Poultry meat especially chicken meat is loved by consumers due to its high protein, low fat, low cholesterol, low calorie, and high nutritional value, and in recent years chicken meat has become the second most consumed meat after pork in China. As the broiler slaughter industry continues to develop, animal welfare is being taken increasingly seriously in China and pre-slaughter treatment of broilers is receiving growing attention. Stunning, as an important step in ensuring animal welfare, has a positive effect on reducing stress and improving meat quality in broilers. Electrical stunning is convenient, economical and requires little space, which is widely used in poultry slaughter lines. It can reduce carcass damage and pre-slaughter stress, reduce defective products, improve the quality of chicken meat and enhance its taste. Finding out suitable stunning parameters has been a focus of research for many years. This paper introduces different stunning methods for animals, reviews the current status of research on the effect of pre-slaughter electrical stunning on chicken meat quality, the factors affecting electrical stunning and the current status of domestic and international standardization of electrical stunning, analyzes the advantages and application of electrical stunning, and provides an outlook on future development, aiming to provide a reference for follow-up research and standard formulation.

To investigate the shelf life of eggs from different chicken breeds stored at various temperatures, Haugh unit, air cell depth, yolk index, albumen pH and mass loss of eggs from Jingfen 6 and Hy-Line Grey laying hens stored under refrigerated (4 ℃) or room temperature (25 ℃) conditions were examined. Taking Haugh unit below 60 as the end of shelf life, the shelf life of eggs from both breeds was found to be 12 and 83 days under ambient and refrigerated storage conditions, respectively. To develop prediction models for egg shelf life and storage time using back propagation artificial neural network (BP-ANN), Haugh unit, the most important indicator of egg freshness, was taken as an input parameter, and the other input parameters were selected based on the results of Pearson correlation analysis and used in descending order of correlation with Haugh unit. The specific input parameters were determined based on the performance of the models on the prediction set, and the BP-ANN models with optimized number of neurons in the hidden layer were compared with the other machine learning models partial least squares regression (PLSR) and support vector regression (SVR) models. The results showed that the BP-ANN models had higher accuracy in predicting the remaining shelf life and storage time of eggs compared to the PLSR and SVR models. This study provides a reference for determining the shelf life of eggs at different storage temperatures and technical support for the rapid, accurate and simultaneous prediction of the remaining shelf life and storage time.

The hurdle technology for food preservation effectively addresses the limitations of individual antimicrobial technologies by integrating their strengths. It can not only prolong the storage time of food but also maintains its high quality. In this study, three antimicrobial and bactericidal technologies, namely soluble gas stabilization (SGS), modified atmosphere packaging (MAP), and cold plasma (CP), were applied to chilled chicken breasts. The packaging, total viable count (TVC), and physicochemical properties of chilled chicken breasts after treatments and storage at 4 ℃ were monitored. The microbial diversity at the initial and end points of the storage time of each group was also analyzed. The results indicated that a 3-5 h SGS treatment can effectively increase the proportion of carbon dioxide in the MAP during the storage process of chilled chicken breasts, thereby alleviating the packaging collapse problem. Simultaneously, the effect of SGS, MAP, and CP combinational treatments significantly extended the storage time of chilled chicken breasts while maintaining the physicochemical qualities of samples. Compared to the control group, the TVC of chicken breast treated with SGS, MAP, and CP treatments decreased by 0.58 (lg(CFU/g)) at 0 day. The shelf life was extended by 5 days. After 8 days, the total volatile basic nitrogen (TVB-N) was 26.67 vs. 19.50 mg/100 g, thiobarbituric acid reactive substances (TBARS) was 0.99 vs. 0.72 mg MDA/kg, and TVC was 8.22 vs. 6.52 (lg(CFU/g)). High-throughput sequencing results showed that SGS and MAP treatments significantly reduce the proportion of Pseudomonas and Psychrobacter, which are sensitive to carbon dioxide, in the total bacterial genera. This study underscores the potential of integrating multiple antimicrobial technologies for effective food preservation.

Molecular dynamics can be one of the most promising simulations at the molecular level. Traditional experiments can also be restricted to low controlling precision, in order to directly observe the dynamic changes. It is very necessary to accurately explore the cell membranes in the formation of nanochannels. In this study, an innovative framework was introduced to simulate the molecular dynamics of cell membranes and nanochannel formation using molecular dynamics. Two steps were set as the initial construction of a 3D structural model and subsequent dynamic simulation. The real structure and composition of the cell membrane were considered for the closely resembled construction of the 3D model. The impedance parameters of samples were determined under various processing. The impedance amplitude and phase angle were selected as the indicators of electrical impedance. The 3D structural model was constructed to sensitively reflect the structure and function of the cell membrane. Furthermore, 15 frequency points were identified in the range of 0.05 to 300 kHz during measurement. A broad spectrum was spanned from the low to the high frequencies. The impedance amplitude and phase angle of meat samples were assessed before and after treatment. Comparative analysis revealed that the varying processing was significantly impacted on the integrity of the cell membrane. The evidence was from the changes in the impedance amplitude and phase angle. A 10 nm × 10 nm × 10 nm lipid bilayer structure model was constructed to further validate. The actual structure of the cell membrane was extracted to perform the molecular dynamics simulation. The overall structure of the lipid bilayer was evaluated during the simulation, including the density distribution, mean square displacement, and radial distribution function. The results indicated that the impedance amplitude of the sample decreased with the increasing electric field strength within experimental conditions, while the phase angle increased gradually. A stable configuration was maintained in the lipopolysaccharide and phospholipid layers in the cell membrane structure, in the absence of an electric field and high salt. No nanochannel structure was observed without any loosening or dissociation. Once an electric field of 4 kV/cm was applied, the nanochannel was outstandingly formed. As such, the significant effect of an electric field on the cell membrane structure, thus inducing the nanochannel formation. In the high-salt systems, the NaCl ions tended to preferentially traverse these nanochannels. The channel structure was then stabilized to enhance its stability. Furthermore, the 8% NaCl solution failed to disrupt the order and structural dimension of the cell membrane at physiological levels. Fortunately, the pulsed electric field was also introduced to accelerate the migration of lipid bilayer molecules. Ultimately, the nanochannels were formed to disrupt the integrity of the cell membrane. This degree of disruption was closely related to the strength of the electric field. Additionally, the NaCl solution also played a positive role in the porous structure and its stability in the high-salt system. These findings can provide an important basis for a better understanding of the molecular dynamics of cell membranes and the formation of nanochannels. The brining treatment can also be optimized to design the nanopores.

The changes in the pH, color, total bacterial count (TBC), total volatile basic nitrogen (TVB-N) content, malondialdehyde (MDA) content, sensory evaluation, and freshness (K value) of the breast muscle of yellow feathered broilers were measured during postmortem storage at 4 ℃. The results showed that according to pH and TBC, chicken breast meat samples stored for 0-3 and more than 3 days were identified as being fresh (pH < 6.7 and TBC < 6 (lg (CFU/g)) and stale (pH > 6.7 and TBC > 6 (lg (CFU/g)). According to sensory scores, the freshness of chicken breast meat stored for 0-4 and more than 4 days was acceptable (total sensory score > 60.00) and unacceptable (total sensory score < 60.00), respectively. According to K value, the corresponding time of the freshness of chicken breast meat was the day of slaughter (< 5%), as well as 1 (5%-15%), 2 (15%-20%), 3 (20%-25%), 4 (25%-30%), and 5 d (> 30%) after slaughter, and was graded into first, second, third, fourth, fifth grades of fresh and spoilage, respectively. Therefore, pH, TBC, sensory score and K value can reflect the freshness of chicken breast meat under short-term storage (within 5 days). The findings of this study can help determine the post-slaughter storage time and predict the shelf life of chicken breast meat.

The cold plasma (CP) technique was applied to alleviate the contamination of polycyclic aromatic hydrocarbon (PAH) in this investigation. Two different CP treatments methods were implemented in the production of beef patties, to investigate their inhibition and degradation capacity on PAHs. With 5 different cooking oils and fats addition, the inhibition mechanism of in-package cold plasma (ICP) pretreatment was explored from the aspect of raw patties fatty acids composition variation. The results of principal component analysis showed that the first two principal components accounted for more than 80% of the total variation in the original data, indicating that the content of saturated fatty acids was significantly positively correlated with the formation of PAHs. ICP pretreatment inhibited the formation of PAHs by changing the composition of fatty acids, which showed that the total amount of polyunsaturated fatty acids decreased and the total amount of monounsaturated fatty acids increased. Sensory discrimination tests demonstrated there were discernable differences between 2 CP treated samples and the controls, utilization of the ICP pretreatment in meat products processing was expected to achieve satisfying eating quality. In conclusion, CP treatment degraded PAHs through stepwise ring-opening oxidation in 2 reported pathways, the toxicity of PAHs contaminated products was alleviated after CP treatment.

The sensory perception of food is a dynamic process, which is closely related to the release of flavor substances during oral processing. It’s not only affected by the food material, but also subjected to the individual oral environment. To explore the oral processing characteristics of soft-boiled chicken, the sensory properties, texture, particle size, viscosity, characteristic values of electronic nose and tongue of different chicken samples were investigated. The correlation analysis showed that the physical characteristics especially the cohesiveness, springiness, resilience of the sample determined oral processing behavior. The addition of chicken skin played a role in lubrication during oral processing. The particle size of the bolus was heightened at the early stage, and the fluidity was enhanced in the end, which reduced the chewing time to the swallowing point and raised the aromatic compounds signal of electronic nose. But the effect of chicken skin on chicken thigh with relatively high fat content, was opposite in electronic nose, which had a certain masking effect on the perception of umami and sweet taste. In conclusion, fat played a critical role in chicken oral processing and chicken thigh had obvious advantages in comprehensive evaluation of soft-boiled chicken, which was more popular among people.