This study investigated the quality and microbial flora changes of Lentinu edodes during postharvest cold storage. L. edodes was picked with sterile gloves, treated with ozone and stored for up to 40 days at 2–4 ℃. The changes in the moisture content, color, texture, and volatile flavor substance, free amino acid and flavor nucleotide contents of the mushroom were determine during the storage period, and the changes in the microbial flora on the surface of L. edodes were detected by high-throughput sequencing. Besides, fungi were isolated and identified from the mushroom surface, and the dominant spoilage organisms were determined. The results showed that the moisture content, brightness (L* value) and hardness decreased with storage time, while the elasticity, chewiness, cohesiveness and gumminess increased first and then decreased. The relative contents of alcohols contributing to the clean aroma of L. edodes such as 1-octene-3-ol and 3-octanol increased first and then decreased during storage, and so did the contents of umami, sweet and bitter amino acids. The contents of 5’-cytidine monophosphate (5’-CMP), 5’-uridine monophosphate (5’-UMP) and 5’-guanosine monophosphate (5’-GMP) decreased continuously, while the contents of inosine 5’-monophosphate (5’-IMP) and adenosine 5’-monophosphate (5’-AMP) increased first and then decreased. The richness of the microbial community decreased first and then increased, whereas the diversity increased first and then decreased. Pseudomonas was found to be the dominant spoilage bacteria. The major spoilage fungi were Trichoderma harzianum, Alternaria and Aspergillus flavus. In conclusion, the quality and microbial flora of L. edodes changed obviously during postharvest cold storage, which will provide a theoretical basis for further controlling the spoilage and prolonging the storage period of L. edodes.

In order to improve the bioavailability of resveratrol (Res), resveratrol was encapsulated in recombinant human heavy-chain ferritin (rHuHF) by ultrasonic treatment. rHuHF-Res were characterized, the interaction between Res and rHuHF was analyzed, and the antioxidant properties of rHuHF-Res were evaluated in simulated gastrointestinal juices. The results showed that approximately 22 resveratrol molecules could be encapsulated in one ferritin molecule with an encapsulation efficiency of 11.25%. Transmission electron microscopicy (TEM) results showed that resveratrol was encapsulated into the cavity of ferritin. The particle size of rHuHF-Res composites was not different from that of rHuHF as when detected by a laser particle size analyzer. The cavity of ferritin could protect Res from photothermal degradation. The results of ultraviolet visible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, fluorescence spectroscopy and circular dichroism (CD) spectroscopy showed that ferritin and resveratrol could interact through hydrogen bonds and other forces. After digestion, the superoxide anion radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity of the composites were significantly higher than those of resveratrol (P < 0.05). The ferritin-resveratrol nanoparticles have good photothermal stability and antioxidant property, which provides a certain theoretical basis for its future development and utilization.

In this study, a water-in-oil-in-water (W₁/O/W₂) multiple emulsion stabilized by dextran-ferritin-resveratrol (Dex-rHuHF-Res) nanoparticles was prepared by a two-step emulsification method. Its stability and potential for the delivery of bioactive substances were analyzed. The results showed that when the concentration of polyglycerol ricinoleate (PGPR) was 7% (V/V), the ratio of aqueous phase (W₁) to oil phase (O) was 3: 7, and the ratio of W₁/O to outer aqueous phase (W₂) was 4: 6, the emulsion had homogeneous appearance, uniform droplet size distribution, the smallest particle size (472 nm), and the highest apparent viscosity and storage modulus (G’). At pH 7, 100 mmol/L NaCl concentration and low centrifugal force, the emulsion maintained good stability. In unfavorable environment, compared with free chlorogenic acid, astaxanthin and resveratrol, the retention rates of chlorogenic acid, astaxanthin and resveratrol loaded in the multiple emulsion were significantly improved (P < 0.05). The bioaccessibilities of chlorogenic acid, astaxanthin, and resveratrol loaded in the W₁/O/W₂ emulsion were significantly increased (P < 0.05), and the antioxidant property of the emulsion was obviously enhanced (P < 0.05). This study provides a theoretical basis for the application of the W₁/O/W₂ emulsion stabilized by Dex-rHuHF-Res nanoparticles in the delivery of active substances.

In order to develop and utilize Lentinus edodes protein, the effect of glutamine transaminase (TGase) crosslinking on the physicochemical and processing characteristics of L. edodes protein was studied. The results showed that the addition of 0%–20% TGase gradually reduced the contents of total thiol, free thiol and β-sheet of L. edodes protein, while the fluorescence intensity, particle size, β-turn content and surface hydrophobicity showed a trend of initially increasing and then decreasing. As the shear rate increased, the shear stress of the protein increased and the apparent viscosity decreased, indicating that TGase cross-linking promoted the generation of macromolecular polymers. In addition, the cross-linked protein exhibited a dense texture similar to that of the original protein, indicating the formation of a stable three-dimensional network structure. As the addition level of TGase increased from 4% to 12%, the protein network structure became increasingly dense. Moreover, an appropriate amount of TGase significantly improved the solubility, emulsifying properties, thermal stability, and oil-holding capacity of L. edodes protein. These results indicate that TGase cross-linking improves the physicochemical and processing properties of L. edodes protein to varying degrees.