Transcriptome Analysis of Protocatechualdehyde against Listeria monocytogenes and Its Effect on Chicken Quality Characteristics.

The development of natural antimicrobial agents offers new strategies for food preservation due to the health hazards associated with the spoilage of meat products caused by microbial contamination. In this paper, the inhibitory mechanism of protocatechualdehyde (PCA) on Listeria monocytogenes was described, and its effect on the preservation of cooked chicken breast was evaluated. The results showed that the minimal inhibitory concentration (MIC) of PCA on L. monocytogenes was 0.625 mg/mL. Secondly, PCA destroyed the integrity of the L. monocytogenes cell membrane, which was manifested as a decrease in membrane hyperpolarization, intracellular ATP level, and intracellular pH value. Field emission gun scanning electron microscopy (FEG-SEM) observed a cell membrane rupture. Transcriptome analysis showed that PCA may inhibit cell growth by affecting amino acid, nucleotide metabolism, energy metabolism, and the cell membrane of L. monocytogenes. Additionally, it was discovered that PCA enhanced the color and texture of cooked chicken breast meat while decreasing the level of thiobarbituric acid active substance (TBARS). In conclusion, PCA as a natural antibacterial agent has a certain reference value in extending the shelf life of cooked chicken breast.

Effects of adding nano-emulsified plant oil and probiotics to drinking water during different periods besides sex on processing characteristics, physicochemical properties, and meat quality traits of broiler chickens.

Introduction: High-quality meat is one of the consumer demands. Therefore, several studies have concluded that supplementing broilers with natural additives can improve meat quality. This study was carried out to evaluate the effects of nano-emulsified plant oil (Magic oil®) and probiotic (Albovit®) as water additives (at the rate of 1 ml/L and 0.1 g/L, respectively) during different growing periods on processing characteristics, physicochemical properties, and meat quality traits of broilers chickens. Methods: A total number of 432-day-old Ross broiler chicks were randomly assigned to one of six treatment groups according to the growing periods in which magic oil and probiotics were added to drinking water, each with nine replicates and eight birds per replicate (4♂ and 4♀). On day 35, birds' processing characteristics, physicochemical properties, and meat quality traits were examined. Results and discussion: The results showed that treatments had a significant (P < 0.001) impact on cooking loss, cohesiveness, and chewiness. The male broiler chickens had higher (P ≤ 0.05) initial lightness, initial whiteness index, water holding capacity, shear force, live weight, hot and chilled carcass weights, as well as lower gizzard and neck percentages than females. The interactions between treatments and sex showed a significant (P < 0.001) impact on cooking loss, shear force, hardness, springiness, and chewiness. In conclusion, supplementing male broiler chickens with Magic oil and probiotic, particularly from 0-30 days of age had favorable meat chewiness as a result of lower cohesiveness and hardness higher springiness, and the most convenient cooking loss value. Magic oil and probiotic, especially in males, is advisable to be supplemented in water of growing broilers chicken programs from 0 to 30 days of age. Moreover, further studies under commercial conditions are recommended to locate the most favorable combination of Magic oil/probiotic supplements for the best processing characteristics and meat quality attributes outcomes.

Potential application of Fe-methionine as a feed supplement on improving the quality of broilers breast meat.

A total of 250 one-day-old Ross 308 male chicks were used to investigate the effects of Fe-methionine (Fe-met) and iron sulfate (FeSO4 .7H2 O) on performance, mineral concentration, meat quality, and oxidative stability of breast. The feeding experiment was performed with five dietary groups including group I (basal diet [BD] + 80 mg/kg FeSO4 ), group II (BD + 60 mg/kg FeSO4 + 20 mg/kg Fe-met), group III (BD + 40 mg/kg FeSO4 + 40 mg/kg Fe-met), group IV (BD + 20 mg/kg FeSO4 + 60 mg/kg Fe-met), and group V (BD + 80 mg/kg Fe-met). The results showed that Fe and Cu content in the breast muscle increased by dietary supplementation of organic and inorganic iron from II to V groups. Dietary groups of II, IV, and V increased L* value and b* value of breast meat. Additionally, redness of breast meat enhanced linearly and quadratically by dietary supplementation of 80 mg/kg Fe as FeSO4 . In addition, dietary supplementation Fe from II to V groups led to a significant increase in pHu at 24-h postmortem while it was negatively correlated with L* value of breast muscle. This study demonstrates that replacing FeSO4 with Fe-Met could improve breast meat yield of broilers. Although 80 mg of Fe-Met improved the iron content of meat, it showed detrimental effects on the lipid oxidation of breast meat.

Effect of chromium-methionine supplementation on meat quality of broilers reared under heat stress / [Efeito da suplementação de cromo-metionina na qualidade da carne de frangos de corte criados em estresse por calor]

Objetivou-se avaliar o efeito da suplementação de cromo-metionina em dietas para frangos de corte criados em estresse por calor, no período de 22 a 43 dias de idade, nos parâmetros de qualidade da carne. Foram utilizados 336 frangos de corte, machos, da linhagem Cobb 500, com 21 dias de idade, distribuídos em delineamento em blocos inteiramente ao acaso, com quatro blocos (cada câmara climática), seis tratamentos (0; 0,10; 0,20; 0,40; 0,80 e 1,20mgkg-1 de Cr na forma de Cr-metionina), oito repetições e sete aves por unidade experimental. Aos 43 dias de idade, duas aves por unidade experimental foram selecionadas e abatidas para avaliação da qualidade da carne de peito, por meio dos parâmetros de pH15min, pH24h, luminosidade (L*), teor de vermelho (a*), teor de amarelo (b*), croma (C*), ângulo hue (Hº), capacidade de retenção de água, perda de peso por cozimento e força de cisalhamento. Houve efeito quadrático (P=0,0070) na capacidade de retenção de água da carne de peito. A suplementação de CrMet não afetou (P>0,05) os demais parâmetros de qualidade da carne. Assim, recomenda-se a suplementação de 0,59mgkg-1 de CrMet para frangos de corte para melhoria da capacidade de retenção de água do peito.(AU)

Feeding of Dehulled-micronized Faba Bean (Vicia faba var. minor) as Substitute for Soybean Meal in Guinea Fowl Broilers: Effect on Productive Performance and Meat Quality.

The present study aimed to assess the effect of dietary substitution of soybean meal (SBM) with dehulled-micronized faba bean (Vicia faba var. minor) in guinea fowl broilers on their growth traits, carcass quality, and meat fatty acids composition. In this trial, 120 day-old guinea fowl keets were randomly assigned to two treatments which were fed from hatch to 12 weeks of age. Birds were fed two wheat middlings-based diets comprising of a control treatment which contained SBM (78.3 g/kg) and a test diet containing dehulled-micronized faba bean (130 g/kg) as the main protein source. Substituting SBM with faba bean had no adverse effect on growth traits, dressing percentage, or breast and thigh muscles relative weight of the guinea fowls. Conversely, a decrease (p<0.05) of abdominal fat was found in guinea fowls fed the faba bean-diet. Breast muscle of birds fed faba bean had higher L* score (p<0.05) and water-holding capacity (p<0.05) than the SBM control diet. Meat from guinea fowls fed faba bean had less total lipids (p<0.05) and cholesterol (p<0.01), and higher concentrations of phospholipids (p<0.01). Feeding faba bean increased polyunsaturated fatty acid concentrations in breast meat and decreased the saturated fatty acid levels. Moreover, dietary faba bean improved the atherogenic and thrombogenic indexes in guinea fowl breast meat. Results indicated that substitution of SBM with faba bean meal in guinea fowl diet can improve carcass qualitative traits, enhancing also meat lipid profile without negatively affecting growth performance.

Relationship between pectoralis major muscle histology and quality traits of chicken meat.

A trial was conducted to evaluate the influence of myodegeneration of pectoralis major muscle on quality traits and chemical composition of breast meat of heavy-size male broilers. For this purpose, a total of 72 pectoralis major muscles were randomly collected from broilers farmed under homogeneous conditions and graded into three categories (mild, n=22; moderate, n=33; and severe, n=17) based on the presence of abnormal fibers (giant fibers, fibers with hyaline degeneration, and damaged and/or necrotic fibers) evaluated by histological and immunohistochemical analysis. Color, pH, drip loss, Allo-Kramer shear values, and chemical composition (moisture, proteins, total lipids, ashes, and collagen) were determined on nonmarinated breast meat. Purge loss and cook loss, total yield, and Allo-Kramer shear values were measured on vacuum-tumbled samples. Samples showing moderate myodegeneration had the highest mean cross-sectional area of the fibers, while samples with severe myodegeneration had myofibers of different diameter and without the characteristic polygonal shape, multifocal degeneration and necrosis, as well as infiltration of CD3-immunoreactive cells. Cooking losses of nonmarinated meat were lower in the mild group with respect to moderate and severe groups (21.4 vs. 24.7 and 24.7%; P<0.001). Breast muscles with severe damage, in comparison with mild degenerated samples, showed higher moisture (75.4 vs. 74.4%; P<0.05) and lower protein percentages (21.1 vs. 22.6%; P<0.001). The lipid percentage of severely degenerated samples was higher than that from moderate group (2.94 vs. 2.36; P<0.05), while collagen content was not modified by histological lesion levels. Marinated meat from the mild group had higher uptake and total marinade yield after cooking. In conclusion, almost all breast fillets of heavy broiler chickens produced under intensive farming systems had histological lesions, which reflected on the chemical composition of the meat and the impaired water holding/binding capacities of the meat.

Supplemental effect of probiotic Bacillus subtilis B2A on productivity, organ weight, intestinal Salmonella microflora, and breast meat quality of growing broiler chicks.

One-day-old Ross 308 male broiler chicks were used to investigate the additive effect during growth of Bacillus subtilis B2A derived from soil samples on productivity, organ weight, intestinal Salmonella microflora, and breast meat quality. Five hundred seventy-six birds (46 ± 0.5 g) were fed 3 different levels of B. subtilis B2A (1.1 × 10(4), 1.0 × 10(5), and 1.0 × 10(6) cfu), in a basal diet based on corn-soybean meal, for 28 d. In the current study, feed intake and feed conversion during 1 to 28 d showed significant improvement as dietary B. subtilis B2A increased from 1.1 × 10(4) to 1.0 × 10(6) cfu (linear, P < 0.05). All blood parameters, such as white blood cells, red blood cells, and lymphocyte and haptoglobin concentrations, were not influenced by B. subtilis B2A added into the diet; however, the weights of the bursa of Fabricius were significantly increased linearly in B. subtilis B2A-fed groups (P < 0.05). Bacillus subtilis B2A supplementation was associated with reduced intestinal Salmonella burden (linear and quadratic, P < 0.05). Breast meat pH and color were not affected by B. subtilis B2A, but 1 d drip loss was decreased (linear, P < 0.05). Our observations suggest that B. subtilis B2A benefits productivity and reduces Salmonella in broilers.