Search Results (10)

This study evaluated the effect of rearing conditions with outdoor access on carcass traits, technological meat quality, and muscle fibre morphology in broiler chickens. Hubbard JA757 broilers were reared until 81 days of age under either control or experimental conditions. Both groups were housed indoors under identical management until day 35; thereafter, the experimental group had access to an outdoor paddock, while the control group remained indoors. At 81 days of age, birds were slaughtered, carcass composition was recorded, and breast (pectoralis major) and thigh (biceps femoris) muscles were analyzed for pH, colour, cooking loss, and shear force. Muscle fibre characteristics were assessed histochemically. Control birds showed higher slaughter and chilled carcass weights, whereas experimentally reared birds exhibited higher carcass yield, lower breast proportion, higher thigh proportion, and reduced abdominal fat. Experimental rearing was associated with higher L* values, higher shear force, and lower cooking loss in both muscles. In the pectoralis major, fibre density was higher in controls, while fibre diameter was higher in the experimental group. In the biceps femoris, the experimental group showed a higher proportion of oxidative βR fibres and larger fibre cross-sectional areas. These results demonstrate that the rearing system influences carcass composition, technological meat properties, and muscle fibre characteristics, leading to distinct phenotypic and technological differences between the groups. Full article

Globally, poultry products have been associated with outbreaks of foodborne illnesses. The aim of this study was to evaluate the effects of cold storage period, carcass weight, and product form on fresh broiler bacteriology and meat quality parameters. A total of 500 one-day-old broiler birds were raised to market age (28–35 days) before slaughtering. The carcasses were classified into two groups: light weight (approximately 1100 ± 50 g) and heavy weight (approximately 1400 ± 50 g). After 4 h of post-chilling aging, 256 carcasses were randomly selected to represent the two categories. Each category of 128 carcasses was randomly distributed into two groups of 64 carcasses. One group was stored as whole carcasses, while the other group was stored as part-cut deboned breast meat at 4 °C for 1, 3, 5, and 7 days of cold storage (16 samples per storage day). Post-chilling temperature, pH, cooking loss, water holding capacity, and shear force were significantly affected by product form and storage period. Water holding capacity and shear force were also affected by carcass weight (p < 0.001). Meat colors (L*, a*, b*, chroma, and hue values) were significantly affected by the storage period. The L* value was only affected by product form and carcass weight (p < 0.01). Crude protein and ether extract were significantly affected by carcass weight and storage period, while ash was only affected by carcass weight. Aerobic plate count, psychrotrophic count, proteolytic count, lipolytic count, and coliform count were significantly increased with storage time. In conclusion, carcass weight had no impact on overall meat quality, but the meat began to deteriorate and showed an increased spoilage rate after five days of cold storage. Full article

The series of biochemical reactions, metabolic pathways, and regulatory interactions that occur during the storage of meat are the main causes of meat loss and waste. The volatile compounds produced by these reactions, such as hydrogen sulfide, acids, and amines, can directly indicate changes in the freshness of meat during storage and sales. In this study, a one-pot hydrothermal method based on a surface control strategy was used to develop nanoparticles of silver with different reactivities, which were further immobilized in agar powder to develop a colorimetric sensor array. Due to the different chemical interactions with various volatile compounds, the colorimetric sensor array exhibited distinct color changes. The study demonstrates significant differences between 12 different volatile compounds and provides a quantitative and visual method to reveal rich detection indicators. The colorimetric sensor array is an economical and practical multi-analyte identification method. It has many potential applications such as food packaging, anti-counterfeiting, health monitoring, environmental monitoring, and optical filters. Full article

The high environmental temperature is one of the main factors challenging the broiler industry during the hot seasons due to it causing more thermal stress. This study aimed to find the effects of heat stress under hot arid environments on the growth performance, carcass traits, and nutritional composition of breast meat in broiler chickens. A total of 240 broiler chickens were allocated into two groups: (1) a control group (thermoneutral environment (TN); 24 ± 0.17 °C) and (2) a heat stress (HS) group, with 30 replicates in each environment. From d 25 to 35 of age, the broiler chickens in the HS group were exposed to 8 h/day of thermal stress (34 ± 0.71 °C) from 8:00 am to 4:00 pm, while the actual recorded value of ambient temperature was 31 °C on average with a relative air humidity (RH) between 48 and 49% for 10 consecutive days (d 25–35 of age). The live body weight (BW), weight gain, and feed intake significantly deteriorated (p < 0.05), and the feed conversion ratio tended to deteriorate (p = 0.055) in the HS group. The hot and cold carcass yields increased (p < 0.05), while the relative heart and liver weights decreased (p < 0.05) in the broiler chickens exposed to HS. The breast meat yield tended to decrease (p = 0.057), while wing meat yields increased significantly (p = 0.050) in heat-stressed broiler chickens. The shrinkage of the carcass percentage increased during chilling (p < 0.001) in the HS group. The ultimate pH values; cooking loss; and contents of moisture, crude protein, and fat of breast meat showed no response (p > 0.05) between the TN and HS groups. The heat-stressed broiler chickens presented lower levels of arachidonic acid (C20:4 (n-6)) (p = 0.01) and eicosadienoic acid (C20:2 (n-6)) (p = 0.050) in the breast meat, while the variations in n-3 polyunsaturated fatty acid were insignificant (p > 0.05) between the groups. In conclusion, our findings confirmed that the hot arid environments could reduce the production performance of broiler chickens and increase carcass shrinkage during chilling, but did not compromise the n-3 polyunsaturated fatty acid and cooking loss in the breast meat. Full article

Herein, we design and prepare large-area silver nanoparticle (Ag NP) films based on evaporation-induced self-assembly, which offers the visual and real-time detection of chilled broiler meat freshness. The color change is based on the fact that an increase in the biogenic amine (BA) concentration causes a change in the absorption wavelength of Ag NPs caused by aggregation and etch of the Ag NPs, resulting in a yellow to brown color change, thus enabling a naked-eye readout of the BA exposure. The Ag NP films exhibit a rapid, sensitive, and linear response to BAs in a wide detection range of 2 µM to 100 µM. The Ag NP films are successfully applied as a quick-response, online, high-contrasting colorimetric sensor for visual detection of the freshness of chilled broiler meat. Full article

In poultry processing, Salmonella and Campylobacter contaminations are major food safety concerns. Peracetic acid (PAA) is an antimicrobial commonly used in commercial poultry processing to reduce pathogen prevalence so as to meet the USDA-FSIS performance standards. The objective of this study was to determine the prevalence of Salmonella and Campylobacter on broiler meat in various steps of commercial poultry processing in plants that use PAA. Post-pick, pre-chill, post-chill, and drumstick chicken samples were collected from three processing plants and mechanically deboned meat (MDM) was collected from two of the three plants. Each plant was sampled thrice, and 10 samples were collected from each processing step during each visit. Among the 420 samples, 79 were contaminated with Salmonella and 155 were contaminated with Campylobacter. Salmonella and Campylobacter contamination on the post-pick samples averaged 32.2%. Significant reductions in Salmonella and Campylobacter were observed in pre-chill to post-chill samples, where the prevalence was reduced from 34% and 64.4% to nondetectable limits and 1.1%, respectively (p < 0.001). Salmonella and Campylobacter remained undetectable on the drumstick samples in all three processing plants. However, the prevalence of Salmonella and Campylobacter on MDM was similar to the post-pick prevalence, which suggests substantial cross-contamination from post-chill to MDM. Full article

This study aimed to evaluate how different percentages of guar meal in feed rations for broiler chickens affect their rearing performance and carcass composition. The experiment was conducted in a group of one hundred sixty Ross 308 broilers randomly allocated to four equinumerous groups (K, G4, G8 and G12). The birds were reared over 42 days with the application of three feeding periods: starter (days 1–21), grower (days 22–35) and finisher (days 36–42). All the feed rations were prepared using maize meal, soybean meal, oil and mineral and vitamin additives. An experimental factor was the share of guar meal in feed rations: group K—0%, G4—4%, G8—8% and G12—12%. It was demonstrated that a higher percentage (8% or 12%) of guar meal in the feed rations had a negative effect on the chickens’ weight gain and feed intake. The birds receiving feed rations supplemented with guar meal featured higher feed conversion levels than those fed rations in which soybean meal was the only protein-rich component (p ≤ 0.05). Birds fed rations with the highest percentage (12%) of guar meal showed a significant decrease in chilled carcass weight and dressing percentage compared with other chickens. A higher percentage (8% or 12%) of guar meal in feed rations had an adverse effect on the birds’ muscularity. In addition, it was demonstrated that their meat was DFD (dark, firm and dry; pH₁ > 6.4), but from a dietary point of view, it contained the smallest amount of intramuscular fat. To sum up, 4% of guar meal should be recommended in broiler chicken feeding to ensure their satisfactory rearing performance and carcass composition, including the physico-chemical properties of their muscles. Full article

In poultry processing, spoilage microbes are persistent microorganisms, which affect the quality of broiler meat. Peracetic acid (PAA) is the most common antimicrobial used by commercial processing plants, which can reduce the prevalence of these microbes. The goal of this study was to determine the concentrations of aerobic bacteria, coliforms, lactic acid bacteria, and Pseudomonas on broiler meat in processing plants that use peracetic acid in various concentrations as the primary antimicrobial. Samples were collected from three processing plants at five processing steps: post-pick (defeathering), pre-chill, post-chill, mechanically deboned meat (MDM), and drumsticks. Samples were rinsed in buffered peptone water for bacteria isolation. Over six log CFU/sample of aerobic plate counts (APC), lactic acid bacteria, and coliforms were detected on post-pick samples. All spoilage bacteria were reduced to nondetectable levels on post-chill samples (p < 0.001). However, the presence of all bacteria on mechanically deboned meat (MDM) samples indicated varying degrees of cross contamination from post-chill and MDM samples. These results suggest PAA effectively reduces spoilage microbes in chilling applications irrespective of differences in PAA concentrations. However, due to the levels of spoilage microbes detected in MDM, it may be worth investigating the potential interventions for this stage of processing. Full article

Monitoring food quality throughout the food supply chain is critical to ensuring global food safety and minimizing food losses. Here we find that simply by mixing an aqueous solution of sugar-stabilized Ag⁺ and amines in an open vessel leads to the generation of Ag NPs and an intelligent evaluation system based on a colorimetric Ag⁺ probe is developed for real-time visual monitoring of food freshness. The self-assembly reaction between methylamine (MA) generated during meat storage and the colorimetric Ag⁺ probe produces different color changes that indicate changes in the quality of the meat. The colorimetric Ag⁺ probe was integrated into food packaging systems for real-time monitoring of chilled broiler meat freshness. The proposed evaluation system provides a versatile approach for detecting biogenic amines and monitoring chilled broiler meat freshness and it has the advantages of high selectivity, real-time and on-site measurements, sensitivity, economy, and safety and holds great public health significance. Full article

The effects of dietary supplementation with extracts of rosemary (RO) and blackcurrant (BC) on the performance indices and the oxidative stability of broiler meat were investigated during a 35-d experiment. For the experiment, 120 one-day-old male Hubbard Flex broiler chicks were randomly allocated to 5 experimental groups (control group and 4 treatments, each in 6 replications, 24 birds per group, 4 birds per replicate) and fed control starter and grower diets or basal diets containing two concentrations (2.5 and 5 g/kg) of the RO and BC extracts. Basic performance traits (body weight gain, feed intake, feed conversion) were recorded during the trial. At the end of the experiment, pectoral and thigh muscles were collected. Thiobarbituric acid (TBA) assays using the muscles samples were performed after 1 and 5 d of chilling (4 °C) and after 90 d of frozen storage (−18 °C). The inclusion of RO and BC in the birds’ diet had no significant effects on weight gain and feed conversion ratio of chickens, or on carcass characteristics, compared with control group. Enrichment of chicken diet with RO and BC did not affect the oxidative stability of chicken breast muscles, but the tested extracts significantly reduced the malondialdehyde (MDA) formation in frozen thigh muscles. Full article