherol supplementation. The different oils significantly (P<0.01) affected the fatty acid composition of the neutral lipids and, to a lesser extent, the fatty acid composition of the phopholipids. Fatty acid composition, in turn, influenced the oxidative stability of the meat during refrigerated and frozen storage. Meat from broilers fed olive oil or coconut oil was consistently more stable than meat from the linseed oil group. Dietary supplementation with α-tocopherol significantly (P<0.01) improved the oxidative stability of the dark and white broiler meat during refrigerated and frozen storage compared to meat from the broilers fed HSBO.     

Effect of Antioxidants on Lipid Stability in Restructured Beef Steaks

Two natural antioxidant formulations–containing mixed tocopherols, ascorbyl palmitate and citric acid–and TBHQ were evaluated in restructured beef steaks formulated to contain 18% fat and 0.75% NaCl. Lipid oxidation was monitored over 12 months of frozen storage. TBHQ significantly (p < 0.05) lowered TBA numbers in raw and freshly cooked samples and in samples that were cooked and held 4 hr at 4°C. Natural antioxidants provided significant (p <0.05) protection in freshly cooked meat and were as effective as TBHQ in retarding lipid oxidation. Sensory evaluation and GC quantitation of hexanal were also used to monitor oxidation but the correlation between the three methods was not significant.     

Response of Cows Consuming Adequate Selenium to Vitamin E and Selenium Supplementation Prepartum

A 2-yr study of 195 parturitions was to evaluate the prepartum need for supplemental vitamin E and selenium by cows consuming diets that contained ample amounts of selenium (.1 to 2.0 ppm selenium). One-half of the cows were injected with 68 IU vitamin E and 5 mg selenium per 45.4 kg body weight approximately 21 days prepartum. Incidences of retained placenta and calving difficulty were similar for treated and control cows. There was a lower incidence of retained placenta (7.5%) for cows that calved during fall, whereas incidence was greater than 20% in cows that calved during the rest of the year. Serum vitamin E and selenium concentrations in treated cows doubled within a day after injection, then declined to concentrations typical of untreated cows within 8 and 3 days postinjection, respectively. Serum carotene, vitamin A, and vitamin E concentrations were similar for treated and control cows and were elevated in cows that calved during the summer and fall, possibly because cows dry during the grazing season were pastured. However, discriminant analysis of 21-day prepartum serum data indicated that serum concentrations of carotene, vitamins A or E, or selenium would not predict accurately the retention of the placenta. Colostrum and 4-day milk from treated and control cows contained similar amounts of vitamin E and selenium.     

Lipid Oxidation in Cooked Pork as Affected by Vitamin E, Cooking and Storage Conditions

The individual and combined effects of muscle vitamin E level, cooking conditions (duration, temperature and rate) and packaging on lipid oxidation in refrigerated cooked pork were examined. Oxidative stability following cooking was higher in pork with a higher vitamin E level (p<0.01), cooked at a lower cooking temperature (p<0.01), cooked for a shorter time (p<0.01), cooked at a faster cooking rate (p<0.05) or stored in vacuum packs (p<0.01). Significant two-way and three-way interactions were observed between the effects of muscle vitamin E level, cooking conditions and packaging on lipid oxidation. Adopting more than one of these approaches to minimize lipid oxidation was more effective than adopting a single approach.     

Effect of Dietary Vitamin E on Immune Responses of Calves

The effect of vitamin E on humoral and cell-mediated immune responses in calves was determined, and plasma vitamin E and immunological status of calves under normal herd management were studied. Twelve newborn calves were fed skimmed colostrum for 2 days and thereafter skimmed milk plus vitamin E-stripped lard and emulsifying agents. Six calves each orally received 0, and six each orally received 1 g of DL-α-tocopherol acetate daily. Rations were supplemented with trace minerals and vitamins A and D. Twenty calves were fed colostrum for 3 days and thereafter milk and dry feed. At 6 wk, mean plasma vitamin E concentrations (μg/100 ml) for groups were 71, 639, and 155, respectively; and mean serum glutamic oxalacetic transaminase concentrations (IU/liter) were 320, 61, and 43, respectively. Mean serum immunoglobulins concentrations (mg/100 ml) were: Gl, 1079, 1168, and 1315; G2, 488, 562, and 432; A, 37, 53, and 85; M, 151, 118, and 110. Mean lymphocyte stimulation indexes were 76, 220, and 152, respectively. At 6 wk there were large but nonsignificant differences in mean indexes among groups.     

Effects of Dietary Oils and α-Tocopherol Supplementation on Membranal Lipid Oxidation in Broiler Meat

The effects of different dietary oils and α-tocopherol on the fatty acid composition of mitochondrial and microsomal lipids of broiler muscle and their lability to NADPH-induced peroxidation were investigated. Fatty acid composition of both neutral lipids and phospholipids of mitochondria and microsomes was influenced by dietary oil composition. Supplementation of the diet with α-tocopherol only appeared to increase the α-tocophcrol concentration in the microsomal membranes in the dark meat. The rate of NADPH-induced lipid peroxidation in microsomes and mitochondria was dependent primarily on the fatty acid composition of the membrane lipids, and, to a lesser extent, on the α-tocopherol content.     

In Vitro Binding of Vitamin E to Selected Dietary Fiber Sources

An in vitro method was used to assess interaction between whole fiber (WF) sources and vitamin E under simulated physiological conditions (pH 2, pH 7, pH 2–7; bile salt 5–15 mM; 37°C). Dose-response and binding characteristics (via Scatchard analysis) were examined. Binding of vitamin E by lupin and gum were higher (p≤0.05) at pH 2 and pH 7 than at the sequential treatment. Oat bran, treated at pH 7 or sequentially, showed increased (p≤0.05) binding of vitamin E as fiber level increased (25 - 100 mg). Scatchard plots revealed two specific noninteracting binding sites for sugarbeet and barley bran. Affinities (K_d) and capacities (n) were compared among fibers. Affinities for vitamin E were: sugarbeet>oat>lupin>barley>gum. Capacities were: barley > gum > lupin > sugarbeet > oat. Vitamin E binding to DF is complex, multifactorial, and not due to a single mechanism.