Yulong Bao

Electron beam irradiation (EBI) is used to treat cereals, but its effects on isolated proteins recovered after irradiation of intact paddy rice remain unclear. EBI of rice before protein extraction may affect the properties of the recovered protein fraction. Paddy rice from Zhongzao 39 (ZZ39) and Jia 67 (J67) was exposed to 0–20 kGy EBI before dehulling and alkaline protein extraction. Brown rice color and moisture were measured, and the resulting brown rice protein isolates (BRPIs) were characterized using physicochemical, microscopic, spectroscopic, and thermal methods. Grain color varied across treatments, whereas moisture values remained within a narrow range for each rice material. Aqueous protein solubility at pH 7.0 was low and generally decreased after irradiation. Hydrodynamic diameter and surface hydrophobicity showed patterns with variations across the tested dose levels, while the major reducing SDS-PAGE band positions were retained. Fitted amide I profiles, fluorescence intensities, and thermal-transition parameters also differed among treatments. These observations characterize proteins recovered after grain irradiation and subsequent extraction, precipitation, and freeze-drying. The two rice materials showed different descriptive response patterns. Overall, the findings identify changes that should be considered when recovering proteins from irradiated rice. EBI altered BRPI association and conformation without detectable shifts in surface potential or principal reducible subunit distribution. These findings supported the potential of EBI as a physical treatment for modulating brown-rice protein properties, provided that irradiation conditions are selected according to cultivar and the target quality attribute.

Citrus plants are vital, globally distributed medicinal and edible homologous resources with a long application history in traditional Chinese medicine (TCM) and modern functional food industries. Representative Citrus-derived medicinal and edible herbs including Citri reticulatae pericarpium (Chenpi), Citri grandis exocarpium (Huajuhong), Aurantii fructus immaturus (Zhishi), Aurantii fructus (Zhiqiao), and Citri reticulatae semen (Juhe) possess rich bioactive components and diverse pharmacological activities, laying a solid material foundation for their dual food and medicinal applications. This review systematically summarizes the traditional empirical processing and modern innovative processing technologies of typical Citrus medicinal and edible homologous herbs, and elaborates the dynamic variations in core phytochemicals induced by different processing methods and parameters. Combined with modern phytochemistry and pharmacological research, the core chemical transformation mechanisms during processing, including hydrolysis, oxidation, polymerization and isomerization, are clarified, scientifically interpreting the TCM processing theory of “processing modulates herbal efficacy”. Meanwhile, the current research limitations of Citrus processing research have been analyzed. On this basis, future research directions are proposed, aiming to provide systematic theoretical support and practical technical guidance for the standardized processing, quality optimization, rational utilization and industrial upgrading of Citrus medicinal and edible homologous resources, and promote the cross-integrated development of TCM processing theory and modern food science and pharmacology.

The impact of nonionic surfactant (Tween 20 and Tween 80) addition during the chopping process on the surimi gel quality was investigated. Results showed that the addition of Tween 20 or Tween 80 significantly decreased myofibrillar protein solubility in a dose-dependent manner. The surface hydrophobicity of myofibrillar proteins increased, likely due to the binding of surfactants. However, the added surfactants exerted a protective effect on myofibrillar protein denaturation, indicated by the greater intensity of intrinsic fluorescence and a higher proportion of ordered secondary structure. Forward-extrusion tests demonstrated that the surfactants reduced the cohesion and adhesion of the surimi paste, leading to improved uniformity and easier extrusion. For the heat-set surimi gel, addition of Tween 20 and Tween 80 led to a less compact, more porous microstructure, which ultimately led to reduced gel strength, hardness, and water-holding capacity. These findings showed that Tween 20 and Tween 80 can protect proteins against denaturation during chopping and improve the flowability of surimi paste, and the weakened mechanical strength of heat-set gel offered potential applications in developing specialized textured foods for the elderly.

Muscle-protein modification plays a critical role in determining the quality, functional properties, and nutritional value of meat and aquatic products. Over recent decades, non-thermal processing technologies including irradiation, cold plasma, high-pressure processing, ultrasound, and electromagnetic fields have been widely explored in muscle foods. This review aims to critically examine modifications of food proteins subjected to non-thermal processing, with a focus on literature within the last five years. The review first introduces the type and theory of physicochemical modifications of food proteins, which includes protein oxidation, changes in net charge, cross-linking and aggregation. Subsequently, characterization methods applicable to food proteins are briefly discussed. Finally, the effects of non-thermal processing on muscle proteins are thoroughly discussed. This review will elucidate the intricate mechanisms of protein modification in muscle-based products, providing a theoretical framework to drive the advancement of innovative non-thermal processing technologies.

Muscle protein modification plays a critical role in determining the quality, functional properties, and nutritional value of meat and aquatic products. Over recent decades, non-thermal processing technologies including irradiation, cold plasma, high-pressure processing, ultrasound, and electromagnetic fields have been widely explored in muscle foods. This review aims to critically examine modifications of food proteins subjected to non-thermal processing, with a focus on literature within the last five years. The review first introduces the type and theory of physicochemical modifications of food proteins, which includes protein oxidation, changes in net charge, cross-linking and aggregation. And then the corresponding characterization methods that can be used for food proteins were briefly covered. Finally, the effects of non-thermal processing on muscle proteins were thoroughly discussed. This review will shed light on the complicated mechanism of protein modifications in muscle foods and empower future development of non-thermal processing technologies in muscle foods.

Plasma-activated water (PAW) is an emerging disinfectant; however, its potential as a quorum sensing inhibitor (QSI) for biofilm control remains underexplored, and its action mechanisms have not been elucidated. This study investigated the effects of PAW on biofilm formation and spoilage factors secretion in Pseudomonas fluorescens under sub-inhibitory conditions. PAW generated by treating water for 60 s (PAW-60) reduced biofilm biomass by up to 1.29 log CFU/mL after 12 h incubation. It also completely inhibited protease production (100%) and decreased siderophore production by 31.87%. N-butyryl-homoserine lactone (C₄-HSL) was identified as the dominant signaling molecule, with its production decreasing by 34.34–84.07% following PAW treatments. Meanwhile, C₄-HSL activity was significantly suppressed by 42.58–65.38%. An FTIR analysis revealed the formation of a new C=O group, indicating oxidative degradation of acyl homoserine lactones (AHLs). Exogenous C₄-HSL progressively restored the biofilm biomass, spoilage factors production, and QS-related gene expression levels, with no significant difference observed compared with the control at 0.05 µg/mL (p < 0.05). The results suggest that the inhibitory effects of PAW are primarily due to the disruption of AHLs transduction in the QS pathway. Molecular docking showed that the long-lived reactive species in PAW could bind to AHLs’ synthetic protein (FadD1) and receptor protein (LuxR) via hydrogen bonding. PAW-60 reduced the spoilage activity of P. fluorescens inoculated into fish muscle juice and extended its shelf life from 8 to 10 days during storage at 4 °C. A strong positive correlation was observed between AHLs accumulation and the spoilage process. These findings demonstrate that PAW mitigates biofilm formation and food spoilage by blocking signaling transduction, which involves suppression of AHLs production, oxidative degradation of AHLs molecules, and disruption of AHLs recognition.

Plasma-activated water (PAW) is an emerging disinfectant, but few studies have explored its role as a quorum sensing inhibitor (QSI) for biofilm suppression, and the mechanisms of action remain unclear. Herein, we investigated the effects of PAW on biofilm formation and spoilage factors secretion in Pseudomonas fluorescens under sub-inhibitory conditions. The results showed that PAW-60 treatment achieved a maximum reduction of 1.29 log CFU/mL in P. fluorescens biofilm after 12 h incubation. Furthermore, PAW-60 completely inhibited protease production (100%) and decreased siderophore production by 31.87%. C4-HSL was identified as the dominant signaling molecule, and its production was reduced by 34.34% to 84.07% after selected PAW treatments. Meanwhile, C4-HSL activity was significantly decreased by 42.58% to 65.38% (P < 0.05). FTIR analysis detected the formation of a new C=O group after PAW treatment, indicating that PAW degraded AHLs by oxidative modification. Exogenous C4-HSL gradually restored biofilm biomass, spoilage factors production, and QS-related gene expression levels, implying that the inhibitory effects of PAW primarily resulted from the disruption of AHLs transduction. Molecular docking showed that long-lived reactive species in PAW could bind to AHLs synthetic protein (FadD1) and receptor protein (LuxR) via hydrogen bonding. PAW-60 treatment effectively reduced spoilage activity of P. fluorescens inoculated to fish muscle juice and extended its shelf life from 8 to 10 days during 4 °C storage. These findings revealed that PAW mitigated biofilm formation and the spoilage process of food by blocking signaling transduction, which involved AHLs production inhibition, degradation, and recognition disruption.

B vitamins are essential micronutrients that play crucial roles in various biochemical reactions, yet their stability in food systems is significantly affected by oxidation during processing and storage. This comprehensive review examines the complex interactions between B vitamin oxidation and other food components, particularly focusing on the underlying effect of lipid oxidation, protein oxidation, and Maillard reactions on B vitamin stability. The review systematically analyzes the oxidation mechanisms of eight B vitamins and their unique susceptibilities to different oxidative conditions. Special attention is given to the food matrix effects, including how changes in the oxidation status of food systems and alterations in matrix properties affect B vitamins' stability. The interplay between B vitamins and other food components is discussed from both chemical and physical perspectives, providing insights into how these interactions affect vitamin retention and bioavailability. Recent advances in understanding these complex relationships are highlighted, along with emerging strategies for vitamin preservation in food systems. This review synthesizes current knowledge about B vitamin oxidation in foods while identifying critical knowledge gaps and future research directions. The findings presented here have important implications for food processing, fortification, and storage strategies aimed at optimizing B vitamin retention in food products.