The study investigated the effects of three reheating methods (water bath, stir-frying, and microwave) on the flavor of ginger duck, a traditional Chinese dish, using solid-phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS), high performance liquid chromatography (HPLC), electronic nose (E-nose), electronic tongue (E-tongue), and multivariate statistical analysis. The results showed that while the number of aroma compounds increased after reheating, their total content decreased. Stir-frying and microwave reheating produced the highest number of aroma compounds (77), whereas water bath reheating resulted in the lowest aroma loss and the highest content of volatile compounds. Principal component analysis of the E-nose data revealed that the aroma characteristics of water bath-reheated samples closely resembled those of fresh samples and were significantly different from those of stir-fried and microwaved samples. Partial least squares-discriminant analysis (PLS-DA) combined with odor activity values (OAVs) identified 11 key aroma compounds as differential markers. Taste analysis indicated a decrease in free amino acid contents and an increase in bitter nucleotide contents after reheating, while umami and sweet nucleotide contents remained largely unchanged. Glutamic acid, 5’-guanylic acid, 5’-inosinic acid, and 5’-adenylic acid contributed significantly to the taste, but PLS-DA showed no significant differences in their levels among reheating methods, resulting in similar taste profiles. These findings provide a scientific basis for quality control and reheating method selection in the industrial production of ginger duck.

This study aimed to identify the lipid composition and the positional distribution of fatty acids in dried shrimp and to select differential lipids and investigate lipid changes and the lipid transformation mechanism during storage using lipidomics analysis. Results showed that a total of 790 lipids belonging to 7 major classes were identified, among which glycerophospholipids were the most abundant, followed by glycerolipids and sphingolipids. In phosphatidylcholine (PC), phosphatidylethanolamine (PE), triglycerides (TG), and diglycerides (DG), saturated fatty acids were found to be mainly located at the sn-1 position, while unsaturated fatty acids, especially oleic acid, linoleic acid, docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), were mainly distributed at the sn-2 position. Using multivariate statistical analysis, 151 differential lipids were selected, 121 of which were up-regulated and the remaining 30 were down-regulated, indicating that storage had a significant effect on the types and contents of lipids in dried shrimp. After storage for 20 days, the relative contents of lyso-phosphatidylcholine, lyso-phosphatidylethanolamine, and lyso-phosphatidylserine in dried shrimp increased, and the relative contents of PC, PE, and phosphatidylserine decreased significantly, indicating the occurrence of lipid transformation.

The objective of the present study was to investigate the influence of cooking water on the taste characteristics of hand-grasped mutton. Hand-grasped mutton was made from mutton chops from Ningxia Yanchi Tan sheep with domestic water in Yanchi County, Ningxia; domestic water in Fengtai District, Beijing; or superpure water. The results showed that cooking water had a significant effect on the taste characteristics of hand-grasped mutton. The index of protein degradation and the contents of glutamic acid and 5’-inosinic acid in hand-grasped mutton made with superpure water were remarkably higher than those in the other two samples, while the contents of alanine and glycine in hand-grasped mutton made with Yanchi domestic water were markedly higher than in the other two samples. The umami intensity of hand-grasped mutton made with superpure water was the highest, while that of hand-grasped mutton made with Fengtai domestic water was the lowest. Collectively, the results of electronic tongue and sensory analysis indicated that there were significant differences in taste characteristics between the three samples of hand-grasped mutton, which was related to the types and contents of trace metal elements in cooking water.

In this study, the effect of Mg²⁺ on the physiochemical, structural and gel properties of mutton myofibrillar protein was studied. The results indicated that with an increase in Mg²⁺ concentration (0, 0.01, 0.02, 0.03, 0.04 and 0.05 mol/L), the physicochemical properties of mutton myofibrillar protein (MP) including solubility, emulsification activity, emulsion stability and particle size increased significantly (P < 0.05), the absolute value of the zeta potential decreased, the proportion of β-sheet increased significantly (P < 0.05), and surface hydrophobicity increased significantly (P < 0.05). The endogenous fluorescence intensity of tryptophan was largest at a Mg²⁺ concentration of 0.04 mol/L. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that the band intensity of myosin and relevant light chain proteins increased. Rheological analysis showed that the storage modulus (G’) first increased and then decreased. Compared with the control group, MP gel strength increased by 70.49% at a 0.03 mol/L Mg²⁺ concentration. Gel cooking loss and water-holding capacity (WHC) were negatively correlated with Mg²⁺ concentration (P < 0.05). Low-field nuclear magnetic resonance (NMR) analysis showed that with increasing Mg²⁺ concentration, immobilized water in the MP gel was transformed into free water. Microstructure observed by scanning electron microscopy (SEM) showed that the higher the concentration of Mg²⁺, the more porous the gel. Correlation analysis showed that Mg²⁺ concentration was highly correlated with the structure and gel characteristics of MP. Therefore, Mg²⁺ can significantly improve the gel properties of mutton MP.

In order to develop efficient preserving materials for meat products, sustained-release preservative composite films (CS-GEL-PE) were prepared by casting a mixed solution of chitosan (CS) and gelatin (GEL) added with different volume proportions (2%, 4%, 6% and 8%) of Pickering emulsion (PE) loaded with resveratrol (RES). The microstructure and physical properties of the films were determined by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and an intelligent electronic tensile testing machine, and antioxidant activity, sustained-release performance, and their preservation effect on prepared steak was analyzed. It was found that the addition of PE did not alter the structure of the CS-GEL film, increased its thickness, density, tensile strength, elongation at break, and antioxidant activity while conferring the composite film good sustained-release performance and significantly reducing its water content, solubility, swelling rate and water vapor permeability. The composite film with 6% PE (PE6) had the best overall performance. The preservation effect of the PE6 film combined with vacuum packaging on prepared steak was evaluated using vacuum packaging as a control. After 9 days of storage, the pH of the control group exceeded 6.7, the total volatile basic nitrogen (TVB-N) content was 20.28 mg/100 g, and the total bacterial count (TBC) was 6.37 (lg(CFU/g)), indicating that the steak was spoiled. In contrast, none of the pH, thiobarbituric acid reactive substances (TBARS) value, TVB-N content, and TBC of the PE6 group exceeded the limits, and the preservation effect of the PE6 film was better than the CS-GEL-RES film. In summary, the PE6 film has excellent mechanical properties and can prolong the shelf life of prepared steak.

The effects of different thermal sterilization processes on the volatile flavor substances of Zigong cold spicy beef were determined by headspace solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS). In four groups: control (unsterilized), T1 (100 ℃ for 10 min, 110 ℃ for 25 min, and 121 ℃ for 8 min), T2 (100 ℃ for 10 min, 115 ℃ for 20 min, and 121 ℃ for 5 min), and T3 (121 ℃ for 10 min), a total of 54 volatile flavor substances were detected. The total contents of volatile substances in the control, T1, T2 and T3 groups were 1280.11, 1338.30, 935.31 and 686.47 μg/kg, respectively. The most abundant substances in cold spicy beef were olefins, aldehydes, ketones and alcohols. According to their odor activity values (OAVs), linalool, decylaldehyde and nonylaldehyde were identified as the most significant contributors to the flavor. Principal component analysis (PCA) showed clear separation between the three treatment groups and the control group, T1 being the closest to the control group. Consistently, the results of electronic nose and sensory evaluation showed that the flavor of the T1 group was more similar to that of the control group because sulfur-containing compounds in the T2 and T3 groups contributed more to the flavor, and the difference between them was not significant (P > 0.05). In summary, compared with traditional sterilization, T1 provided better maintenance of the flavor of cold spicy beef.

In this study, chitosan (CS) and collagen (COL) composite nanoparticles were used as stabilizer to prepare Pickering emulsion loaded with resveratrol (PE-R). The particle size, potential, rheological properties, antibacterial effect, antioxidant properties and stability (centrifugal stability, storage stability, salt ion stability, pH stability) of PE-R were determined. According to the experimental results, PE60 (with 60% oil phase) was selected as the optimal one and used to prepare a preservative liner, which was placed in the bottom of the tray for the preservation of chilled beef. The results showed that the swelling rate and solubility of the PE60 liner were both significantly reduced, and this liner significantly slowed down the growth rates of thiobarbituric acid reactive substances (TBARS) value and total volatile basic nitrogen (TVB-N) content, inhibited the reproduction of microorganisms, reduced the centrifugal loss, better maintained the color, and extended the shelf life of beef from 6 to 10 days.