Effect of electron beam irradiation on the structural characteristics and functional properties of goat's milk casein.

The effects of electron beam irradiation (EBI) at different doses (0, 2, 4, 6, 8, and 10 kGy) were investigated on the structural and functional properties of casein, including their interrelationship. A gradual reduction in the α-helix content of the secondary structure (as a stable structure) indicates that casein under EBI treatment mainly undergoes fragmentation and aggregation from a structural perspective. Furthermore, the hydrophobic group and tryptophan in the tertiary structure were exposed, which opened up the internal structure of the protein. In addition, a continuously increasing irradiation dose led to casein aggregation, as confirmed by electron microscopy. The structural changes affected its functional properties, such as solubility, emulsification, foaming, and rheological properties, all of which increased first and subsequently decreased. Finally, at irradiation doses of 4-6 kGy, casein was modified to exhibit optimal functional properties, which enhanced its food processing value and performance.

Electron beam irradiation induced aggregation, structural and functional changes of soybean 11S globulin.

This study investigated the effects of different irradiation doses of an electron beam (e-beam) (0, 2, 4, 6, 8, and 10 kGy) on the structure, emulsification, foaming, and rheological and gel properties of soybean 11S globulin. The irradiation treatment at 4 and 6 kGy significantly increased the solubility, surface hydrophobicity, disulfide bonding, and ζ-potential of 11S globulin, decreased the particle size of the protein solution, and effectively improved the emulsifying activity and foaming stability of the protein solution. Moreover, irradiation induced moderate cross-linking and aggregation of the proteins, thereby increasing the apparent viscosity and shear stress of the protein solution. In addition, the low-field NMR and microstructure analysis results revealed that protein gels formed a dense and homogeneous three-dimensional mesh structure after irradiation (6 kGy), along with increased content of bound water (T2b) and water not readily flowable (T21) and a decrease content of free water (T22). Overall, our results confirmed that e-beam irradiation could significantly improve the physicochemical properties of soybean 11S globulin. Our study thus provides a new technical means for the application of electron beam irradiation technology toward protein modification and broadens the high-value utilization of soybean 11S globulin in the food processing industry.

Chitosan/konjac glucomannan bilayer films: Physical, structural, and thermal properties.

To overcome the limitations of chitosan (CS) and konjac glucomannan (KGM), the bilayer films of CS and KGM were prepared by layer-by-layer (LBL) casting method, and the effects of different mass ratios (i.e., C5: K0, C4:K1, C3:K2, C1:K1, C2:K3, C1:K4, and C0:K5) on the microstructures and physicochemical properties of bilayer films were examined to evaluate their applicability in food packaging. The results revealed that the bilayer films had uniform microstructures. When compared with pure films, the bilayer films displayed lower swelling degrees and water vapor permeability. However, the tensile tests revealed a reduction in the mechanical properties of the bilayer films, which was nonetheless superior to that of the pure KGM film. In addition, the intermolecular interactions between the CS and KGM layers were observed through FTIR and XRD analyses. Finally, TGA and DSC analyses demonstrated a decrease in the thermal stability of the bilayer films. Our cumulative results verified that CS-KGM bilayer films may be a promising material for use in food packaging and further properties of the bilayer films can be supplemented in the future through layer-by-layer modification and the addition of active ingredients.

Evaluation of effects of ultrasound-assisted curing on the flavor of Chinese bacon.

The curing stage is of great importance in flavor formation during Chinese bacon processing. Ultrasound-assisted curing plays an essential role in the Lipid oxidation of meat products. In this study, GC-MS and electronic nose were used to analyze the influence of different power ultrasonic-assisted curing on the flavor formation of Chinese bacon. Through the analysis of phospholipid and lipase, the fundamental precursors of ultrasonic on the flavor of Chinese bacon were determined. It was found that there were differences in the flavor contour description of Chinese bacon between the ultrasonic treatment group, mainly due to the change in the W1W sensor. A total of 28 volatile compounds were detected by GC-MS, and the aldehyde content increased with ultrasonic power. PC and PE are the main flavor precursors in the curing process. This study provides a theoretical basis for improving the curing technology of Chinese bacon.

The Effect of Optimized Ultrafiltration on Perioperative Pulmonary Function During Cardiopulmonary Bypass in Infants Under 10 kg.

Objective: This study aims to investigate the effect of optimized ultrafiltration on perioperative electrolytes, acid-base balance, and pulmonary function during cardiopulmonary bypass (CPB) in infants with low body weight (under 10 kg), using traditional balanced ultrafiltration and modified ultrafiltration. Methods: A total of 30 children who underwent surgical correction for congenital heart disease in Changzhou Children's Hospital between January 2018 and December 2019 were randomly divided into two groups. In the treatment group, ultrafiltration pre-treatment was carried out with blood-containing priming fluid prior to CPB. Balanced ultrafiltration was performed during the operation, and optimized and modified ultrafiltration were conducted before closing and extubation. In the control group, traditional balanced ultrafiltration was used during the operation, and a modified ultrafiltration combination was used before closing and extubation. Indexes such as blood gas analysis and electrolytes were measured perioperatively, and pulmonary function was observed. Results: No deaths were reported in either group. The ventilator-assisted breathing time was shorter in the treatment group than in the control group (P < 0.05). The indexes of the treatment group were closer than those of the control group to the optimal physiological values. The concentrations of potassium ion (K+), lactate (Lac), and blood glucose (Glu) decreased, and there was significant difference between the two groups (P < 0.05) at the end of CPB. Hemoglobin (Hb) and hematocrit (HCT) in the treatment group increased (P < 0.01). Alveolar-arterial differences for oxygen (A-aDO2) and respiratory index (RI) increased significantly in both groups after operation. Children in the treatment group began to recover lung function earlier than children in the control group. Both A-aDO2 and RI were lower in the treatment group than in the control group at each time point after operation (P < 0.05). Conclusion: Optimizing and modifying the traditional ultrafiltration combination method can effectively shorten the ultrafiltration time, reduce the adverse impacts of the ultrafiltration technique, and improve the lung function of infants after operation.