The inhibitory potential of feed supplementation with rosemary and/or α-tocopheryl acetate on microbial growth and lipid oxidation of turkey breast during refrigerated storage

Twenty-four 12-week-old female turkeys divided into four equal groups were fed a basal diet (CONT) or basal diet supplemented with 300 mg α-tocopheryl acetate/kg (TOC), or 5 g rosemary/kg (ROS5), or 10 g rosemary/kg (ROS10), for 4 weeks. Following slaughter, fillets from breast were stored at 4 °C in the dark for 12 days, and lipid oxidation was assessed on the basis of the malondialdehyde formed, whereas microbial growth on the basis of total viable counts (TVC), lactic acid bacteria (LAB), Enterobacteriaceae (ENB) and psychrotrophic (PSY) bacteria. Results showed that incorporation of dried rosemary in turkey diets delayed lipid oxidation in raw breast meat during refrigerated storage. Dietary rosemary at the level of 1 g/100 g was significantly (P<0.05) more effective in delaying lipid oxidation compared to 0.5 g/100 g but inferior to the dietary supplementation of 300 mg α-tocopheryl acetate/kg. TVC, LAB, ENB and PSY bacterial counts were all significantly increased (P<0.05) in breast samples of all groups throughout the refrigerated storage. The TOC and CONT groups presented TVC, LAB, ENB and PSY counts that did not differ (P>0.05) among each other, during the whole storage period. However, the rosemary-supplemented groups presented bacterial counts that were significantly lower (P<0.05) than the CONT and TOC groups, at day 2 of storage period and thereafter. During this period, the ROS5 group presented TVC, LAB, ENB and PSY counts that were significantly higher (P<0.05) than the ROS10 group.     

Effects of protein level and fat/oil on emulsion stability,texture, microstructure and color of meat batters

Beef meat batters formulated with increasing protein level (10–15%) and containing 25% beef fat were compared to batters prepared with 25% canola oil. Emulsion stability of the canola oil treatments was higher (less separation during cooking) at the 10–13% protein level compared to the beef fat treatments. However, above 13% protein this was reversed and the canola oil treatments showed high fat and liquid separation, which did not occur at all in the beef fat treatments. This indicates differences in stabilization of fat versus oil in such meat emulsions. Hardness of the cooked meat batters showed significantly (P < 0.05) higher values when the protein level was raised, and was higher in canola oil than in beef fat meat emulsions at similar protein levels. Products’ chewiness were higher in the canola oil treatments compared to the beef fat emulsions. Lightness decreased and redness increased in canola oil batters as the protein level was raised. The micrographs revealed the formation of larger fat globules in the beef fat emulsions compared to the canola oil meat emulsions. The canola oil treatment with 14% protein started to show fat globule coalescence, which could be related to the reduced emulsion stability.     

The effect of corn distiller's dried grains with solubles, ractopamine, and conjugated linoleic acid on the carcass performance, meat quality, and shelf-life characteristics of fresh pork following three different storage methods

The objective of this study was to evaluate dietary corn distiller's dried grains with solubles (DDGS), ractopamine hydrochloride (RAC), and conjugated linoleic acid (CLA) on growth performance, carcass and fat quality, and shelf-life of fresh pork from finishing pigs. Barrows (n = 72) were fed one of eight treatments consisting of two diet sources (corn-soy and corn-soy + 20% DDGS), two levels of RAC (0 and 7.4 ppm), and two levels of CLA (0 and 0.6%) for 28 days. Loins were portioned (n = 3) into one of three storage conditions (fresh, cold, frozen); each followed with seven days of retail display. Feeding RAC improved ADG and G:F (P < 0.05), whereas DDGS decreased belly fat firmness (P < 0.05). Dietary DDGS increased total polyunsaturated fatty acids in jowl and belly samples and increased Iodine Value (IV) (P < 0.05), but addition of CLA decreased IV. Dietary DDGS, RAC, or CLA had minimal impact on pork quality following varied storage methods.     

Effect of dietary olive leaves and/or α-tocopheryl acetate supplementation on microbial growth and lipid oxidation of turkey breast fillets during refrigerated storage

Thirty turkeys were allocated to five groups of six birds each. One group that served as control was fed a basal diet, while the others were fed diets supplemented with olive leaves at 5 or 10 g/kg, or α-tocopheryl acetate at 150 or 300 mg/kg. Following slaughter, fillets from breast were stored at 4 °C in the dark for 12 days, and lipid oxidation and microbial growth were assessed. Results showed that the incorporation of olive leaves in turkey diets increased (P < 0.05) the oxidative stability of raw breast fillets during refrigerated storage. Dietary olive leaves at 10 g/kg were more effective (P < 0.05) in inhibiting lipid oxidation compared to 5 g/kg, but inferior to the supplementation of 300 mg α-tocopheryl acetate/kg. In turn, α-tocopheryl acetate supplementation at 150 mg/kg was equal to olive leaves at 5 g/kg but inferior to olive leaves at 10 g/kg. Total viable counts, lactic acid bacteria, Enterobacteriaceae and psychrotrophic bacteria counts were all increased (P < 0.05) in breast fillets of all groups throughout the refrigerated storage. Diet supplementation with α-tocopheryl acetate had no effect on the bacterial counts recorded in the control group, but diet supplementation with olive leaves resulted in decrease (P < 0.05) of all bacterial counts at day 2 of storage and thereafter; during this period, olive leaves at the level of 10 g/kg were more effective in inhibiting bacterial growth compared to the level of 5 g/kg.     

Inhibition of lipid oxidation in long-term frozen stored chicken meat by dietary oregano essential oil and α-tocopheryl acetate supplementation

The antioxidative effect of dietary oregano essential oil and α-tocopheryl acetate supplementation on susceptibility of chicken breast and thigh muscle meat to lipid oxidation during frozen storage at −20 °C for 9 months was examined. Day-old chickens (n=80) were randomly divided into four groups, and fed a basal diet containing 30 mg α-tocopheryl acetate kg⁻¹ feed as control, or basal diet plus 200 mg α-tocopheryl acetate kg⁻¹ feed, or basal diet plus 50 or 100 mg oregano essential oil kg⁻¹ for 38 days prior to slaughter. Lipid oxidation was assessed by monitoring malondialdehyde (MDA) formation with third-order derivative spectrophotometry, after zero and 7 days of refrigerated storage at 4 °C following 1, 3, 6 and 9 months of frozen storage. Results clearly demonstrated that all dietary treatments had a major impact on the oxidative stability of broiler meat. Dietary oregano essential oil supplementation at the level of 100 mg kg¹ feed was significantly (P⩽0.05) more effective in reducing lipid oxidation compared with the level of 50 mg oregano essential oil kg⁻¹ feed and control, but less effective (P⩽0.05) compared with α-tocopheryl acetate supplementation. Thigh muscle was found to be more susceptible to oxidation compared to breast muscle, although the former contained α-tocopherol at markedly higher levels. Mean α-tocopherol levels in muscle samples decreased during the frozen storage, the decrease being sharper between 1–3 months and 3–6 months of frozen storage for breast and thigh muscle samples, respectively.     

Effect of oil sources and vitamin E levels in the diet on the composition of fatty acids in rooster thigh and chest meat

The aim of this study was to evaluate the inclusion of different oil sources and dietary supplementation with vitamin E on the composition of fatty acids in rooster meat. Two hundred and forty 30‐week‐old White Leghorn roosters were distributed in a completely randomized factorial arrangement of 5 × 2, using five oil sources (sunflower, soybean, canola, linseed and fish) and two levels of antioxidant (30 and 400 mg vitamin E kg^?1 of diet). The intake of fish and canola oil in the diet reduced (P < 0.05) the content of saturated and unsaturated fatty acids in the thigh meat. Amongst the unsaturated fatty acids in the thigh, the fish and canola oil reduced (P < 0.05) the level of ω6 fatty acid, with a consequent decrease in the ratio ω6:ω3. The diet with fish oil increased (P < 0.05) the content of C22:6ω3 in the thigh meat. The use of linseed oil resulted in a significant reduction of the ratio of ω6:ω3 fatty acid in the thigh. The use of soybean oil in the diet increased (P < 0.05) the content of saturated and unsaturated fatty acids in the thigh, specifically in the content of ω6. The inclusion of vitamin E increased the polyunsaturated fatty acids in the chest meat, such as C18:3ω3, C20:5ω3 and C22:6ω3. Copyright © 2004 Society of Chemical Industry     

Oxidative changes of fresh loin from pig,caused by dietary conjugated linoleic acid and monounsaturated fatty acids,during refrigerated storage

Three levels (0%, 1% and 2%) of a conjugated linoleic acid enriched oil (CLA) were combined with two levels of monounsaturated fatty acids (MUFA) (19% and 39% average) for pig feeding. Changes in instrumental colour, lipid oxidation (thiobarbituric acid reactive substances, TBARS) and volatile profile of fresh loin chops, as affected by dietary CLA, MUFA and CLA × MUFA, were studied throughout 7 days of refrigerated storage. Lightness (L∗) evolution was conditioned by dietary CLA, whereas changes in redness (a∗) and yellowness (b∗) were unaffected by dietary supplements. Dietary CLA at 2% led to higher TBARS values of loin chops at day 7 of refrigerated storage (p < 0.05), while MUFA supplementation and CLA × MUFA interaction did not affect lipid oxidation. Dietary CLA, MUFA or CLA × MUFA did not affect most volatile compounds of loin chops after 7 days of storage.     

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.     

The effect of palm oil or canola oil on feedlot performance,plasma and tissue fatty acid profile and meat quality in goats

Twenty-four entire male Kacang kid goats were fed diets containing 3% canola (n = 12) or palm oil (n = 12) supplements for 16 weeks. The goats had an initial live weight of 14.2 ± 1.46 kg and were fed a mixed ration ad libitum (10.4 MJ/ME and 14% crude protein). There was no difference in feedlot performance due to diet. Inclusion of canola oil reduced (P < 0.05) kidney fat weight and increased (P < 0.05) linolenic acid (18:3n − 3) concentration in the blood plasma, m. longissimus lumborum (LL), liver, and kidney. The palm oil diet increased (P < 0.05) myristic (14:0) and palmitic (16:0) acid content in the blood, but this did not alter these fatty acids in the LL muscle. Lipid oxidative substances in the liver and LL from palm oil fed kids were higher (P < 0.05) than those from canola supplemented kids. The incorporation of canola oil into the goats' diet increased muscle omega-3 fatty acid content, but lipid oxidation was lowered in the blood and muscle LL.     

The effects of brined onion extracts on lipid oxidation and sensory quality in refrigerated cooked turkey breast rolls during storage

The effects of brined onion extracts on selected aspects of quality in cooked encased turkey breast rolls were evaluated during refrigerated storage over 7 days. Using the thiobarbituric acid (TBA) assay, a 50% strength juice gave a significant reduction (P < 0.0001) in lipid oxidation in both 100 g and 1 kg rolls relative to controls. Quercetin, the main onion juice antioxidant, was reduced by 65% in freshly cooked 1 kg rolls compared with raw rolls but changed little thereafter in storage. Cook yields were significantly higher for rolls containing added onion extracts than for controls (P < 0.05) but no colour differences were detected using Hunter Lab values (P ? 0.05). A 30-member untrained sensory panel expressed no preference for freshly opened 4 day-stored control or onion extract-supplemented rolls packed in plastic casings but there was a significant preference (P < 0.05) for the onion extract product when 4 mm thick meat slices were stored in air for an additional 24 h.     

Antioxidant activity of Carob fruit extracts in cooked pork meat systems during chilled and frozen storage

The purpose of this study was to evaluate the effect of adding condensed tannins in the form of non-purified (Liposterine^®) or purified (Exxenterol^®) extracts obtained from Carob fruit to prevent lipid cooked pork meat systems from oxidising during chilling and frozen storage. The antioxidant activity of these extracts was compared with that of α-tocopherol. Meat lipid alteration was evaluated as thiobarbituric acid reactive substances content (TBARS) and polar material-related triglyceride compounds followed by high-performance size-exclusion chromatography (HPSEC). TBARS levels were lower (P < 0.05) in samples containing Liposterine (LM), Exxenterol (EM), and α-tocopherol (TM) than in control sample (CM) under chilled storage. TBARS formation was similar (P > 0.05) for LM and EM but lower (P < 0.05) than for TM. Polar material increased several times in all samples, but significantly less in TM and EM than in LM. Thermal oxidation compounds determined by HPSEC were lower (P < 0.05) in EM than in LM or TM. The changes in polar material were proportionally smaller after six months frozen storage than after chilled storage, with Exxenterol displaying the highest antioxidant protection. Therefore Carob fruit extracts can be successfully used to reduce fat alteration in cooked pork meat at chilled and frozen temperatures.     

Dietary CLA alters intramuscular fat and fatty acid composition of pig skeletal muscle and subcutaneous adipose tissue

The present study was conducted to determinate the responsiveness of different levels of dietary conjugated linoleic acid (CLA) on intramuscular fat (IMF) and fatty acid composition of skeletal muscle and fat in pigs fed from 59.5 to 133.5 kg. Forty female Large White × (Large White × Landrace) pigs were used. Four levels (0%, 0.5%, 1% and 2%) of a commercial enriched CLA oil supplementation (60% of CLA isomers, 30% cis-9, trans-11 and 30% trans-10, cis-12) were fed to pigs. Carcass, ham, foreleg and loin weights were recorded. Dietary CLA enrichment increased the loin weight (P < 0.01) and the combined weights of hams + forelegs + loins (P < 0.02). IMF content in Longissimus dorsi was also increased by dietary CLA treatment (P < 0.001) and a linear response was observed. Dietary CLA increased saturated fatty acids (SFA) and decreased monounsaturated fatty acids (MUFA) in muscle and adipose tissue (P < 0.001). Feeding 1% CLA to finishing swine increases IMF in heavy pigs slaughtered at an average weight of 133.5 kg.     

Stability of potassium iodide and omega-3 fatty acids in fortified freshwater fish emulsion sausage

Oxidative stability of emulsion sausages prepared from African walking catfish (AF: Clarias gariepinus) and rohu (RH: Labeo rohita) fortified with three levels of the refined tuna oil (2%, 6%, and 10%) with 150 μg KI/100 g sample and without KI was investigated. The control was prepared using 20% soybean oil and without KI. Samples were vacuum-packed and stored at 4 °C. Iodine content decreased approximately 14% after cooking and remained constant throughout storage. Sausages fortified with tuna oil showed higher level of n-3 (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), but lower level of n-6 fatty acids (P<0.05) than the control. The ratio of n-6 to n-3 fatty acids of all samples decreased with an increase of tuna oil addition and was stable throughout 4 weeks of storage. Degradation of linoleic (LA) and linolenic acid (LNA) mainly occurred in the samples added 2% tuna oil whereas samples fortified with higher tuna oil (6-10%) exhibited higher loss of EPA and DHA. Hydroperoxide (HPV) and thiobarbituric reactive substances (TBARS) values were increased as addition level of tuna oil increased. Textural properties were not affected during storage at 4 °C for up to 4 weeks (P<0.05). Based on lipid stability results, 2% fortification of the refined tuna oil was recommended for emulsion sausage prepared from both species. Addition of 150 μg KI/100 g had no effect on lipid oxidation of fish sausages (P<0.05).     

Growth and carcass fatty acid composition of beef steers fed soybean oil for increasing duration before slaughter

Duration of soybean oil (SBO) supplementation needed to enhance carcass conjugated linoleic acid (CLA) and trans-vaccenic (TVA) content was examined using 96 beef steers (293.6 ± 3.9 kg) fed a 78% corn-based diet supplemented with SBO for 0, 77, 137, or 189 days before slaughter. Duration of SBO supplementation had no effect (P ? 0.15) on animal performance or carcass traits, nor (P ? 0.15), total, total saturated, or total polyunsaturated fatty acids of Longissimus dorsi (LD). Concentrations of CLA in LD were not affected (P ? 0.18) by SBO supplementation. Concentrations of monounsaturated fatty acids (MUFA) decreased linearly (P = 0.03) in LD, whereas TVA increased (P = 0.04) in adipose tissue and tended (P = 0.07) to increase in LD with increasing duration of SBO supplementation. Supplementing SBO to a concentrate-based diet may enhance TVA without impacting CLA, while reducing the MUFA content of lean beef.     

Oxidative and thermal stabilities of genetically modified high oleic sunflower oil

The oxidative and thermal stabilities of genetically modified high oleic sunflower oil (87% oleic acid) were compared with those of regular sunflower (17% oleic acid), soybean, corn, and peanut oils during storage at 55 °C and simulated deep fat frying at 185 °C. Oxidative stability was evaluated by measuring the oxygen content and volatile compounds in the sample bottle headspace and peroxide value. The coefficient variations (CVs) for volatile compound, headspace oxygen, and peroxide value analyses were 2.02%, 1.41%, and 3.18%, respectively. The oxidative stability of high oleic sunflower oil was greater than those of regular sunflower and soybean oil (P < 0.05) and as good as those of corn and peanut oils (P > 0.05). The thermal stabilities of oils during deep fat frying were evaluated by measuring the infrared absorption at 2.9 μm and conjugated diene content. The CV of conjugated diene content was 1.07%. Infrared and conjugated diene results showed that the high oleic sunflower oil had greater thermal stability than had regular sunflower, soybean, corn, and peanut oils (P < 0.05). The genetically modified high oleic sunflower oil, with 5.5% linoleic acid, had better oxidative and thermal stabilities than had the regular sunflower oil with 71.6% linoleic acid.     

Effects of replacing pork back fat with vegetable oils and rice bran fiber on the quality of reduced-fat frankfurters

The effects of substituting olive, grape seed, corn, canola, or soybean oil and rice bran fiber on the chemical composition, cooking characteristics, fatty acid composition, and sensory properties of low-fat frankfurters were investigated. Ten percent of the total fat content of frankfurters with a total fat content of 30% (control) was partially replaced by one of the vegetable oils to reduce the pork fat content by 10%. The moisture and ash content of low-fat frankfurters with vegetable oil and rice bran fiber were all higher than the control (P < 0.05). Low-fat frankfurters had reduced-fat content, energy values, cholesterol and trans-fat levels, and increased pH, cooking yield and TBA values compared to the controls (P < 0.05). Low-fat frankfurters with reduced-fat content plus rice bran fiber had sensory properties similar to control frankfurters containing pork fat.     

Antioxidant and emulsifying properties of potato protein hydrolysate in soybean oil-in-water emulsions

The efficacy of a previously developed antioxidative potato protein hydrolysate (PPH) for the stabilisation of oil droplets and inhibition of lipid oxidation in soybean oil-in-water (O/W) emulsions was investigated. Emulsions (10% lipid, pH 7.0) with PPH-coated oil droplets were less stable than those produced with Tween 20 (P < 0.05). However, the presence of PPH, whether added before or after homogenisation with Tween 20, retarded emulsion oxidation, showing reduced formation of peroxides up to 53.4% and malonaldehyde-equivalent substances up to 70.8% after 7-d storage at 37 °C (P < 0.05), when compared with PPH-free emulsions. In the emulsions stabilised by PPH + Tween 20, 8–15% of PPH was distributed at the interface. Adjustment of the pH from 3 to 7 markedly increased ζ-potential of such emulsions (P < 0.05). Inhibition of lipid oxidation by PPH in soybean O/W emulsions can be attributed to both chemical and physical (shielding) actions.     

Animal performance and fatty acid composition of lambs fed with different vegetable oils

Twenty-seven lambs were used to investigate the effects of the inclusion of 4% hydrogenated palm oil (HPO) or sunflower oil (SFO) in the concentrate on animal performance, carcass and meat quality and fat characteristics and fatty acid composition. Animals (16.2 ± 0.27 kg initial weight) were fed concentrate (Control, HPO or SFO) and barley straw ad libitum and slaughtered at 25 kg. SFO lambs tended to eat less concentrate than HPO animals (P < 0.10). Neither HPO nor SFO affected any of the carcass characteristics studied, meat pH and meat and fat colour (P > 0.05). SFO decreased proportions of C16:0, C18:1 cis-11 and C18:3 (P < 0.05) and increased C18:1 trans (P < 0.001) and C18:2/C18:3 ratio (P < 0.05). Atherogenicity index was lower (P < 0.05) when SFO was included in the concentrate. HPO did not affected and SFO improved fatty acid composition of fattening lambs without affecting animal performance.     

Roselle (Hibiscus sabdariffa L.) and soybean oil effects on quality characteristics of pork patties studied by response surface methodology

Response surface methodology was used to investigate the effect and interactions of processing variables such as roselle extract (0.1–1.3%), soybean oil (5–20%) on physicochemical, textural and sensory properties of cooked pork patties. It was found that reduction in thickness, pH, L* and b* values decreased; however, water-holding capacity, reduction in diameter and a* values increased, respectively, as the amount of roselle increased. Soybean oil addition increased water-holding capacity, reduction in thickness, b* values of the patties. The hardness depended on the roselle and soybean oil added, as its linear effect was negative at p < 0.01. The preference of color, tenderness, juiciness, and overall quality depend on the addition of roselle and soybean oil. The maximum overall quality score (5.42) was observed when 12.5 g of soybean oil and 0.7 g of roselle extract was added. The results of this optimization study would be useful for meat industry that tends to increase the product yield for patties using the optimum levels of ingredients by RSM.     

Effects of dietary conjugated linoleic acid on the growth performance of chickens and ducks for fattening and fatty acid composition of breast meat

The effects of dietary conjugated linoleic acid (CLA) supplementation on feed intake, growth performance, carcass composition and fatty acid composition of meat tissue were investigated in broiler chickens and Pekin ducks. A total of 108 male chickens for fattening and a total of 96 male and 96 female Pekin ducks were allocated to 3 dietary treatments (0.0, 0.1 and 0.2 % CLA) and fed for 35 or 49 days. The results showed that 0.2 % CLA supplementation in the first 3 weeks improved the daily feed intake of the broilers and the feed to gain ratio, but did not significantly influence body weight, weight and the percentage of abdominal and visceral fat as well as the intramuscular fat in breast muscles. In the duck trial, the daily feed intake was significantly higher through the first 3 weeks of male control group and male 2 g CLA group compared with the female control group. The daily weight gain of all male ducks was significantly higher compared to female ducks of all groups and was not influenced by the CLA supplementation. The feed to gain ratio of the 1 g CLA-male ducks was lowest compared to male and female control ducks and 1 and 2 g CLA female ducks. Supplementing diets with CLA modified the fatty acid composition of breast muscle. The proportion of CLA was increased in broiler meat. In duck meat, the proportions of CLA, saturated fatty acids and polyunsaturated fatty acids were increased and monounsaturated fatty acids were decreased.