Mohsen Dalvi-Isfahan

Lime ( Citrus aurantiifolia ) is a nutrient‐rich citrus fruit with high antioxidant potential but a limited shelf life due to physiological and microbial deterioration. This study explores the efficacy of cold plasma (CP) pretreatment, including dielectric barrier discharge (DBD) and gliding arc (GLIDE) plasma, in enhancing the antioxidant properties and storage stability of lime fruit. The results demonstrate that CP treatment significantly influences key bioactive compounds, including vitamin C, total phenolics, flavonoids, and tannins, particularly in the peel. DBD plasma at 10 min exhibited the most pronounced enhancement of antioxidant compounds. Fourier‐transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses revealed surface chemical modifications and structural changes induced by CP, affecting enzymatic activity and bioactive compound release. Antioxidant activity exhibited a biphasic trend, with initial declines followed by a recovery phase, particularly in CP‐treated samples. These findings suggest that CP treatment, particularly DBD plasma, enhances the antioxidant profile of lime while extending its postharvest stability. The study highlights CP as a promising, nonchemical alternative for improving the nutritional properties of citrus fruits. Further optimization of plasma parameters could enhance commercial applications.

This study investigates the effects of headspace conditions (absence of headspace, full air, and full steam) and product viscosity (Brix values of 18 and 28) on the thermal processing of canned tomato paste. The results show that the presence of an air layer within the can's headspace significantly influences the temperature profile and the location of the slowest heating zone (SHZ), without markedly affecting the overall temperature magnitude. The Brix values, which indicate the paste's viscosity, are found to be crucial factors in heat transfer, with lower Brix values promoting convection and higher values favoring conduction. The average velocity for Brix 18 was approximately 10 times higher than that for Brix 28. Among the three main color parameters, the a* index experienced the most significant changes (maximum drop of 67%), while the b* index showed the least variation (maximum drop of 22%) during processing. The time required to reduce the number of bacteria to 10⁻⁶ CFU/g at the cold point of tomato paste cans was 28% higher in the product with Brix 18 compared with Brix 28. These findings underscore the importance of considering headspace conditions and product viscosity to optimize thermal processing methods, thereby enhancing the safety and quality of canned tomato products.

This study investigated the effects of microwave-assisted freezing on the quality attributes of button mushrooms (Agaricus bisporus). Four levels of microwave power (0, 10, 20, 30%) were applied to the mushroom samples during freezing. The quality attributes of the frozen and thawed mushrooms were then evaluated. The results suggested that higher microwave power produced the smaller and more uniform ice crystals. Moreover, the browning index of the mushroom samples increased with increasing microwave power. The textural properties (hardness) of the mushrooms were also affected by the microwave power, showing higher values as the power increased. Furthermore, the ratio of the microwave operating system’s power to the freezer power was low and approximately 20% at the highest power level. Therefore, these findings confirm the potential of microwave-assisted freezing for reducing freeze damage to mushroom tissue and, thus, provide frozen mushroom with a better texture.