Skeletal muscle proteome and meat quality of broiler chickens subjected to gas stunning prior slaughter or slaughtered without stunning

The study examined the effects of pre-slaughter gas stunning and slaughter without stunning on meat quality and skeletal muscle proteome of broiler chickens. Fifty Cobb broiler chickens were randomly assigned to either a neck cut without pre-slaughter stunning (Halal slaughter) or pre-slaughter gas stunning followed by a neck cut. Samples of Pectoralis major muscle at 7 min, 4 h and 24 h postmortem were analyzed for pH, shear force, color, drip and cooking losses. Proteome profile of the 7 min samples was examined by two-dimensional polyacrylamide gel electrophoresis. Birds subjected to Halal slaughter had higher (P < 0.05) redness than those gas stunned at 4 and 24 h postmortem. Gas-stunned birds had lower (P < 0.05) muscle pH and shear force and higher (P < 0.05) drip and cooking losses compared with those subjected to Halal slaughter throughout postmortem storage. Gas stunning up-regulated (P < 0.05) the expression of beta-enolase, pyruvate kinase and creatine kinase compared with Halal slaughter. Results indicate that pre-slaughter gas stunning hastened postmortem energy metabolism and had detrimental effects on the water holding capacity and redness of broiler breast muscles

Effect of belimbing buluh (Averrhoa bilimbi) juice extract on oxidative stability and microbiological quality of spent chicken meat

This study evaluated the effects of Averrhoa bilimbi juice extract and storage temperature on lipid oxidation and microbial spoilage of spent chicken meat. Ten, 80 weeks old spent chickens were slaughtered, eviscerated and aged for 24 h at 4°C. Thereafter, the Pectoralis major muscles and right thighs were excised and marinated in either A. bilimbi juice extract, pure distilled water, or no marination (control) for either 4 or 9 h at room temperature or 9 or 24 h at 4°C. Lipid oxidation was monitored on the Pectoralis major muscles while the right thighs were assessed for Enterobacteriacea counts. Lipid oxidation was not significantly affected by the type or duration of marination. Marination showed a temperature dependent effect on Enterobacteriacea counts. At room temperature, samples that were marinated by distilled water showed significantly higher Enterobacteriacea counts than the control while those that were marinated with A. bilimbi juice extract showed no growth at both 4 and 9 h of marination. At chilled temperature, marination had no significant effects on the growth of Enterobacteriacea during the 9 or 24 h storage. These results indicated that A. bilimbi juice extract marinade has some antibacterial activities but works better when combined with refrigerated storage

LC–QTOF-MS identification of porcine-specific peptide in heat treated pork identifies candidate markers for meat species determination

The purpose of this study was to identify porcine-specific peptide markers from thermally processed meat that could differentiate pork from beef, chevon and chicken meat. In the initial stage, markers from tryptic digested protein of chilled, boiled and autoclaved pork were identified using LC–QTOF-MS. An MRM method was then established for verification. A thorough investigation of LC–QTOF-MS data showed that only seven porcine-specific peptides were consistently detected. Among these peptides, two were derived from lactate dehydrogenase, one from creatine kinase, and four from serum albumin protein. However, MRM could only detect four peptides (EVTEFAK, LVVITAGAR, FVIER and TVLGNFAAFVQK) that were consistently present in pork samples. In conclusion, meat species determination through a tandem mass spectrometry platform shows high potential in providing scientifically valid and reliable results even at peptide level. Besides, the specificity and selectivity offered by the proteomics approach also provide a robust platform for Halal authentication

Meat quality and muscle proteome of commercial broiler chickens subjected to pre slaughter electrical stunning and gas killing

Stunning prior to slaughter of animal is desired for i) animal welfare ii) high throughput of processing, and iii) meat quality. However, different stunning procedures may alter the biochemical changes thus the outcome on meat quality differently. This study was conducted to determine the effects of electrical stunning and gas killing prior to slaughter on meat quality and skeletal muscle proteome of commercial broiler chickens. The meat quality parameters examined are pH values, cooking loss, drip loss, tenderness and colour values (L*, a*, b*). Two separate experiments were conducted separately. In Experiment 1, 40 commercial broiler chickens (2.60±0.2 kg) were randomly assigned to electrical stunning (constant voltage of 30 V, 0.2 A, 50 Hz for 5s) and control (without stunning). Immediately after stunning, the broilers were subjected to manual neck cut using a sharp knife. In Experiment 2, 40 broiler chickens (2.60±0.2 kg) were randomly assigned to gas killing (40% carbon dioxide, 30% oxygen and 30 % nitrogen) and control (without prior gas killing), following which, the broilers were slaughtered immediately. Pectoralis major muscles were sampled for muscle proteome and the remaining were assigned for muscle pH, tenderness, cooking loss, drip loss and colour assessments at 0, 4 and 24 h postmortem. Muscle samples of the electrically stunned broilers presented lower (p<0.05) cooking loss and lightness values (L*). The gas killing had resulted in lower pH values (p<0.05), lower shear force values (p<0.05), higher cooking loss (p<0.05), higher drip loss (p<0.05) and lower lightness values (p<0.05). The muscle proteome revealed expression changes (p<0.05) of several proteins in both treatments. In electrical stunning, beta enolase, pyruvate kinase muscle isozyme and glycogen phosphorylase were expressed lower as compared to the control. On the contrary, gas killing treatment has significantly increased the expressions of beta enolase and pyruvate kinase, and reduced the expression of creatine kinase. In conclusion, electrical stunning had reduced the glycogen metabolism with improved meat quality. Meanwhile, the gas killing procedure had significantly elevated the glycolysis rate which resulted with poorer meat quality. It seems that the gas killing is more detrimental on meat quality as compared to electrical stunning

Skeletal muscle proteome of commercial broiler chickens as affected by pre slaughter electrical stunning

The pre slaughter electrical stunning is no longer uncommon in halal poultry production nowadays. A sufficient amount of electrical current is applied through the brain to suppress its activity, which results in insensibility towards pain during the neck cutting until death. Proteomics is a field of study useful in unveiling information about proteins such as their identification, post-translational modification and responses towards external factors. It is likely that any intervention prior to slaughter may alter the post-mortem biochemical changes which can be determined through proteomics approach. To date, there is limited data to provide a better insight on the influence of electrical stunning on skelet al muscle proteome in broiler chickens. Hence, this study was conducted with an attempt to determine changes in skelet al muscle proteome of commercial broiler chickens subjected to pre slaughter electrical stunning. Fifty commercial broiler chickens (mixed–sex Cobb, at 42 days old, 2.60±0.2 kg) were randomly allotted to two treatment groups. Twenty five birds were manually shackled and subjected to water bath electrical stunning (at 30V, 0.2A and 50Hz, for 5 sec) prior to neck exsanguination, while the remaining 25 birds were shackled and slaughtered without any prior stunning. Pectoralis major muscle proteome was determined using 2-dimensional gel electrophoresis followed by MALDI-TOF/TOF mass spectrometry analysis. Muscles obtained from the electrically stunned birds presented two fold decreases in the expressions of beta enolase (p<0.05) and pyruvate kinase (p<0.05). All of these proteins belong to a group of enzyme in the glycolytic pathways responsible for generation of ATP. Thus, the decreased expressions of beta enolase, pyruvate kinase and glycogen phosphorylase suggest a possible reduction in the rate of glycogen metabolism following the electrical stunning

An efficient biosorption-based dispersive liquid-liquid microextraction with extractant removal by magnetic nanoparticles for quantification of bisphenol A in water samples by gas chromatography-mass spectrometry detection

In this work, a simple, fast, sensitive, and environmentally friendly method was developed for preconcentration and quantitative measurement of bisphenol A in water samples using gas chromatography with mass spectrometry. The preconcentration approach, namely biosorption-based dispersive liquid-liquid microextraction with extractant removal by magnetic nanoparticles was performed based on the formation of microdroplet of rhamnolipid biosurfactant throughout the aqueous samples, which accelerates the mass transfer process between the extraction solvent and sample solution. The process is then followed by the application of magnetic nanoparticles for easy retrieval of the analyte-containing extraction solvent. Several important variables were optimized comprehensively including type of disperser solvent and desorption solvent, rhamnolipid concentration, volume of disperser solvent, amount of magnetic nanoparticles, extraction time, desorption time, ionic strength, and sample pH. Under the optimized microextraction and gas chromatography with mass spectrometry conditions, the method demonstrated good linearity over the range of 0.5-500 µg/L with a coefficient of determination of R2 = 0.9904, low limit of detection (0.15 µg/L) and limit of quantification (0.50 µg/L) of bisphenol A, good analyte recoveries (84-120%) and acceptable relative standard deviation (1.8-14.9%, n = 6). The proposed method was successfully applied to three environmental water samples, and bisphenol A was detected in all samples

An efficient biosorption‐based dispersive liquid‐liquid microextraction with extractant removal by magnetic nanoparticles for quantification of bisphenol A in water samples by gas chromatography‐mass spectrometry detection

In this work, a simple, fast, sensitive, and environmentally friendly method was developed for preconcentration and quantitative measurement of bisphenol A in water samples using gas chromatography with mass spectrometry. The preconcentration approach, namely biosorption-based dispersive liquid-liquid microextraction with extractant removal by magnetic nanoparticles was performed based on the formation of microdroplet of rhamnolipid biosurfactant throughout the aqueous samples, which accelerates the mass transfer process between the extraction solvent and sample solution. The process is then followed by the application of magnetic nanoparticles for easy retrieval of the analyte-containing extraction solvent. Several important variables were optimized comprehensively including type of disperser solvent and desorption solvent, rhamnolipid concentration, volume of disperser solvent, amount of magnetic nanoparticles, extraction time, desorption time, ionic strength, and sample pH. Under the optimized microextraction and gas chromatography with mass spectrometry conditions, the method demonstrated good linearity over the range of 0.5-500 µg/L with a coefficient of determination of R2 = 0.9904, low limit of detection (0.15 µg/L) and limit of quantification (0.50 µg/L) of bisphenol A, good analyte recoveries (84-120%) and acceptable relative standard deviation (1.8-14.9%, n = 6). The proposed method was successfully applied to three environmental water samples, and bisphenol A was detected in all samples

Magnetic nanoparticles assisted dispersive liquid– liquid microextraction of chloramphenicol in water samples

This work describes the development of a new methodology based on magnetic nanoparticles assisted dispersive liquid–liquid microextraction (DLLME-MNPs) for preconcentration and extraction of chloramphenicol (CAP) antibiotic residues in water. The approach is based on the use of decanoic acid as the extraction solvent followed by the application of MNPs to magnetically retrieve the extraction solvent containing the extracted CAP. The coated MNPs were then desorbed with methanol, and the clean extract was analysed using ultraviolet–visible spectrophotometry. Several important parameters, such as the amount of decanoic acid, extraction time, stirring rate, amount of MNPs, type of desorption solvent, salt addition and sample pH, were evaluated and optimized. Optimum parameters were as follows: amount of decanoic acid: 200 mg; extraction time: 10 min; stirring rate: 800 rpm; amount of MNPs: 60 mg; desorption solvent: methanol; salt: 10%; and sample pH, 8. Under the optimum conditions, the method demonstrated acceptable linearity (R2 = 0.9933) over a concentration range of 50–1000 µg l–1. Limit of detection and limit of quantification were 16.5 and 50.0 µg l–1, respectively. Good analyte recovery (91–92.7%) and acceptable precision with good relative standard deviations (0.45–6.29%, n = 3) were obtained. The method was successfully applied to tap water and lake water samples. The proposed method is rapid, simple, reliable and environmentally friendly for the detection of CAP