Impact of traditional halal meat production without stunning (NST) and commercial slaughter with electrical stunning (ST) of 100 slow-growing broiler chicken on blood plasma and different biochemical, enzymatic, hormonal, meat quality, and proteomic changes was evaluated. The results revealed lower (P < 0.05) postmortem pH values and higher redness (a*) scores for ST samples relative to NST group. Myofibrillar fragmentation index and bleeding efficiency (%) were lower (P < 0.05) in ST compared to NST samples. The ST group had higher (P < 0.05) creatinine, total protein, alanine aminotransferase (ALT), and triiodothyronine (T3) than NST group, however, no difference (P > 0.05) in blood glucose, lactate dehydrogenase (LDH), creatine kinase (CK), thyroxine (T4), cortisol, and aspartate aminotransferase (AST) was observed relative to NST samples. The 2-dimensional gel electrophoresis (2-DE) coupled to MALDI-TOF MS of meat samples has identified 14 differentially abundant proteins between 2 groups. Proteins demonstrating positive correlation with stress namely adenylate kinase isoenzyme-1, Rho guanine nucleotide exchange factor (NST), and apolipoprotein A-I (ST) were overabundant. From the current study, it is concluded that electrical stunning of broilers prior to slaughter or traditional halal slaughter without stunning does not adversely affect the meat quality.

The study investigated gelatin extraction from chicken skin-head-feet (SHF) blend using conventional and ultrasound-assisted methods with food-grade acetic and citric acids. Ultrasound pretreatment was introduced as an intervention in the extraction process, eliminating the need for alkali hydrolysis and significantly reducing the processing time. The gelatin yield, gel clarity, textural parameters, and functional properties were noticeably improved with ultrasound pretreatment. Higher (p< 0.05) solubility was observed in ultrasound-treated gelatin relative to traditionally extracted gelatin at different pH levels. Fourier Transform Infrared (FTIR) spectra revealed characteristic bands corresponding to Amide A, B, I, II, and III. Ultrasonication enhanced α-helical structure by reorganizing protein conformations and stabilizing α-helix regions. The rheological properties, gel strength, and viscosity significantly (p< 0.05) increased with ultrasound-assisted extraction. The SDS-PAGE profile of gelatin was compared with the commercial pork skin gelatin and found to possess two distinct α-chains (α1 and α2) and β chain. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry revealed the presence of collagen α1 and α2 chains as major components. This sustainable approach transformed poultry waste into a valuable resource, fostering the recovery of gelatin with improved functional attributes.

1. This study evaluated the suitability of routine analytical procedures and used mass spectrometry based proteomic approaches to distinguish meat from dead chicken/ cold slaughtered birds (CS), electrically stunned and slaughtered birds, as per standard protocols (ES), and birds slaughtered according to halal guidelines (HS).2. Meat from CS birds had lower (P < 0.05) pH, water holding capacity and higher (P < 0.05) lipid oxidation, haem iron content, residual blood and total viable counts relative to ES and HS meat indicating poor quality.3. The results demonstrated the presence of unique protein bands on SDS-PAGE only in CS meat that can be used for routine screening.4. Protein analysis using MALDI-TOF mass spectrometry has identified haemoglobin subunit alpha-A and alpha-D; Adenylate kinase isoenzyme 1 as reliable and stable marker proteins for authentication of dead chicken meat under raw and cooked conditions and halal slaughtered chicken, respectively.5. The methods used may be employed by the food safety and regulatory agencies for regular screening of meat quality and to authenticate CS or HS chicken.