Simultaneous determination of Vitamin E homologs in chicken meat by liquid chromatography with fluorescence detection

Impact of chronic heat stress on behavior, oxidative status and meat quality traits of fast-growing broiler chickens

This research aimed to investigate, through a multifactorial approach, the relationship among some in-vivo parameters (i.e., behavior and blood traits) in broilers exposed to chronic HS, and their implications on proximate composition, technological properties, and oxidative stability of breast meat. A total of 300 Ross 308 male chickens were exposed, from 35 to 41 days of age, to either thermoneutral conditions (TNT group: 20°C; six replicates of 25 birds/each) or elevated ambient temperature (HS group: 24 h/d at 30°C; six replicates of 25 birds/each). In order to deal with thermal stress, HS chickens firstly varied the frequency of some behaviors that are normally expressed also in physiological conditions (i.e., increasing "drinking" and decreasing "feeding") and then exhibited a behavioral pattern finalized at dissipating heat, primarily represented by "roosting," "panting" and "elevating wings." Such modifications become evident when the temperature reached 25°C, while the behavioral frequencies tended to stabilize at 27°C with no further substantial changes over the 6 days of thermal challenge. The multifactorial approach highlighted that these behavioral changes were associated with oxidative and inflammatory status as indicated by lower blood γ-tocopherol and higher carbonyls level (0.38 vs. 0.18 nmol/mL, and 2.39 vs. 7.19 nmol/mg proteins, respectively for TNT and HS; p < 0.001). HS affected breast meat quality by reducing the moisture:protein ratio (3.17 vs. 3.01, respectively for TNT and HS; p < 0.05) as well as the muscular acidification (ultimate pH = 5.81 vs. 6.00, respectively; p < 0.01), resulting in meat with higher holding capacity and tenderness. HS conditions reduced thiobarbituric acid reactive substances (TBARS) concentration in the breast meat while increased protein oxidation. Overall results evidenced a dynamic response of broiler chickens to HS exposure that induced behavioral and physiological modifications strictly linked to alterations of blood parameters and meat quality characteristics.

Intake of nutrients (polyunsaturated fatty acids, tocols, and carotenes) and storage efficiency in different slow-growing chickens genotypes reared in extensive systems

An extensive rearing system (ERS) for poultry requires an outdoor run, which enhances the foraging activity of chickens. Slow-growing (SG) strains are more adapted to ERS than fast-growing (FG); and generally, have higher levels of bioactive compounds in their meat. The aim of this paper was to assess the storage efficiency of n-3 and n-6 polyunsaturated fatty acids (PUFA), tocols and carotenes in the meat of seven commercial SG genotypes (SG1-7). One hundred SG chicks/strain of both sexes were included and their walking activity (High- or Low-W) was classified: SG1-4, HW comprised more than 10% of the time budget, and SG5-7, less than 10% (LW). Chickens were reared in pens (4 pens/strain) with indoor (0.10 m2/bird) and outdoor (4 m2/bird) areas, and they were fed the same diet ad libitum (starter feed for 1-21 d, grower feed from 22 d to slaughter at 81 d). The chickens were weighed weekly; feed consumption and grass intake were also estimated. At 81 days of age, 32 chickens/genotype were selected on the basis of the average weight (1:1, M:F) and slaughtered. The breast, thigh and drumstick meat were excised from 30 carcasses/genotype, sampled and stored at -20°C until analysis. Nutrients (e.g., n-3, n-6, carotenes and tocols) of feed, grass and meat were analyzed. The storage efficiency of nutrients was estimated as the ratio between the amount deposited in the body muscles (OUT) and the dietary intake (feed and grass, IN). The genotype affected chickens foraging behavior and the intake of nutrients. For SG1, SG2 and SG3, more than 50% of the intake of n-3 came from grass, whereas in the other genotypes, less than 20%. Accordingly, chickens that foraged more showed better meat nutritional profiles (less fat, more n-3 and antioxidants), which, in ERS, was ascribed to grass ingestion. However, the storage efficiency of nutrients into meat was inversely correlated with the grass intake: strains with higher grass intake (SG1, SG2, and SG3) had lower storage rates. Several hypotheses were proposed to explain these trends.

How the kinetic behavior of organic chickens affects productive performance and blood and meat oxidative status: a study of six poultry genotypes

The aim of this study was to analyze the relationship between the kinetic behavior, carcass characteristics, oxidative status (blood and meat), and meat fatty acid profiles of 6 organically reared slower growing chicken genotypes (SrG). One hundred male chickens of 6 SrG were used: Ranger Classic (RC), Ranger Gold (RG), Rowan Ranger (RR), RedJA (RJ), CY Gen 5 JA87 (CY), and M22 × JA87 (M). Twenty chickens/genotype were selected to analyze behavior, while, 15 individuals were slaughtered and different traits were analyzed in the blood and drumstick meat. The variables were grouped into different principal components: kinetic activity (PC1, with explorative attitude as the highest score), productive performance (PC2, carcass and head/feet yields), blood (PC3, carbonyls, and TBARS) and meat (PC6, thiols, and TBARS) markers, technological traits (PC4, pH, and color), proximate meat composition (PCA5, moisture, lipids, protein, and ash), fatty acid profile, and nutritional indexes (PC7, IP, and PUFAn-3). Uni- and bivariate analyses showed a strong positive association between kinetic behaviors and blood and meat oxidation and a medium positive association with fatty acid profile and nutritional indexes, whereas a negative association was found between productive performance loads and the technological traits of meat. Generalized linear models showed that all PCs were influenced by genotype. In particular, CY and M resulted as less active genotypes; conversely, RR showed more kinetic activity, whereas RJ, RG, and RC exhibited intermediate levels of activity. Cluster analysis of kinetic behavior and blood or meat oxidative status highlighted 2 groups: nonwalking (NW: CY and M) and walking (W: RC, RG, RR, and RJ) animals. However, in the W group, another was visualized, constituted by genotypes with high kinetic activity resulting in the worst oxidative balance (Walking not trained-genotypes, Wnt: RR and RJ). The present results confirmed that the kinetic behavior of SrG genotypes is negatively correlated with productive performance. Furthermore, a significant association between kinetic behavior and blood (positively correlated) or meat (negatively correlated) oxidative status was noted. Such differences are mainly due to the intrinsic response of the genotypes used (i.e., training-walking capacity).

Fatty acid profile, oxidative status, and content of volatile organic compounds in raw and cooked meat of different chicken strains

Chicken meat is rich in unsaturated fatty acids. Therefore, it is more susceptible to lipid oxidation and production of volatile organic compounds (VOC). In this study, we evaluated the fatty acids, antioxidants, and VOC profiles of raw and cooked meat samples derived from 4 strains of chicken differing in their growth rates, which were as follows: slow-growing (SG, Leghorn), medium-growing (MG, Hubbard and Naked Neck), and fast-growing (FG, Ross). The VOC profile of meat was measured using proton-transfer reaction–mass spectrometry (PTR–MS). The VOC were identified using PTR–time of flight-MS (PTR-ToF-MS). The data were analyzed using both univariate and multivariate models. Twenty main VOC were identified, which were classified into the following chemical categories: aldehydes, alkadienes, alkenes, furans, amides, alcohols, and other compounds. Our results revealed that the chicken genotype and the method of cooking strongly influenced the VOC profile of the meat. Identifying the relationships between these traits allowed us to highlight the trade-off of the main substrates such as n-3 and n-6 polyunsaturated fatty acids (PUFA), protective substances (antioxidants), and degradation products (VOC) of the poultry meat produced during cooking. The extent of VOC production and n-3 loss was found to be higher for the SG genotype. Reduction of n-6 was higher in MG, whereas small losses in antioxidants and PUFA were observed in the FG genotype, consequently, resulting in the lowest production of VOC. The SG and MG are genotypes more active from a kinetic point of view respect to the FG ones. For this reason, in the FG genotypes, the antioxidants are less involved in the oxidative stress induced by the movement; thus, they were available to protect the lipid of the meat during the cooking process. These results suggested that the use of SG and MG genotypes requires a specific dietary protocol (i.e., increasing the antioxidants content) to counteract the lipid oxidations in all the phases: in vivo, postmortem, and during/after cooking.

Effect of trub and/or linseed dietary supplementation on in vivo oxidative status and some quality traits of rabbit meat

The objective of this study was to compare the effect of the dietary beer trub, alone or in combination with linseed, on meat quality, oxidative status and cholesterol content of rabbit. Eighty New Zealand White rabbits were divided at weaning (30 d) into four dietary groups: control (C) fed a standard diet, trub (T, 2% of lyophilized trub), linseed (L, 3% of extruded linseed), and trub-linseed in combination (TL, 2% of lyophilized trub and 3% of extruded linseed). At slaughtering (80 d) the oxidative parameters of blood and quality of Longissimus thoracis et lumborum were analysed. The in vivo lipid oxidation was similar in the supplemental groups, whereas it was higher in T, L and TL meat compared to C. Trub supplementation in rabbit diets slightly affected the fatty acid profile (MUFA) and worsened the oxidative status of meat, and its inclusion in combination with linseed did not counteract the oxidative instability induced by the higher PUFA content.

The antioxidant effectiveness of liquorice (Glycyrrhiza glabra L.) extract administered as dietary supplementation and/or as a burger additive in rabbit meat

The present research studied the effect of liquorice extract (in feed and/or directly in burgers) on the shelf-life of rabbit meat. Before weaning, 28 individually caged rabbit does with their litters were divided in two dietary groups: Control, receiving a commercial diet, and Liquorice, receiving the Control diet supplemented with 6 g liquorice extract/kg (L). At 12 weeks of age, 15 fattened rabbits/treatment (one rabbit/cage) were slaughtered and their hindlegs dissected. Hindleg meat was trimmed, individually minced and divided into two parts: one of them was mixed with 0.25% (w/w) L. Storage time significantly reduced the amount of polyunsaturated fatty acids in the burger, to a different magnitude depending on the unsaturation level, experimental group and storage time. The α-tocopherol content showed higher levels during storage in the burgers from the Liquorice group. Also TBARs values showed a significant positive effect of dietary liquorice and a progressive increase at days 3 and 6 of storage.

Use of Selenium-enriched olive leaves in the feed of growing rabbits: Effect on oxidative status, mineral profile and Selenium speciation of Longissimus dorsi meat

In the present study the use of Selenium-fortified olive leaves as potential dietary source of Se in rabbit nutrition was evaluated. Sixty New Zealand White rabbits (35 days of age) were randomly assigned to the following dietary treatments: standard diet (C), and C supplemented with either 10% olive leaves (OL) or 10% Selenium-fortified olive leaves (SeOL; 100 mg/L of foliar spray sodium selenate solution). At 70 days of age, 10 rabbits per group were slaughtered and the oxidative status, mineral profile and Selenium speciation of Longissimus dorsi meat was analyzed. Meat of the SeOL group exhibited better oxidative status (lower TBARS, higher GPx and α-tocopherol values) and a 5-fold higher Se content compared to that of the other treatments. The main Se form was SeMet (7-fold higher in the SeOL group), followed by SeCys₂. The present trial demonstrates the possibility of using agro-industrial by-products as ingredients in rabbit feeds, thereby enriching meat bioactive compound content.

Effect of diet and packaging system on the oxidative status and polyunsaturated fatty acid content of rabbit meat during retail display

The aim of this study was to evaluate the combined effect of two dietary lipid sources (sunflower vs. linseed oil) and three packaging methods (PVC film - BAG vs. modified atmosphere CO₂ 20% + 80% O₂ - MAP vs. and vacuum - VAC) on the oxidative status and polyunsaturated fatty acid content of rabbit loins (Longissimus thoracis et lumborum muscle), at days 1, 4 and 10 of simulated retail display. The diet, storage time and packaging method affected the oxidative status of rabbit meat under retail display. As expected, storage time, independently on the other factors, significantly reduced the antioxidant content of loin meat. Accordingly, TBARs values significantly increased during storage, as well as the dietary supplementation of linseed. The fatty acid profile of the fresh loin closely respected that of the diets. At day 10, oxidative status and fatty acid profile of MAP samples could be yet considered optimal.

Square wave voltammetry at carbon paste electrode modified with surfactant for alpha tocopheryl acetate determination in cosmetics

The aim of this study was describe electrochemical properties of a carbon paste electrode (CPE) bulk modified with 30% (w/w) surfactant sodium dodecyl sulphate (CPE/SDS) and demonstrates its application in the determination of α‑tocopheryl acetate (α‑TAc), known as vitamin E acetate, in selected cosmetic products, especially body creams. In addition to anionic SDS, cationic hexadecylpyridinium chloride monohydrate (CPC) was also tested as possible modifier. It was found that selection of surfactant type and its content significantly affect an electrical conductivity and mechanical stability of these heterogeneous electroanalytical sensors in pure organic solvents. Under this study, it was found that CPC is a totally inappropriate mediator due to very high backgroundcurrent. Together with other lipophilic vitamins characterized by antioxidant activity (dominantly retionoids), this completely synthetic substance is widely used as significant cosmetic additive due its preservative properties. Monitoring of its content in cosmetic products is usually performed by high‑performance liquid chromatography (HPLC) with UV detection. This standard analytical protocol is always burdened with the complex and time‑consuming preparation of the sample before analysis. For that reason, robust and simple electroanalytical method based on anodic oxidation of the α‑TAc at CPE/SDS by square wave voltammetry (SWV) performed in pure organic electrolyte (99.8% acetonitrile containing 0.1 mol·L‑1 LiClO4) was developed. Moreover, simple dissolution of sample in supporting electrolyte using ultrasonic bath and subsequent filtering through a stacked filter included all the necessary procedures for sample preparation. The linear range from 0.1 to 1.2 mmol·L‑1and limit of detection 37 µmol·L‑1 were found at pulse amplitude 10 mV and frequency 10 Hz as optimum. In analysis of selected cosmetics, the developed electroanalytical method was not validated using comparison with standard HPLC. At least, the recovery was verified by analysis of model sample and value 95.8% was calculated.

Nitrite Embedded Vacuum Packaging Improves Retail Color and Oxidative Stability of Bison Steaks and Patties

Bison meat is prone to rapid discoloration under traditional aerobic retail packaging conditions. The aim of this study was to determine if the color stability of bison steaks and burger patties could be improved through packaging meat with a vacuum-sealed film containing embedded sodium nitrite. Bison bulls (n = 40) were slaughtered and the longissimus lumborum (LL) and rhomboideus (RH) were removed. Following a postmortem aging period of 6, 13, or 20 d steaks were obtained from the LL. RH muscles aged 6 d were ground (85:15 lean to fat) and formed into 140 g patties. One steak and two burger patties from each carcass side were placed into either a polystyrene tray overwrapped with oxygen permeable polyvinyl chloride film (CONT) or a polyethylene tray vacuum sealed with film coated in sodium nitrite (113 mg × m–2; NIT); meat was placed under simulated retail conditions for 4 d. A 3-way interaction was observed between packaging type, whole muscle aging and time in retail display for objective (L*, Chroma, and Hue) and subjective (lean color score and proportion of surface discoloration) color measures from steaks (P < 0.0001). The CONT packaged meat showed an increased area of discoloration and in metmyoglobin after 4 d in retail display (P < 0.0001); NIT meats did not show a higher area of discoloration or metmyoglobin after retail display. Additionally, NIT packaged steaks and burger patties lightened (higher L*) and became redder over the course of the retail display period. Thiobarbituric acid reactive substances (products of lipid peroxidation) did not increase in NIT packaged burger patties after 4 d under retail conditions, however, there was a significant increase observed for CONT packaged burger patties (P < 0.0001). NIT packaging appears to effectively improve the color stability of bison meat under retail conditions, making this packaging strategy well suited to address the issue of rapid discoloration.

Fattening rabbits in mobile arks: effect of housing system on in vivo oxidative status and meat quality

<p>The aim of this trial was to study the effect of an alternative housing system on the oxidative status and meat quality of fattening rabbits. From May to June 2014, 60 rabbits of 35 d of age were reared in Mobile Arks (MA) placed on alfalfa grass and frequently moved for 40 d. To assess the health status of animals, blood samples were collected at slaughter in MA and in conventional cages (C). Meat quality parameters were also evaluated. Concerning the <em>in vivo </em>oxidative status, ark-reared rabbits showed higher thiobarbituric reactive substances values than C ones, probably for the higher motor activity due to the larger living area. The lipid percentage of <em>Longissimus lumborum </em>muscle was lower (1.22 <em>vs. </em>1.48%) in the ark group. There were no significant differences in the muscle pH, colour, water holding capacity and cooking loss. Given the higher intake of grass, rich in vitamins, carotenes, polyphenols and polyunsaturated fatty acids, the antioxidant content of meat was higher in ark-reared rabbits (7.42 <em>vs. </em>6.82 µg/g of retinol, 719.2 <em>vs. </em>683.3 ng/g of α-tocopherol, respectively). Even the fatty acid profile of MA rabbits reflected the higher intake of essential fatty acids from grass and the n-3 long chain polyunsaturated fatty acids (arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid) were almost doubled. Our study suggested that the fattening of rabbits in ark system could be a possible alternative system to improve the meat quality of rabbits.</p><p><strong><br /></strong></p>

Carcass traits and meat quality of growing rabbits in pens with and without different multilevel platforms

The aim of this trial was to determine the effect of the presence of wire or plastic mesh elevated platforms on carcass traits and meat quality characteristics, with particular attention to the oxidative status of growing rabbits. A total of 174 five-week old rabbits were randomly divided into 3 groups with 2 replications (6 pens; 29 rabbits/pen): pens without platforms (NoP) with a stocking density of 16 rabbits/m2 and pens with wire-mesh platforms (WP) or plastic-mesh platforms (PP) that were placed on 2 levels, with a stocking density of 16 rabbits/m2 on the floor or 9.14 rabbits/m2 when the platform were included. At 84 d rabbits were slaughtered. The slaughter traits and Longissimus lumborum (LL) physical and chemical compositition were not affected by treatments. Rabbits from the PP group showed the highest retinol and γ-tocotrienol content on LL muscle, whereas the NoP ones showed a higher α-tocotrienol and α-tocopherol level. The absence of platforms led to decreased (P&lt;0.001) thiobarbituric acid-reactive substances values and induced an improvement in n-3 polyunsaturated fatty acids. Levels of linoleic, linolenic and docosahexaenoic acids were equal to those of the WP group (23.45, 3.75, 0.64% in NoP and 22.6, 4.14, 0.53% in WP, respectively) but higher than in PP rabbits (20.86, 3.05, 0.45%, respectively). It can be concluded that the pens with elevated platforms provide greater possibilities for movement, which is beneficial from the viewpoint of animal welfare. However, this greater activity influences the oxidative status of the meat, decreasing the antioxidant content and worsening the lipid oxidation of rabbit meat.

Transfer of bioactive compounds from pasture to meat in organic free-range chickens

The aim of this study was to analyze the transfer of bioactive compounds from the pasture to the body and meat of organic free-range chickens and to verify the effect of these compounds on the oxidative processes of the meat. Starting at 21 d of age, 100 male naked-neck birds were divided into two homogeneous groups: an indoor group (0.12 m(2)/bird) and an outdoor group (0.12 m(2)/bird indoor and 10 m(2)/bird of forage paddock). At slaughter (81 d of age), blood samples were collected, and the carcasses were stored for 24 h at 4°C (20 birds/group). The grass samples had higher values of carotenoids, tocopherols, and flavonoids respect to standard feed (based on dry matter comparison). The polyunsaturated fatty acid ( PUFA: ) content was also greater in grass, especially the n-3 series (so named because its first double bond occurs after the third carbon atom counting from the methyl at the end of the molecule). The antioxidant profile of the grass improved the antioxidant status of the crop and gizzard contents in the outdoor chickens. The higher antioxidant intake resulted in a higher plasma concentration of antioxidants in outdoor birds; thiobarbituric acid reactive substances ( TBARS: ) and the antioxidant capacity of the plasma were also better in the outdoor than the indoor group. The meat of the outdoor birds had higher levels of antioxidants, mainly due to the higher amount of tocopherols and tocotrienols. Despite the higher antioxidant protection in the drumstick of the outdoor group, the TBARs value was greater, probably due to the kinetic activity of birds, the higher percentage of PUFAs, and the peroxidability index. In conclusion, grazing improved the nutritional value of the meat (PUFA n-3 and the ratio between n-6 and n-3 PUFA) with a minor negative effect on the oxidative stability. Suitable strategies to reduce such negative effects (e.g., reduction of kinetic activity in the last days of rearing) should be studied.

A review of characterization of tocotrienols from plant oils and foods

Tocotrienols, members of the vitamin E family, are natural compounds found in a number of vegetable oils, wheat germ, barley and certain types of nuts and grains. Vegetable oils provide the best sources of these vitamin E forms, particularly palm oil and rice bran oil contain higher amounts of tocotrienols. Other sources of tocotrienols include grape fruit seed oil, oats, hazelnuts, maize, olive oil, buckthorn berry, rye, flax seed oil, poppy seed oil and sunflower oil. Tocotrienols are of four types, viz. alpha (α), beta (β), gamma (γ) and delta (δ). Unlike tocopherols, tocotrienols are unsaturated and possess an isoprenoid side chain. A number of researchers have developed methods for the extraction, analysis, identification and quantification of different types of vitamin E compounds. This article constitutes an in-depth review of the chemistry and extraction of the unsaturated vitamin E derivatives, tocotrienols, from various sources using different methods. This review article lists the different techniques that are used in the characterization and purification of tocotrienols such as soxhlet and solid-liquid extractions, saponification method, chromatography (thin layer, column chromatography, gas chromatography, supercritical fluid, high performance), capillary electrochromatography and mass spectrometry. Some of the methods described were able to identify one form or type while others could analyse all the analogues of tocotrienol molecules. Hence, this article will be helpful in understanding the various methods used in the characterization of this lesser known vitamin E variant.

Tocopherol and tocotrienol homologs in parenteral lipid emulsions

Parenteral lipid emulsions, which are made of oils from plant and fish sources, contain different types of tocopherols and tocotrienols (vitamin E homologs). The amount and types of vitamin E homologs in various lipid emulsions vary considerably and are not completely known. The objective of this analysis was to develop a quantitative method to determine levels of all vitamin E homologs in various lipid emulsions. An HPLC system was used to measure vitamin E homologs using a Pinnacle DB Silica normal phase column and an isocratic, n-hexane:1,4 dioxane (98:2) mobile phase. An optimized protocol was used to report vitamin E homolog concentrations in soybean oil-based (Intralipid®, Ivelip®, Lipofundin® N, Liposyn® III, and Liposyn® II), medium- and long-chain fatty acid-based (Lipofundin®, MCT and Structolipid®), olive oil-based (ClinOleic®), and fish oil-based (Omegaven®) and mixture of these oils-based (SMOFlipid®, Lipidem®) commercial parenteral lipid emulsions. Total content of all vitamin E homologs varied greatly between different emulsions, ranging from 57.9 to 383.9 µg/mL. Tocopherols (α, β, γ, δ) were the predominant vitamin E homologs for all emulsions, with tocotrienol content < 0.3%. In all of the soybean emulsions, except for Lipofundin® N, the predominant vitamin E homolog was γ-tocopherol, which ranged from 57–156 µg/mL. ClinOleic® predominantly contained α-tocopherol (32 µg/mL), whereas α-tocopherol content in Omegaven® was higher than most of the other lipid emulsions (230 µg/mL).

The effects of husbandry system on the grass intake and egg nutritive characteristics of laying hens

BACKGROUND

The aim of this study was to determine the effect of husbandry system and season on the grass intake and egg quality in laying hens considering that characteristics of organic eggs obtained in a system with no grass in the external area are similar conventional ones.

RESULTS

Three hundred and sixty Ancona hens were randomly assigned to three groups: a control group (C), with the hens kept in cages under standard housing conditions; the organic group (O), with the hens kept under an organic production system (4 m² per hen) and the organic-plus group (OP), with the hens maintained under organic conditions but with a larger grass paddock availability (10 m² per hen). The estimated intake of forage, carotenoids and flavonoids of the OP hens was very high as the amounts deposited in eggs, mainly in the spring season. The fatty acid composition of the yolk was significantly affected by pasture. The OP eggs showed lower concentrations of polyunsaturated fatty acids (PUFA) n-6 and a higher percentage of PUFA n-3.

CONCLUSIONS

The results showed that the grass intake was largely affected by the husbandry system and highlighted the seasonal effect of grass availability on the nutritional quality of eggs produced in organic systems.

Effect of dietary supplementation of Spirulina (Arthrospira platensis) and Thyme (Thymus vulgaris) on rabbit meat appearance, oxidative stability and fatty acid profile during retail display

The objective of this study was to evaluate the effect of Spirulina and Thyme supplementation on rabbit meat during retail display. At weaning 294 rabbits were allocated to 7 different treatments (42 rabbits/treatment). Rabbits of the control group (C) received a diet without any supplementation throughout the experiment (5-11 weeks of age). The other groups were fed diets containing 5% Spirulina (S), 3% Thyme (T) or both supplements (ST) for the whole trial (5-11 weeks; treatments S, T and ST), or for a part of the growing period (8-11 weeks; treatments C-S, C-T and C-ST). Colour parameters, pH, water holding capacity and drip loss were determined on fresh and stored Longissimus dorsi muscle of 5 rabbits/treatment. Spirulina- and Thyme-supplemented diets had a significant effect on redness and yellowness of Longissimus dorsi. Drip loss was significantly reduced in C-T and T groups that also showed the highest content of α-tocopherol and n-3 fatty acids content and the lower lipid oxidation.

Use of palm-oil by-products in chicken and rabbit feeds: effect on the fatty acid and tocol composition of meat, liver and plasma

This study was undertaken in the framework of a larger European project dealing with the characterization of fat co- and by-products from the food chain, available for feed uses. In this study, we compare the effects, on the fatty acid (FA) and tocol composition of chicken and rabbit tissues, of the addition to feeds of a palm fatty acid distillate, very low in trans fatty acids (TFA), and two levels of the corresponding hydrogenated by-product, containing intermediate and high levels of TFA. Thus, the experimental design included three treatments, formulated for each species, containing the three levels of TFA defined above. Obviously, due to the use of hydrogenated fats, the levels of saturated fatty acids (SFA) show clear differences between the three dietary treatments. The results show that diets high in TFA (76 g/kg fat) compared with those low in TFA (4.4 g/kg fat) led to a lower content of tocopherols and tocotrienols in tissues, although these differences were not always statistically significant, and show a different pattern for rabbit and chicken. The TFA content in meat, liver and plasma increased from low-to-high TFA feeds in both chicken and rabbit. However, the transfer ratios from feed were not proportional to the TFA levels in feeds, reflecting certain differences according to the animal species. Moreover, feeds containing fats higher in TFA induced significant changes in tissue SFA, monounsaturated fatty acids and polyunsaturated fatty acids composition, but different patterns can be described for chicken and rabbit and for each type of tissue.

Effect of flaxseed and forage type on carcass and meat quality of finishing cull cows

Hernández-Calva, L. M., He, M., Juárez, M., Aalhus, J. L., Dugan, M. E. R. and McAllister, T. A. 2011. Effect of flaxseed and forage type on carcass and meat quality of finishing cull cows. Can. J. Anim. Sci. 91: 613–622. Sixty-two cull cows were fed one of four diets in a 2×2 factorial arrangement, consisting of barley silage or grass hay with or without flaxseed to influence fatty acid composition. After slaughter, carcass grade, meat quality and sensory data were collected. Silage increased live (P=0.002) and carcass (P=0.001) weights of the cows as compared with hay. Muscle width (P=0.013) and score (P=0.010) and rib-eye area (P=0.002) were enhanced when silage was included in the diet, whereas supplementation with flaxseed increased (P=0.003) grade fat depth by 29%. Most subjective and objective retail evaluation traits in steaks from the left longissimus thoracis and ground meat were negatively affected (P<0.05) by the length of the retail display time. Moreover, dietary hay increased (P=0.015) the lean colour values in steaks and ground beef, which was corroborated by lower L* (P=0.009) and higher hue (P=0.010) in steaks and lower L* (P=0.049), chroma (P=0.005) in ground beef as compared with cows fed silage. A significant interaction between forage type and flax inclusion for thiobarbituric acid reactive substances (TBARS) (P=0.050) was observed. After sensory evaluation, steaks from cows fed silage had an increase (P=0.030) in beef flavour intensity when compared with cows fed hay, whereas inclusion of flaxseed in the diet decreased (P<0.001) beef flavour intensity in steaks from cows fed both forage sources. Sensory evaluation of ground beef found that hay-fed cows with flaxseed supplementation had decreased (P=0.03) beef flavour intensity, while the same effect was not observed in ground beef from cows fed silage with flaxseed. Results from this study show that inclusion of flaxseed in the diet reduced off-flavours in steak, but for ground beef this response depended on the source of forage in the diet.

Oxidative stability in grinds from omega-3 enhanced pork

Juárez, M., Dugan, M. E. R., Larsen, I. L., Thacker, R., Rolland, D. C. and Aalhus, J. L. 2011. Oxidative stability in grinds from omega-3 enhanced pork. Can. J. Anim. Sci. 91: 623–634. In order to investigate the effect of enhancing n-3 fatty acid levels in carcasses on the retail and sensory characteristics of pork grinds, as well as the ability of increasing dietary levels of vitamin E to stabilize the increase in PUFA levels from flaxseed supplementation, 81 pigs were used in a 3×3 factorial experiment. Dietary treatments included three lengths of time (0, 3 and 6 wk) of flaxseed supplementation and three levels of vitamin E (40, 200 and 400 mg kg feed−1). α-Tocopherol tissue levels increased with dietary vitamin E supplementation (P<0.001), and fat softness (P=0.018) and total PUFA and n-3 fatty acids (P<0.001) increased with flaxseed supplementation. Most other animal performance, carcass and lean pork quality traits were not affected (P>0.05) by dietary treatments. In ground pork, the increase in TBARS after 6 d in retail was lower (P<0.001) with increasing dietary vitamin E levels. However, vitamin E had no effect (P>0.05) on the higher (P<0.001) TBARS levels observed in grinds from flaxseed fed pigs. The dietary addition of flaxseed negatively modified (P<0.05) all the sensory attributes of both cooked and reheated products. Increasing the fat content of the grinds up to 30% seemed to counteract (P>0.05) the negative effects of feeding flaxseed for 3 wk. Feeding vitamin E was not able to prevent negative effects (P<0.05) observed during retail display in grinds with either increasing fat content or higher n-3 fatty acids from dietary flaxseed. However, increasing dietary vitamin E only showed a protective effect (P<0.05) on retail appearance after long periods of ageing.

Method for simultaneous analysis of eight vitamin E isomers in various foods by high performance liquid chromatography and fluorescence detection

The objective of this study was to optimize a method to investigate the occurrence and to quantify the full isomeric composition of vitamin E (α-, β-, γ- and δ-tocopherols and tocotrienols) in 6 vegetables (raw and cooked), 3 herbs/spices, raw and cooked eggs, vegetable oils (canola, olive and soybean), flaxseed and sorghum (flour and seeds) and soy (flour) by HPLC with fluorescence detection. Different conditions of extraction and analysis were tested. The optimized method consisted of direct extraction with solvent (hexane:ethyl acetate, 85:15, v/v). For analysis normal phase column was used with mobile phase consisting of hexane:isopropanol:acetic acid (98.9:0.6:0.5) with isocratic elution and fluorescence detection. Excellent separation of all isomers was obtained along with adequate quantification in the foods analyzed. Recovery rates of standards ranged from 91.3 to 99.4%. The linearity range for each isomer varied from 2.5 to 137.5 ng/mL (R² greater than 0.995 in all cases). Detection limits ranged from 21.0 to 48.0 ng/mL for tocopherols and from 56.0 to 67.0 ng/mL for tocotrienols, while quantification limits ranged from 105.0 to 240.0 ng/mL for tocopherols and from 280.0 to 335.0 ng/mL for tocotrienols. The optimized method was considered simple, fast and reliable, and also preserved vitamin E isomers when compared to validated methods involving saponification.

Determination of Vitamin E in Coffee Beans by HPLC Using a Micro-extraction Method

This work reports a solid—liquid micro-extraction method for vitamin E quantification in coffee beans (before and after roasting) with normal-phase HPLC/diode-array/fluorescence detection. The compounds were extracted after protein precipitation and overnight maceration (4°C) in n-hexane, in the presence of butylated hydroxytoluene, using tocol as internal standard. The extraction method precision was inferior to 5% with mean recoveries near 100%. Chromatographic resolution from co-eluting interferences was achieved within 8 min with a 75 × 3.0 mm (3 μm) silica column by using an isocratic elution with n-hexane/ 1,4-dioxane (98 : 2), at a flow rate of 0.7 mL/min. The diode-array detector was a valuable tool in the detection of co-eluting interferences and quantification was based on the fluorescence measurements. Only two vitamers, a- and b-tocopherol, were confirmed and quantified, being the latter generally the major compound in both arabica and robusta coffees. The present analytical method proved to be simple, sensitive, reproducible, accurate, allowing a fast quantification with low organic solvent consumption.

Assessment of the levels of degradation in fat co- and byproducts for feed uses and their relationships with some lipid composition parameters

This paper discusses the levels of degradation of some co- and byproducts of the food chain intended for feed uses. As the first part of a research project, "Feeding Fats Safety", financed by the sixth Framework Programme-EC, a total of 123 samples were collected from 10 European countries, corresponding to fat co- and byproducts such as animal fats, fish oils, acid oils from refining, recycled cooking oils, and other. Several composition and degradation parameters (moisture, acid value, diacylglycerols and monoacylglycerols, peroxides, secondary oxidation products, polymers of triacylglycerols, fatty acid composition, tocopherols, and tocotrienols) were evaluated. These findings led to the conclusion that some fat by- and coproducts, such as fish oils, lecithins, and acid oils, show poor, nonstandardized quality and that production processes need to be greatly improved. Conclusions are also put forward about the applicability and utility of each analytical parameter for characterization and quality control.

Vitamin E delta-tocotrienol levels in tumor and pancreatic tissue of mice after oral administration

Tocotrienols are natural vitamin E compounds that are known to have a neuroprotective effect at nanomolar concentration and anti-carcinogenic effect at micromolar concentration. In this report, we investigated the pharmacokinetics, tumor and pancreatic tissue levels, and toxicity of delta-tocotrienol in mice because of its anti-tumor activity against pancreatic cancer. Following a single oral administration of delta-tocotrienol at 100 mg/kg, the peak plasma concentration (C(max)) was 57 +/- 5 micromol/l, the time required to reach peak plasma concentration (T(max)) was 2 h and plasma half-life (t(1/2)) was 3.5 h. The delta-tocotrienol was cleared from plasma and liver within 24 h, but delayed from the pancreas. When mice were fed delta-tocotrienol for 6 weeks, the concentration in tumor tissue was 41 +/- 3.5 nmol/g. This concentration was observed with the oral dose (100 mg/kg) of delta-tocotrienol which inhibited tumor growth by 80% in our previous studies. Interestingly, delta-tocotrienol was 10-fold more concentrated in the pancreas than in the tumor. We observed no toxicity due to delta-tocotrienol as mice gained normal weight with no histopathological changes in tissues. Our data suggest that bioactive levels of delta-tocotrienol can be achieved in the pancreas following oral administration and supports its clinical investigation in pancreatic cancer.