The taste quality of ready-to-eat rice is influenced by the uniformity of temperature distribution during microwave reheating. The temperature distribution uniformity of ready-to-eat rice loaded in a rectangular lunch box is investigated under microwave reheating. The results show that with a 10–80 °C temperature increase in the ready-to-eat rice, the thermal conductivity increases, dielectric constant, and specific heat increase and then decrease, while the dielectric loss factor decreases and then slightly increases. The microwave-heating process of ready-to-eat rice exhibits a clear ‘corner effect’, and the observed ‘hot spot’ results in poor temperature uniformity in ready-to-eat rice. A metalized packaging structure design is subsequently proposed to ameliorate the temperature non-uniformity. According to comparative results of four metalized packaging forms, the spray film volume and film thickness corresponding to film volume are developed as $3.5\times {10}^{-4}$ mL/${\mathrm{m}\mathrm{m}}^2$, 0.30 mm, respectively, which levels off the difference in temperature to improve the temperature distribution uniformity of ready-to-eat rice by microwave reheating.

Microwave energy utilization undergoes two stages via absorption and conversion inside ready-to-eat rice (RER) under microwave reheating. The reasonable utilization of microwave energy inside the processed material may enhance the uniformity of the temperature distribution. To analyze the uniformity changes inside RER, the effects of microwave reflection, refraction, and absorption by a metal aluminum film were studied through the thermodynamic properties. A simulation model was developed using the co-simulation method of COMSOL Multiphysics with MATLAB programming to analyze the mechanism of material properties and electromagnetic distribution on temperature distribution uniformity, as well as the formation mechanism of the temperature distribution uniformity of microwave-reheated RER. Based on models of the designed package boxes covering the metal film, the optimal structure was developed to include a metal aluminum film with a width of 5 mm and a thickness of 0.30 mm, which was sprayed on the edges and corners of a rectangular packaging box. The packaging boxes covering the metal films may reduce the average temperature of the upper and lower layers in RER by 8.03 °C and 7.42 °C, respectively, while the temperature distribution uniformity increased by 35.71% and 72.22%. The introduction of a metalized package significantly enhances the temperature uniformity inside RER under microwave reheating.

In order to investigate the effect of protein structure changes on the texture of scallop adductor muscles under ultra-high pressure, the protein structure, hardness, elasticity, cohesion, and chewing properties of untreated scallops maintained at 200 MPa for 60 s, 120 s, and 180 s were measured and compared. At the same time, sensory indicators were evaluated to verify the effect of ultra-high pressure treatment on the quality of scallop adductor muscles. The results indicated that the mass fraction of the α-helix was decreased by 13.70% and the mass fraction of β–folding was 2.72 times higher in the adductor muscle of scallops compared to the fresh adducts without ultra-high pressure treatment, maintained for 180 s at an ultra-high pressure of 200 MPa. At the same time, the value of I₈₅₀/I₈₃₀ of protein tyrosine residues was 1.094, which weakened the water retention ability of the protein, the elasticity of the scallop adduct was reduced from the original 7.16 N to 6.17 N, the cohesion was reduced by 3.76%, and the hardness was increased by 17.45%. This improved the cooking quality of scallops, which was consistent with the sensory evaluation results. Therefore, under ultra-high pressure treatment, changes in the protein structure of the adductor muscle of scallops had a certain impact on their texture, which was able to provide support for in-depth research on the mechanism of ultra-high pressure action.

Traditional drying methods often result in significant loss of flavor, color, and bioactive components in food products. One effective method of improving the nutritional value of foods and shortening the drying process is to apply heat via continuous microwave drying. Understanding continuous microwave drying of crab apples is key to boosting efficiency and energy savings. In this study, crab apple slices were dried under continuous microwave drying and thoroughly investigated in terms of dehydration characteristics and quality attributes. The effects of drying conditions, including slice thickness (1–5 mm), microwave power (11400–19000 W), air velocity (0–2 m/s), and drying time (12–16 min) on the changes in temperature, moisture content, color, texture, total phenolic content, and microstructure were analyzed. Results showed that increased microwave power and decreased slice thickness significantly reduced moisture content; increasing air velocity reduced the temperature increase, whereas prolonging drying time decreased moisture content and increased drying temperature. As the slice thickness increased, the color values showed a decreasing trend while texture and total phenolic content increased. The application of higher microwave power resulted in changes in the overall color and texture, which decreased while the total phenolic content increased, additionally damaging the surface structure. Higher air velocity increased the color and texture while reducing the total phenolic content. Moreover, heightened air velocity may lead to more apparent structural changes. As the drying time increased, the color and hardness values decreased while the total phenolic content increased; prolonged drying times can significantly change the microstructure. To ensure the quality of the dried product, it is recommended that high microwave power, excessive air velocity, and extended drying times be avoided. Therefore, the appropriate conditions for continuous microwave drying of crab apple slices are a slice thickness of 1.5 mm, microwave power of 15200 W, air velocity of 0.5 m/s, and drying time of 13 min. This study may offer guidance for understanding and improving the continuous microwave drying of dried products, such as crab apples.