Higher TBARS Research Articles

The Effects of Replacing Pork Fat with Cold-Pressed Coconut Oil on the Properties of Fresh Sausage

The effects of substituting coconut oil on the chemical composition, microorganism, and sensory properties of fresh sausages were investigated. This experiment evaluated three (0, 10%, 20%) levels of cold-pressed coconut oil (CPCO) and pork fat stored at 3°C for 14 days. The following treatments: 1) control (20% pork fat: 0% CPCO), 2) 0% pork fat: 20% CPCO and 3) 10% pork fat: 10% CPCO were replicated three times. Treatments were analyzed for pH value, % moisture content, % drip loss, lipid stability (thiobarbituric acid-reactive substances TBARS), aerobic plate counts, Escherichia coli, Staphylococcus aureus, and sensory analysis. The initial moisture content of fresh sausage in this experiment ranged from 63.44 to 65.67%. Fresh sausage with 20% CPCO inhibited the growth of aerobic bacteria and obtained the highest TBARS values (4.25 mg MDA/kg) compared to the control treatment. In addition, fresh sausage (10% pork fat and 10% CPCO) decreased the % drip loss, pH value and obtained the highest overall rating (6.45) of sensory testing (n = 75). No E. coli and S. aureus were found in this study for 14 d at 3°C.

Are there differences in lipid peroxidation and immune biomarkers between major depression and bipolar disorder: Effects of melancholia, atypical depression, severity of illness, episode number, suicidal ideation and prior suicide attempts

BackgroundThere is evidence that major depression (MDD) and bipolar disorder (BD) are accompanied by activated immune & oxidative (I&O) pathways. MethodsTo compare I&O biomarkers between MDD and BD we assessed serum levels of thiobarbituric acid reactive substances (TBARS; a lipid peroxidation marker), soluble interleukin-2 receptor (sIL-2R), sIL-6R, IL-α, sIL-1R antagonist (sIL-1RA), tumor necrosis factor receptor 60kDa/80kDa (sTNFR60/R80) in 114 MDD and 133 BD patients, and 50 healthy controls. We computed z-unit weighted indices reflecting the 5 cytokine receptor levels (zCytR), cell-mediated immunity (zCMI) and I&O pathways (zCMI+TBARS). ResultsThere are no significant differences in biomarkers between MDD and BD. BD/MDD with atypical features is characterized by increased sIL-6R and TBARS, whereas melancholia is associated with higher TBARS and lower sTNFR60 levels. Severity of illness, as measured with the Hamilton Depression Rating Scale, is correlated with increased sIL-6R, sTNFR80, TBARS, zCytR and zCMI+TBARS. The number of episodes the year prior to blood sampling is positively associated with sTNFR80, TBARS, zCMI, zCMI+TBARS, while number of hospitalizations is positively associated with sIL-1RA. Prior suicidal attempts are associated with increased sIL-1RA, IL-1α, zCMI, TBARS and zCMI+TBARS, while TBARS is associated with current suicidal ideation. ConclusionsThere are no I&O biomarker differences between MDD and BD. Atypical depression is associated with increased IL-6 trans-signaling and lipid peroxidation. Severity of depression, number of episodes and suicidal attempts are associated with activated I&O pathways. Increased TBARS is the single best predictor of BD/MDD, atypical depression, melancholia and current suicidal ideation.

The -786 T/C polymorphism of NOS3 gene is a susceptibility marker of COPD among Tunisians that correlates with nitric oxide levels and airflow obstruction

ObjectiveThe goal of this study was to examine the role of G894T (rs1799983), -786T/C (rs3918161) and a 27 bp variable number of tandem repeats (VNTR) 4B/4A of NOS3 gene on the risk and severity of COPD. MethodsThe study included 194 controls and 138 COPD patients. NOS3 G894T, -786T/C and 4B/4A variants were determined by PCR analysis based on the banding pattern on gel electrophoresis. Pulmonary function was evaluated using body plethysmography. The levels of nitric oxide, peroxynitrite and lipid peroxides (T-BARS) were determined using spectrophotometric methods. Levels of serum IL-6, TNF-α and TGFβ were determined by ELISA. ResultsIn case-control studies, both G894T and -786T/C variants were associated with COPD risk. A significantly increased risk of COPD was found with the NOS3894T and -786C alleles (OR:1.93, P=0.001; OR:2.05, P=0.001, respectively). No significant impact of the G894T and 4B/4A SNPs was found on COPD severity, while a significant correlation was retrieved between the NOS3 -786T/C variation and advanced stages (OR: 1.89, P=0.009). In addition, COPD patients with the -786CC genotype exhibited lower FEV1% values in comparison to -786TT carriers (48±3.28 vs. 58.06±2.3, P=0.01, respectively). Patients having the -786CC genotype presented lower plasma levels of nitric oxide and higher T-BARS in comparison to -786TT individuals (173.22±13.4 vs. 228.93±16.8, P=0.01; 1.8±0.15 vs. 1.22±0.15, P=0.01, respectively). ConclusionThis study provides the first evidence for the association of G894T, -786T/C variants with COPD risk among Tunisians. The -786T/C variation correlates with enhanced airflow limitation. This finding could be related to altered levels of nitric oxide and enhanced lipid peroxides among patients carrying the -786CC genotype.

Interaction of diet and long ageing period on lipid oxidation and colour stability of lamb meat

Eighty-four crossbred wether and ewe lambs were allocated to four finishing diets. The diets were: Lucerne pasture (n=24), Annual ryegrass with sub clover pasture (n=18), Standard commercial feedlot pellets (n=24) and Annual ryegrass based pasture and commercial feedlot pellets (500g/day/head) (n=18). After 8weeks of feeding the lambs were slaughtered and the m. longissimus (LL) and m. semimembranosus (SM) were vacuum packaged and held chilled for 5 (fresh) or 60 (long aged) days, after which samples of each were displayed for 4days under simulated retail conditions. Irrespective of muscle type the long aged samples exhibited a rapid reduction in redness (a*-values) and R630/580nm ratio values such that consumer acceptable thresholds for both traits were quickly exceeded providing limited shelf life. Long ageing also lead to high TBARS levels measured as MDA mg/kg muscle suggestive of a product likely to exhibit rancidity and off flavours from lipid oxidation.

Effects of Fast Freezing First Then Thaw-Aging on Quality and Chemical Attributes of Beef Muscles

ObjectivesFreezing is an effective preservation method to extend the shelf life of meat products. Despite of the benefits, quality deteriorations associated with freezing, such as decreases in water holding capacity (WHC) and/or oxidative stability have been well documented. Fast freezing is known to enhance the quality of frozen/thawed meat by inducing the formation of intracellular small ice crystal formation, and thus reducing muscle damage. Aging prior to freezing is a common process to improve the quality of the frozen meat. As positive aging impacts can be shown after freezing/thawing, we hypothesized that fast freezing first then thaw-aging would result in equivalent or better meat quality attributes compared to the conventionally aged/frozen beef products. The objective of this study was to evaluate the effect of different freezing rate and aging/freezing sequence on quality and physicochemical attributes of beef loins.Materials and MethodsBoth loin (Longissimus lumborum) and eye of round (Semitendinosus) muscles from 1 side of 10 beef carcasses were obtained at 3d postmortem, cut into 4 sections and vacuum packaged. The sections were randomly assigned to 4 different combinations of aging/freezing- (Aging Only (AO), Slow Freezing then Thaw-Aging (SFTA), Fast Freezing then Thaw-Aging (FFTA), or Aging first then Slow Freezing (ASF). Aging was conducted at 2°C for 2 wk. Frozen samples were stored at –20°C for 3 wk. Fast freezing was conducted using a liquid nitrogen freezing cabinet set at –75°C. Conventional blast freezer set at –20°C was used for slow freezing. Frozen samples were thawed at 2°C until the internal temperature reached –1.5°C. Meat quality measurements such as shear force, WHC by assessing purge/thaw loss, drip loss and cook loss, and color stability were conducted. For display color, steaks were overwrapped with PVC film and displayed for 7d under light, and instrumental and visual color evaluations were performed. Other chemical analyses including 2-thiobarbituric acid reactive substance (TBARS), non-heme iron (NHI) content and histology for muscle micro-structure analysis were performed. All data were analyzed using the PROC MIXED of SAS (SAS Inst. Inc., Cary, NC).ResultsFFTA samples took less than 3 h to reach –20°C of internal temperature, while SFTA samples took almost 3 d. Both FFTA and SFTA samples exhibited a higher total moisture loss (P < 0.05) when compared to the other treatments. No significant difference in shear force was found between the treatments, although the steak samples from FFTA showed numerically lowest shear force values compared to the others (P = 0.12). AO samples maintained the highest a* value during the entire display between the treatments. Rapid increase in discoloration was observed in steak samples from SFTA, followed by FFTA and ASF after 4 d display. Higher TBARS and NHI contents were observed on all frozen/thawed samples compared to non-frozen AO after display (P < 0.05).ConclusionWe found that fast freezing first then thaw-aging did not result in positive impacts on the overall quality characteristics of frozen/thawed meat products. The results also indicate that the order of aging/freezing/thawing sequence could be an overriding factor affecting quality attributes of frozen/thawed meat over freezing rate. Further studies involving various thawing and freezing rate combined with different aging/freezing/thawing sequence would be warranted.

MCD diet-induced steatohepatitis is associated with alterations in asymmetric dimethylarginine (ADMA) and its transporters.

Using an experimental model of NASH induced by a methionine-choline-deficient (MCD) diet, we investigated whether changes occur in serum and tissue levels of asymmetric dimethylarginine (ADMA). Male Wistar rats underwent NASH induced by 8-week feeding with an MCD diet. Serum and hepatic biopsies at 2, 4 and 8weeks were taken, and serum enzymes, ADMA and nitrate/nitrite (NOx), were evaluated. Hepatic biopsies were used for mRNA and protein expression analysis of dimethylarginine dimethylaminohydrolase-1 (DDAH-1) and protein methyltransferases (PRMT-1), enzymes involved in ADMA metabolism and synthesis, respectively, and ADMA transporters (CAT-1, CAT-2A and CAT-2B). Lipid peroxides (TBARS), glutathione, ATP/ADP and DDAH activity were quantified. An increase in serum AST and ALT was detected in MCD animals. A time-dependent decrease in serum and tissue ADMA and increase in mRNA expression of DDAH-1 and PRMT-1 as well as higher rates of mRNA expression of CAT-1 and lower rates of CAT-2A and CAT-2B were found after 8-week MCD diet. An increase in serum NOx and no changes in protein expression in DDAH-1 and CAT-1 and higher content in CAT-2 and PRMT-1 were found at 8weeks. Hepatic DDAH activity decreased with a concomitant increase in oxidative stress, as demonstrated by high TBARS levels and low glutathione content. In conclusion, a decrease in serum and tissue ADMA levels in the MCD rats was found associated with a reduction in DDAH activity due to the marked oxidative stress observed. Changes in ADMA levels and its transporters are innovative factors in the onset and progression of hepatic alterations correlated with MCD diet-induced NASH.

Utilization of fluorescence spectroscopy as a novel approach to evaluate the oxidative stability in beef retail displayed

Beef samples from grazing steers finished with different seed-supplemented diets were vacuum packaged for 3, 14 and 56days (VC) and subsequently exposed to aerobic conditions (AE) for 0 and 5days. Different fluorescent compounds of interest in the oxidation process were detected in meat, namely tryptophan residues, Schiff bases and porphyrins. Tryptophan intensity fluorescence increased with 14days of VC; while Schiff bases intensity increased (P<0.05) in beef samples stored under VC-56 and in all samples after AE-5days. Porphyrins increased (P<0.05) gradually with the extension of vacuum storage time, but were degraded in beef with long vacuum storage and 5days of AE. Higher levels of porphyrins in beef under VC were correlated (P<0.05) with lower redness and higher TBARS after AE-5. This study revealed the potential of fluorescence signals to detect oxidative changes in beef under different storage conditions using a fast and nondestructive method such as fluorescence spectroscopy.

Meat physicochemical properties, fatty acid profile, lipid oxidation and sensory characteristics from three North African lamb breeds, as influenced by concentrate or pasture finishing diets

This study investigated the meat quality of lambs from three North African breeds (Barbarine, BB; Queue Fine de l’Ouest, QFO; and Noire de Thibar, NT) reared on concentrate (S) or on pasture (P). A total of 18 P and 18 S lambs (20kg initial body weight) were used, with 6 P and 6 S lambs for each breed. After 67 days, all lambs were slaughtered at 26kg final body weight and meat quality was studied. The pH of S lambs 1h post-mortem was lower than that of P lambs (p=0.001). Water cooking loss, colour and sensory quality were not affected by both factors. The pasture and the concentrate meats had the same proportions of lipids and proteins; however QFO and BB breeds had more intramuscular fat than NT breed. The saturated fatty acid proportion was higher for S than P groups (50.63 vs. 44.48%, respectively) and for QFO compared to other breeds. C18:1 was higher for S groups, while C18:2, C18:3 and CLA were higher for P groups. The S group had higher lipid oxidation, while the QFO breed had the highest TBARS. P lambs may have healthier meat than S lambs and the NT breed had the leanest meat with higher concentration of desirable FAs.

Innovative targets involved in the progression of NASH: Asymmetric-dymethylarginine (ADMA) and its cationic transporters

Background: The methionine choline-deficient (MCD) diet results in liver injury similar to humannonalcoholic steatohepatitis (NASH). Recent data demonstrated that after methionine administration an increase in plasma asymmetric-dimethylarginine (ADMA), an inhibitor of nitric oxide synthase, and a decrease in hepatic dimethylarginine-dimethylaminohydrolase (DDAH-1), enzyme involved in ADMA metabolism, occur. Aim: Using an experimental model of NASH induced by MCD diet, this study investigated whether changes in serum levels of ADMA and tissue content of DDAH-1 occur [Kusku-Kiraz Z., Genc S., Bekpinar S., et al. Circulating levels of apelin, glucagon-like peptide and visfatin in hypercholesterolemic–hyperhomocysteinemic guinea-pigs: their relation with NO metabolism. Molecular and Cellular Biochemistry 2015;400:69–75;Magne J., Huneau J.-F., Borderie D., Mathe V., Bos C., Mariotti F. Plasma asymmetric and symmetric dimethylarginine in a rat model of endothelial dysfunction induced by acute hyperhomocysteinemia. Amino Acids 2015, http://dx.doi.org/10.1007/s00726-015-1959-4]. Materials and methods: Male Wistar rats underwent to NASH induced by 8 weeks of feeding with MCD diet. Serum and hepatic biopsies at 2, 4 and 8 weeks were used: serum enzymes (AST, ALT) and ADMA were evaluated. Hepatic biopsies were used for the analysis of mRNA expression of DDAH-1 and ADMA transporters (CAT-1, CAT-2A and CAT-2B). Tissue total lipids, lipid peroxides (TBARS), glutathione and DDAH activity were also quantified. Results: As expected, an increase in serum AST and ALT and in hepatic total lipids were detected in MCD animals. A time-dependent decrease in serum ADMA and increase in mRNA expression of DDAH-1 were found in MCD group. Higher mRNA expression of CAT-1, lower mRNA expression of CAT-2A and no changes in CAT-2B were found after 8 weeks using MCD diet. The hepatic DDAH activity decreased with a concomitant increase in oxidative stress, as demonstrated by high TBARS levels and low glutathione content. Conclusions: A decrease in serum ADMA levels and an increase in DDAH-1mRNA found inMCD rats were associated with a reduction in DDAH activity due to the marked oxidative stress observed. Changes in ADMA levels and its transporters represent innovative factors involved in the onset and the progression of hepatic alteration correlated with MCD-diet-induced NASH. Funding: Supported by Fondazione Cariplo, grant n◦ 2011-0439.

Demographic Responses to Oxidative Stress and Inflammation in the Wandering Albatross (Diomedea exulans).

One of the major challenges in ecological research is the elucidation of physiological mechanisms that underlie the demographic traits of wild animals. We have assessed whether a marker of plasma oxidative stress (TBARS) and plasma haptoglobin (protein of the acute inflammatory phase response) measured at time t predict five demographic parameters (survival rate, return rate to the breeding colony, breeding probability, hatching and fledging success) in sexually mature wandering albatrosses over the next four years (Diomedea exulans) using a five-year individual-based dataset. Non-breeder males, but not females, having higher TBARS at time t had reduced future breeding probabilities; haptoglobin was not related to breeding probability. Neither TBARS nor haptoglobin predicted future hatching or fledging success. Haptoglobin had a marginally positive effect on female survival rate, while TBARS had a marginally negative effect on return rate. Our findings do not support the role for oxidative stress as a constraint of future reproductive success in the albatross. However, our data point to a potential mechanism underlying some aspects of reproductive senescence and survival. Our results also highlight that the study of the consequences of oxidative stress should consider the life-cycle stage of an individual and its reproductive history.

Aging-related changes in oxidative stress response of human endothelial cells.

Oxidative stress is strongly associated with aging and age-related diseases and plays a crucial role in endothelial dysfunction development. To better understand the molecular mechanisms of aging and stress response in humans, we examined changes to young and older human endothelial cells over time (72, 96 and 120h), before and after H2O2-induced stress. We measured the expression of the deacetylase Sirtuin 1 (Sirt1) and its transcriptional target Forkhead box O3a (Foxo3a); TBARS, a well-known marker of overall oxidative stress, and catalase activity as index of antioxidation. Moreover, we quantified levels of cellular senescence by senescence-associated β galactosidase (SA-βgal) assay. Under oxidative stress induction older cells showed a progressive decrease of Sirt1 and Foxo3a expression, persistently high TBARS levels with high, but ineffective Cat activity to counteract such levels. In addition cellular senescence drastically increased in older cells compared with Young cells both in presence and in the absence of oxidative stress. By following the cell behavior during the time course, we can hypothesize that while in young cells an oxidative stress induction stimulated an adequate response through activation of molecular factor crucial to counteract oxidative stress, the older cells are not able to adequately adapt themselves to external stress stimuli. During their life, endothelial cells impair the ability to defend themselves from oxidative stress stimuli. This dysfunction involves the pathway of Sirt1 a critical regulator of oxidative stress response and cellular lifespan, underlining its crucial role in endothelial homeostasis control during aging and age-associated diseases.

Roles of selenoprotein antioxidant protection in zebrafish, Danio rerio, subjected to dietary oxidative stress.

In vertebrates, selenium (Se) is an essential micronutrient for vertebrates that is involved in antioxidant protection and thyroid hormone regulation among other roles and functions through its incorporation into proteins, the selenoproteins. Long-chain polyunsaturated fatty acids, such as docosahexaenoic acid (DHA), are essential nutrients for fish although high dietary levels may lead to increased oxidative stress due to the high degree of unsaturation. The present study investigated the effects of Se supplementation on zebrafish, Danio rerio, oxidative status together with selenoprotein expression profiles when subjected to a high-DHA diet. Fish were fed for 8weeks with one of the four experimental diets, containing high or low DHA in combination with or without organic Se (7mg/kg). Fish performance, Se content, fatty acid composition and TBARS of zebrafish were determined, as well as gene expression of selected selenoproteins in liver and muscle. The Se levels in whole fish reflected dietary content. High dietary DHA increased oxidative stress as indicated by reduced growth and high TBARS content, although Se supplementation reduced oxidation. The expression patterns of selenoproteins varied between liver and muscle with only deiodinase type II displaying a transcriptional response when high dietary Se was supplied. High dietary DHA decreased selenoprotein W expression in muscle and sps2 expression in liver regardless of the dietary Se content. These data suggest that oxidative stress protection associated with a high dietary intake of Se may not be solely mediated by transcriptional changes in teleost selenoprotein expression.

Bacterial Counts and Oxidative Properties of Chicken Breast Inoculated with Salmonella Typhimurium Exposed to Gaseous Ozone

AbstractPoultry meats are highly perishable due to bacterial contamination; thus, elimination of bacterial contaminants is a challenge for food safety industry. This study was designed to evaluate the bacterial counts and oxidative properties of chicken breast contaminated with Salmonella Typhimurium (ST) exposed to gaseous ozone during refrigerated storage. Slices of chicken breast were inoculated with ST by immersing them in peptone water containing 1.0 × 107 cfu of ST per milliliter peptone water. Samples were placed in a container with normal air (no ozone) or in a container equipped with an ozone generator that produce a continuous flux of ozone (10 × 10−6 kg O3/m3/h) and negative ions. Gaseous ozone exposure significantly reduced ST and the total aerobic and anaerobic bacterial counts during storage compared with the nontreatment group (P &lt; 0.05). Gaseous ozone exposure significantly reduced CIE L* and increased CIE b* surface color values after 3 and 2 days of storage, respectively (P &lt; 0.05). Gaseous ozone exposure significantly inhibited catalase and glutathione peroxidase activity after 3 days (P &lt; 0.05). A higher TBARS (2‐thiobarbituric acid reactive substances) value (P &lt; 0.05) was found in chicken breast subjected to ozone exposure after 3 days of storage. In conclusion, gaseous ozone exposure reduced the bacterial counts in chicken breast from the beginning of the study and affected the oxidative properties on the last day of the study.Practical ApplicationsThis study shows that gaseous ozone exposure can be used as an antimicrobial agent for refrigerated meat. This information will be useful in the development of an effective ozone generator inside a refrigerator. Further studies regarding the appropriate ozone concentrations are needed.

Vitamin D deficiency aggravates nephrotoxicity, hypertension and dyslipidemia caused by tenofovir: role of oxidative stress and renin-angiotensin system.

Vitamin D deficiency (VDD) is prevalent among HIV-infected individuals. Vitamin D has been associated with renal and cardiovascular diseases because of its effects on oxidative stress, lipid metabolism and renin-angiotensin-aldosterone system (RAAS). Tenofovir disoproxil fumarate (TDF), a widely used component of antiretroviral regimens for HIV treatment, can induce renal injury. The aim of this study was to investigate the effects of VDD on TDF-induced nephrotoxicity. Wistar rats were divided into four groups: control, receiving a standard diet for 60 days; VDD, receiving a vitamin D-free diet for 60 days; TDF, receiving a standard diet for 60 days with the addition of TDF (50 mg/kg food) for the last 30 days; and VDD+TDF receiving a vitamin D-free diet for 60 days with the addition of TDF for the last 30 days. TDF led to impaired renal function, hyperphosphaturia, hypophosphatemia, hypertension and increased renal vascular resistance due to downregulation of the sodium-phosphorus cotransporter and upregulation of angiotensin II and AT1 receptor. TDF also increased oxidative stress, as evidenced by higher TBARS and lower GSH levels, and induced dyslipidemia. Association of TDF and VDD aggravated renovascular effects and TDF-induced nephrotoxicity due to changes in the redox state and involvement of RAAS.

Effects of passion fruit (Passiflora edulis) byproduct intake in antioxidant status of Wistar rats tissues

Passion fruit (Passiflora edulis) is a native species from Brazil explored in fruit culture. Peels are byproducts of juice industrial processing and are usually discarded. They are source of fibers and other bioactive substances, which may have antioxidant role and to protect cells against oxidative stress. This study aimed to evaluate the antioxidant status of P. edulis peel flour in vivo. The male Wistar rats (77 days old) were divided in Peel and Control groups (n = 4). Control group was fed with standard diet (AIN-93M) and Peel group, received a diet in which fifty percent of the cellulose content was replaced by fiber from PPF. After 15 days, the animals were anaesthetized and sacrificed. Peel group consumed greater amount of diet without alterations in body weight of animals. The experimental group showed no differences in serum antioxidant status (FRAP and TBARS assays) (P > 0.05), but they presented lower antioxidant potential according to ORAC assay (P < 0.05). In the kidneys of Peel group, a reduction in lipid peroxidation by TBARS assay (P < 0.05) was observed. In addition, the liver of the animals fed with PPF showed high TBARS levels, increased glutathione reductase activity (GR), decreased glutathione peroxidased activity (GPx) and superoxide dismutase activity (SOD).

Effect of krill phospholipids versus soybean lecithin in microdiets for gilthead seabream (Sparus aurata) larvae on molecular markers of antioxidative metabolism and bone development

The objective of the present study was to compare the effectiveness of dietary marine phospholipids (MPL) obtained from krill and soybean lecithin (SBL) on the rearing performance and development of seabream (Sparus aurata) larvae. Larvae were fed from 16 to 44 day posthatching (dph) five formulated microdiets with three different levels (50, 70 and 90 g kg–1) of phospholipids (PL) obtained either from an MPL or from a SBL source. Larvae-fed MPL show a higher survival, stress resistance and growth than those-fed SBL, regardless the dietary PL level. Overall, the increase in MPL up to 70 g kg–1 total PL in diet was enough to improve larval gilthead seabream performance, whereas even the highest SBL inclusion level (90 g kg–1 PL) was not able to provide a similar success in larval growth or survival. Inclusion of SBL markedly increased the peroxidation risk as denoted by the higher TBARs in larvae, as well as a higher expression of CAT, GPX and SOD genes. Moreover, SBL tends to produce larvae with a lower number of mineralized vertebrae and a lower expression of osteocalcin, osteopontin and BMP4 genes. Finally, increasing dietary MPL or SBL lead to a better assimilation of polyunsaturated fatty acids in the larvae, n-3HUFA (especially 20:5n-3) or n-6 fatty acids (especially 18:2n-6), respectively. In conclusion, MPL had a higher effectiveness in promoting survival, growth and skeletal mineralization of gilthead seabream larvae in comparison with SBL.

Anti-Oxidative, Anti-Hyperglycemic and Lipid-Lowering Effects of Aqueous Extracts of &amp;lt;i&amp;gt;Ocimum sanctum&amp;lt;/i&amp;gt; L. Leaves in Diabetic Rats

The present study was conducted to investigate the effect of aqueous extracts of Ocimum sanctum L. leaves on blood glucose, serum lipid profile and anti-oxidative activity to protect various risk organs in DM rats. Ocimum sanctum L. leaves were extracted using water, then the total phenolic content was determined. Three groups of male Wistar rats were used including normal control rats, DM rats and DM rats daily fed with aqueous extracts of Ocimum sanctum L. leaves (AQOS) for three weeks. DM rats were induced by intraperitoneal injection of streptozotocin (65 mg/kgbw). The results show that three weeks of diabetic induction increased blood glucose, serum lipid profile and serum levels of AST, ALT, ALP, LDH, CK-MB, creatinine and BUN. AQOS significantly decreased blood glucose, serum lipid profile and serum levels of AST, ALT, ALP, LDH, CK-MB, creatinine and BUN. The low level of serum insulin was also raised by AQOS. AQOS suppressed high TBARS level and raised the activities of antioxidant enzymes in the liver, kidney and cardiac tis- sues. Histopathological results show that AQOS preserved the liver, kidney and myocardial tissues. It can be concluded that AQOS had anti-hyperglycemic, anti-hyperlipidemic, and free radical sca- venging effects providing organ protection from diabetes. The phenolic compounds contained in AQOS might be responsible for these activities.

MEAT QUALITY OF LOCAL AND HYBRID RABBITS

pH, colour and oxidative status were evaluated to study the effect of rabbit genotype on meat quality. Commercial Hybrids, selected for high growth rate and a local population, characterized by slow growing, were used. Meat quality characteristics of L. lumborum and B. femoris muscles showed significant differences between genotypes. Local population had higher pHu values but lower pH fall values than Hybrids. Hybrids showed higher lightness values and TBARS contents than local population. Meat quality parameters were influenced by genotype. The differences between genotypes could be related to the different degree of maturity because the rabbits, in relation to the different growth rate, were slaughtered at the same weight but at different age.

Lipid and colour stability of M. longissimus muscle from lambs fed camelina or linseed as oil or seeds

Colour and lipid stability of M. longissimus dorsi (LD) from sheep fed diets containing different lipid sources (Megalac (MG), camelina oil (CO), linseed oil (LO), NaOH-treated camelina seed (CS), NaOH-treated linseed (LS) or CO treated with ethanolamine (CA)) were examined. After 100days on-feed, samples of LD were collected, fatty acid profile determined and colour and lipid oxidation (2-thiobarbituric acid reactive substances; TBARS) measured during retail display in high oxygen packaging. The LS ration was most effective in increasing the 18:3n−3 and conjugated linoleic acid (CLA) concentration in muscle. Within camelina, CA resulted in the highest 18:3n−3 and lowest CLA concentration in muscle. There was no difference in colour stability. Oil (seed) supplementation increased TBARS compared to MG in the early part of display while linseed-based rations tended to cause higher TBARS than camelina-based rations. Higher muscle 18:3n−3 concentration was associated with higher oxidation during early retail display but this was not reflected in a loss of colour stability.

Effects of dietary inclusion of dehydrated lucerne and whole linseed on rabbit meat quality

The effect of dietary use of dehydrated lucerne meal (DLM) and whole linseed (LIN) on chemicalphysical traits, fatty acid composition, susceptibility to lipid oxidation, and sensory quality of rabbit meat and meat products (hamburgers) was studied. Two groups of 128 weaned rabbits (37 d-old) were fed on diets containing 25 or 35% DLM. At 64 d of age, the rabbits were randomly divided into four groups; two of them received the same diet whereas the others were fed on diets containing both 25 or 35% DLM and 8% linseed until slaughtering (87 d). The main effects of DLM (25 vs. 35%) and LIN (0 vs. 8%) were considered according to a 2×2 factorial statistical design. With regard to the effect of lucerne, the main result was the higher content of a-linolenic acid in meat from rabbits fed the higher level of DLM (6.34 vs. 5.82% in DLM35 and DLM25, respectively; P<0.05) without impairing the lipid susceptibility to oxidation. The use of linseed strongly (P<0.01) influenced the fatty acid composition of the meat by enhancing the content of polyunsaturated fatty acids (PUFA, 33.68 vs. 27.79%; for LIN8 and LIN0, respectively) and mainly a-linolenic acid which was three times higher in LIN8 rabbits (9.42 vs. 2.95%; P<0.01), producing a lower n-6/n-3 PUFA ratio (2.28 vs. 6.59; P<0.01). However, the higher level of PUFA was related to a higher susceptibility to lipid oxidation (TBARS) of both meat and frozen (-20°C for 3 or 6 months) meat batters for hamburgers production. Despite the higher TBARS, sensory differences among hamburgers were detected only at six months frozen storage. Finally, the use of linseed did not determine a higher colour variation of the packaged hamburgers during storage (14 d at 2-4°C). This experiment indicates a very quick and significant rise in the a-linolenic acid content (three times higher after 3 weeks) when rabbits were fed during the finishing period with a diet containing 8% linseed. However, despite the nutritional importance of this essential fatty acid, care must be taken to avoid lipid oxidation and detrimental effects on the sensory qualities of meat and meat products during processing and subsequent storage.