•PPE cause an increase in performance parameters of broilers reared under heat stress.•PPE improve the morphology of jejunal in heat stressed broilers.•PPE improve the broiler meat quality during ...refrigeration storage.
This study was conducted to evaluate the effects of dietary pomegranate peel extract (PPE) on growth performance, carcass characteristics, serum metabolites, immune response, jejunal morphology, and meat quality of broiler chickens reared under heat stress (HS). Two hundred 1-d-old male broiler chickens were randomly assigned to 4 treatments with 5 replicates of 10 broiler chickens each. The dietary treatments consisted of basal diets supplemented with PPE at levels of 0 (control), 250, 450, and 650 mg PPE/kg. The broiler chickens were subjected to HS (37 ± 1 °C for 7 h/d and 21 ± 1 °C for 17 h/d) from d 25 to 42. Dietary PPE supplementation linearly increased the body weight gain during the starter (P = 0.004) and overall experimental (P = 0.033) periods. Dietary supplementation of PPE quadratically decreased the feed intake during the starter period (P = 0.033). Furthermore, PPE supplementation linearly improved the feed conversion ratio during the finisher (P = 0.035) and overall experimental (P = 0.046) periods. Dietary PPE addition did not affect the relative weights of carcass, breast, thigh, abdominal fat, liver, pancreas, gallbladder, heart, gizzard, bursa of Fabricius, and spleen. Dietary supplementation with PPE linearly reduced the plasma triglycerides (P = 0.049) and alanine aminotransferase (P = 0.005) concentrations, but linearly increased the plasma concentration of high-density lipoprotein at d 24 (P = 0.044). Dietary PPE addition linearly reduced the plasma concentrations of cholesterol (P = 0.035), low-density lipoprotein (P = 0.032), alkaline phosphatase (P = 0.001), and alanine aminotransferase (P = 0.025) at d 42. The primary total anti- sheep RBC titer linearly increased with dietary PPE addition (P = 0.006). It also linearly enhanced the secondary total (P = 0.024) and Ig G (P = 0.045) anti-SRBC titers. The dietary treatments did not affect the jejunal villus height, villus width, and villus height / crypt depth ratio. Dietary PPE supplementation linearly reduced the malondialdehyde concentration in breast muscle during refrigerated storage (P < 0.05); however, linearly increased water holding capacity of breast meat during refrigerated storage (P < 0.05). It is concluded that dietary supplementation with PPE, at levels up to 650 mg/kg, improved the growth performance and plasma lipid profile of broiler chickens reared under HS. Furthermore, dietary PPE addition also preserved the quality of meat during refrigerated storage.
•Limited research was conducted to investigate effects of quercetin (flavonoid) on growth performance, meat stability, and immunological response in broiler chickens.•Broiler chickens fed diet with ...increasing inclusion of quercetin supplementation improved body weight gain quadratically.•Increasing dose range from 250 to 1000 mg/kg of quercetin supplementation can linearly increase the concentration of total antioxidant capacity, total superoxide dismutase, and reduce the concentration of malondialdehyde linearly.•The concentration of tumor necrosis factor-α was linearly elevated by adding an increasing dosage of quercetin in the diet.
This study was conducted to determine the effect of quercetin supplementation on growth performance, meat stability, excreta gas emission, and immunological response in broiler chickens. A total of 640 broiler chickens were randomly assigned to 1 of the 4 treatments (10 replicates per treatment with 18 chickens per pen). Dietary treatments: basal diet contained 0, 250, 500, and 1,000 mg quercetin/kg. The chronic heat stress condition was maintained (32 °C) for 24 h from the fourth day of the study. Growth performance was assessed on d 0, 7, 21, and 35, whereas all other response criteria were determined on d 35. Overall, a quadratic effect of quercetin supplementation on body weight gain (BWG) was observed when quercetin supplementation was increased (P < 0.05). And these responses were maximized in the broiler chickens fed diet with 250 mg quercetin/kg. There was a linear and quadratic effect of quercetin supplementation on Lactobacillus counts (P < 0.05). As the dietary supplementation of quercetin increased, the content of total superoxide dismutase (T-SOD) and total antioxidant capacity (T-AOC) linearly increased (P < 0.05), while the malondialdehyde (MDA) concentration linearly reduced in breast muscle (P < 0.05). There was a linear decrease in abdominal fat content when quercetin supplementation was increased (P < 0.05). The concentration of tumor necrosis factor-α (TNF-α) linearly increased by adding an increasing dosage of quercetin in the diet (P < 0.05). In conclusion, the addition of quercetin in the diet could improve BWG which reflected a beneficial effect of quercetin for growth performance. Increasing dose range from 0 to 1,000 mg quercetin/kg could linearly increase the content of T-AOC and T-SOD, and reduce the concentration of MDA, which reflected that the increased quercetin supplementation can enhance meat stability. Furthermore, supplementation of quercetin could increase the level of TNF-α, which indicated the ability of quercetin to enhance the immune capacity of broiler chickens.
Summary
Raspberry pomace extracts isolated with supercritical carbon dioxide (SCE) and pressurised ethanol/water (ETE) were tested in beef burgers. Only ETE additives effectively inhibited lipid ...oxidation and the growth of microorganisms, as it was observed by measuring the changes of thiobarbituric acid reactive substances, bacterial counts and the content of O2 and CO2 during storage in the modified atmosphere package. ETE additives also demonstrated some meat colour preservation effects, which were assessed by the intensity of hamburger colour and metmyoglobin concentration. However, ETE additives did not alter burger's taste at the applied concentrations (up to 1%). It may be concluded that the most effective extracts possessing strong antioxidant and antimicrobial activity may be isolated from raspberry pomace by the pressurised liquid extraction with a hydroethanolic solvent; such extracts may be considered as promising additives in meat products for improving their stability and enriching with beneficial to health phytochemicals.
Antioxidant effects of raspberry pomace ethanolic extract in beef burgers.
Sage distillation by-product (SDB) was tested as dietary supplement in lambs for its effects on the lipid profile and meat stability. Segureño lambs from two different rearing systems (ewes grazing ...Mediterranean shrubland vs. ewes fed indoors on barley/lucerne) were weaned at 13kg live weight and given a basal diet (concentrate) or the SDB diet (concentrate with 100gSDBkg−1 feed) until they reached 25kg. Intramuscular fat composition and meat stability were determined. SDB increased n-3 PUFA and polyphenol intake. It was necessary to provide an n-3 PUFA-promoting diet to both ewes (by grazing) and lambs (SDB) to increase the proportions of total PUFAs, n-3 PUFAs and CLA in meat. SDB had no antioxidant or antimicrobial effects; on the contrary, lipid oxidation, rancidity and lean discoloration were higher in retailed meat with high PUFA levels. Thus, the SDB-based diet used needs to be readjusted to ensure that meat quality is improved irrespective of the diet provided to ewes.
•Using DS adds linolenic acid and sage polyphenols to the lamb diet.•Combining ewe grazing and DS-diet increases n-3 PUFA and CLA levels in meat•DS did not protect against oxidation in the meat with increased PUFAs.•DS-diet should be readjusted to improve meat quality regardless of the ewe diet.
Fresh meat products are highly perishable and require optimal packaging conditions to maintain and potentially extend shelf-life. Recently, researchers have developed functional, active packaging ...systems that are capable of interacting with food products, package headspace, and/or the environment to enhance product shelf-life. Among these systems, antimicrobial/antioxidant active packaging has gained considerable interest for delaying/preventing microbial growth and deteriorative oxidation reactions. This study evaluated the effectiveness of active linear low-density polyethylene (LLDPE) films coated with a polycaprolactone/chitosan nonwoven (Film 1) or LLDPE films coated with a polycaprolactone/chitosan nonwoven fortified with Colombian propolis extract (Film 2). The active LLDPE films were evaluated for the preservation of fresh pork loin (longissimus dorsi) chops during refrigerated storage at 4 °C for up to 20 d. The meat samples were analyzed for pH, instrumental color, purge loss, thiobarbituric acid reactive substances (TBARS), and microbial stability (aerobic mesophilic and psychrophilic bacteria). The incorporation of the propolis-containing nonwoven layer provided antioxidant and antimicrobial properties to LLDPE film, as evidenced by improved color stability, no differences in lipid oxidation, and a delay of 4 d for the onset of bacteria growth of pork chops during the refrigerated storage period.
The aim of this work was to evaluate the effect of an olive extract (OE) on the physicochemical and microbiological characteristics, lipid oxidation and volatile compounds of beef patties stored both ...aerobically and under modified atmosphere packaging for 15 days at 4 °C. The antioxidant and antimicrobial effects of the OE were compared to those of sulfite. Four formulations were elaborated according to the antioxidant and dose used: without antioxidant, C; 300 mg potassium metabisulfite/kg product, S; 150 mg OE/kg product, OE1; and 250 mg of OE/kg product, OE2. The parameters analyzed were pH, water activity, color, lipid oxidation (TBARS and volatile organic compounds: hexanal, 2-pentyl-furan, 1-pentanol, 2,3-octanedione and nonanal, 1-octen-2-ol) and total viable counts. The OE delayed the loss of the bright red color of the patties and reduced the lipid oxidation in both types of packaging compared to the control patty. Sulfite was the most effective antioxidant for inhibition of the total viable counts. An OE could be used as a natural antioxidant to delay the lipid oxidation of meat without negatively affecting its physicochemical properties.
Aqueous extract of mate, made from dried leaves of Ilex paraguariensis, St. Hilaire, was shown to be effective during chilled storage for up to 10 days in protecting lipids and vitamin E against ...oxidation in pre-cooked meat balls made from chicken breast added 0.5% salt and packed in atmospheric air. Extracts made with water, methanol, ethanol or 70% aqueous acetone were evaluated by comparing (1) total phenolic content, (2) radical scavenging capacity, (3) effect on lipid oxidation in a food emulsion model, and in liposomes. Based on the three-step evaluation, aqueous mate extract was preferred for food use. Dried leaves were further compared to dried rosemary leaves in chicken meat balls, and mate (0.05 and 0.10%) found to yield equal or better protection than rosemary at the same concentration against formation of secondary lipid oxidation products.
Experiment 1 was conducted to investigate the influences of source and level of dietary magnesium (Mg) supplementation on performance of broilers, thigh meat pH and oxidative deterioration during ...storage. Five hundred and sixty 1-day-old broiler chicks were allotted to seven treatments, each one had four replicates (cages) of 20 chicks. The basal dietary Mg contents of the maize–soya bean meal diets were 1.9 and 2.1
g/kg for starter and grower, respectively, and the three organic Mg (proteinate) or inorganic Mg (oxide) supplementation levels were 0.5, 1.0 and 2.0
g/kg, respectively. Mg supplementation level did not influence feed intake and growth performance of chicks. Thigh meat pH was not influenced by the oxide Mg, but was elevated quadratically (
R
2=0.999,
P<0.01) by increased dietary inclusion level of the proteinate Mg. Thiobarbituric acid reactive substance (TBARS) in the thigh muscle stored over 4 days at 4
°C tended to decrease by both the oxide and the proteinate Mg supplementation, and a negative correlation between the meat TBARS value and the proteinate Mg supplementation level existed (
R
2=0.987,
P=0.058). In Experiment 2, 432 broiler chicks were randomly allocated into six treatments with three replicates (cages) each of 24 birds. The dietary Vitamin E supplementation level was 100
mg/kg, and Mg inclusion level was 2.0
g/kg as the oxide or as the proteinate, respectively. The results showed that addition of Vitamin E at 100
mg/kg significantly improved (
P<0.05) the growth and feed conversion ratio of broilers fed the control diet during 0–3 weeks of age. Vitamin E significantly (
P<0.05) decreased TBARS values of the hepatic tissue and the thigh meat during storage, but did not influence activities of hepatic catalase (CAT) and superoxide dismutase (SOD). Mg supplementation in both forms did not significantly influence the growth of birds, but proteinate Mg supplementation at 2.0
g/kg did improve the feed conversion of control birds during 0–3 weeks, and the difference between Mg sources was significant (
P<0.05). Mg supplementation significantly (
P<0.01) reduced the TBARS values in the liver and the thigh muscle, and the proteinate Mg was more efficient than the oxide (
P<0.01), but there was no interaction between Mg and Vitamin E. Mg supplementation significantly elevated the activity of catalase (
P<0.01) and tended to increase the activity of superoxide dismutase (0.05<
P<0.10), but there were no significant differences between two sources of Mg. The results suggest that Mg has the capability of reducing oxidation, and could be used to improve and stabilize chicken meat quality; the proteinate Mg is more efficient than the oxide.
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