Oxidation induced by dielectric barrier discharge (DBD) plasma treatment reduces IgG/IgE binding capacity and improves the functionality of glycinin

Investigation into potential allergenicity of DBD plasma-treated casein digestion products based on immunoglobulin E linear epitopes and the sensitized-cell model

The study aimed to investigate the allergenicity change in casein treated with dielectric barrier discharge (DBD) plasma during in vitro simulated digestion, focusing on the immunoglobulin E (IgE) linear epitopes and utilizing a sensitized-cell model. Results indicated that prior treatment with DBD plasma treatment (4 min) before simulated digestion led to a 10.5% reduction in the IgE-binding capacity of casein digestion products. Moreover, the release of biologically active substances induced from KU812 cells, including β-HEX release rate, human histamine, IL-4, IL-6, and TNF-α, decreased by 2.1, 28.1, 20.6, 11.6, and 17.3%, respectively. Through a combined analysis of LC-MS/MS and immunoinformatics tools, it was revealed that DBD plasma treatment promoted the degradation of the IgE linear epitopes of casein during digestion, particularly those located in the α-helix region of αs1-CN and αs2-CN. These findings suggest that DBD plasma treatment prior to digestion may alleviate casein allergic reactions.

Insights into Cold Plasma Treatment on the Cereal and Legume Proteins Modification: Principle, Mechanism, and Application

Cereal and legume proteins, pivotal for human health, significantly influence the quality and stability of processed foods. Despite their importance, the inherent limited functional properties of these natural proteins constrain their utility across various sectors, including the food, packaging, and pharmaceutical industries. Enhancing functional attributes of cereal and legume proteins through scientific and technological interventions is essential to broadening their application. Cold plasma (CP) technology, characterized by its non-toxic, non-thermal nature, presents numerous benefits such as low operational temperatures, lack of external chemical reagents, and cost-effectiveness. It holds the promise of improving proteins' functionality while maximally retaining their nutritional content. This review delves into the pros and cons of different cold plasma generation techniques, elucidates the underlying mechanisms of protein modification via CP, and thoroughly examines research on the application of cold plasma in augmenting the functional properties of proteins. The aim is to furnish theoretical foundations for leveraging CP technology in the modification of cereal and legume proteins, thereby enhancing their practical applicability in diverse industries.

Preventing thermal aggregation of ovalbumin through dielectric-barrier discharge plasma treatment and enhancing its emulsification properties

The impact of Dielectric-Barrier Discharge (DBD) plasma treatment on the prevention of heat-induced aggregation of Ovalbumin (OVA) and improvement in emulsification properties was investigated. Results highlighted the effective inhibition of thermal aggregation of OVA following exposure to plasma. Structural analysis revealed that the plasma-induced oxidation of sulfhydryl and intermolecular disulfide bonds played a pivotal role in inhibiting the thermal aggregation, considered by Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE), multiplies spectroscopy, and analysis of dynamic exchange of sulfhydryl-disulfide bonds. Meanwhile, the oxidation of exposed hydrophobic sites due to plasma treatment resulted in the transformation of the OVA molecule's surface from hydrophobic to hydrophilic, contributing significantly to the aggregation inhibition. Additionally, compared to an untreated sample of OVA, almost one-fold increase in emulsifying ability (EAI) and 1.5-fold in emulsifying stability (ESI) was observed after 4 min of plasma treatment. These findings demonstrated that plasma treatment not only enhanced the thermal stability of OVA, but also improved its emulsification properties.

Efficacy of cold plasma technology on the constituents of plant-based food products: Principles, current applications, and future potentials

Cold plasma (CP) is one of the novel non-thermal food processing technologies, which has the potential to extend the shelf-life of plant-based food products without adversely affecting the nutritional value and sensory characteristics. Besides microbial inactivation, this technology has been explored for food functionality, pesticide control, and allergen removals. Cold plasma technology presents positive results in applications related to food processing at a laboratory scale. This review discusses applications of CP technology and its effect on the constituents of plant-based food products including proteins, lipids, carbohydrates, and polar and non-polar secondary plant metabolites. As proven by the publications in the food field, the influence of CP on the food constituents and sensory quality of various food materials are mainly based on CP-related factors such as processing time, voltage level, power, frequency, type of gas, gas flow rate as well as the amount of sample, type, and content of food constituents. In addition to these, changes in the secondary plant metabolites depend on the action of CP on both cell membrane breakdown and increase/decrease in the scavenging compounds. This technology offers a good alternative to conventional methods by inactivating enzymes and increasing antioxidant levels. With a waterless and chemical-free property, this sustainable and energy-efficient technology presents several advantages in food applications. However, scaling up CP by ensuring uniform plasma treatment is a major challenge. Further investigation is required to provide information regarding the toxicity of plasma-treated food products.

Current and Potential Applications of Atmospheric Cold Plasma in the Food Industry

The cost-effectiveness and high efficiency of atmospheric cold plasma (ACP) incentivise researchers to explore its potentials within the food industry. Presently, the destructive nature of this nonthermal technology can be utilised to inactivate foodborne pathogens, enzymatic ripening, food allergens, and pesticides. However, by adjusting its parameters, ACP can also be employed in other novel applications including food modification, drying pre-treatment, nutrient extraction, active packaging, and food waste processing. Relevant studies were conducted to investigate the impacts of ACP and posit that reactive oxygen and nitrogen species (RONS) play the principal roles in achieving the set objectives. In this review article, operations of ACP to achieve desired results are discussed. Moreover, the recent progress of ACP in food processing and safety within the past decade is summarised while current challenges as well as its future outlook are proposed.

Evaluating the influence of cold plasma bubbling on protein structure and allergenicity in sesame milk

BACKGROUND

Sesame is a traditional oilseed comprising essential amino acids. However, the presence of allergens in sesame is a significant problem in its consumption; thus, this study attempted to reduce these allergens in sesame oilseeds.

OBJECTIVE

The present study aimed to evaluate the effect of cold plasma processing on structural changes in proteins, and thereby the alteration of allergenicity in sesame milk. Method: Sesame milk (300 mL) was processed using atmospheric pressure plasma bubbling unit (dielectric barrier discharge, power: 200 V, and airflow rate: 16.6 mL/min) at different exposure times (10, 20, and 30 min).

RESULTS

The efficiency of plasma-bubbling unit as measured by electron paramagnetic resonance in terms of producing reactive hydroxyl (OH) radicals proved that generation of reactive species increased with exposure time. Further, the plasma-processed sesame milk subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and differential scanning calorimetery analysis revealed that plasma bubbling increased the oxidation of proteins with respect to bubbling time. The structural analysis by Fourier transform infrared spectroscopy and circular dichroism revealed that the secondary structure of proteins was altered after plasma application. This change in the protein structure helped in changing the immunoglobulin E (IgE)-binding epitopes of the protein, which in turn reduced the allergen-binding capacity by 23% at 20-min plasma bubbling as determined by the sandwich-type enzyme-linked immunosorbent assay. However, 30-min plasma bubbling intended to increase allergenicity, possibly because of increase in IgE binding due to the generation of neo epitopes.

CONCLUSION

These changes proved that plasma bubbling is a promising technology in oxidizing protein structure, and thereby reducing the allergenicity of sesame milk. However, increase in binding at 30-min bubbling is to be studied to facilitate further reduction of the binding capacity of IgE antibodies.

Influence of mild oxidation induced through DBD-plasma treatment on the structure and gelling properties of glycinin

The effects of dielectric-barrier discharge (DBD) plasma treatment (20 s to 120 s treatment time with 40 kV, 12 kHz) induced mild oxidation on the gelling properties, and related structural changes of glycinin were investigated. The gelling ability of glycinin was improved by the mild oxidation induced by the plasma treatment. Treated glycinin gels exhibited a continuous and uniform network microstructure. Samples treated for 120 s had a 2.07-, 3.99- and 2.03-fold increase in hardness, chewiness, and resilience compared to the 20 s treated samples. Structural analyses showed that primary and secondary structures of glycinin were unaffected. The tertiary structure was shifted, accompanied by a decrease in free sulfhydryl (-SH) content. At the same time, carbonyl content and average particle diameter were increased by DBD treatment. The DBD treatment facilitated the generation/exchange of intermolecular disulfide bonds and enhanced gelling properties of glycinin. It is concluded that controlled plasma-induced protein oxidation can improve protein functionality.

Impacts of Cold Plasma Technology on Sensory, Nutritional and Safety Quality of Food: A Review

As an emerging non-thermal food processing technology, cold plasma (CP) technology has been widely applied in food preservation due to its high efficiency, greenness and lack of chemical residues. Recent studies have indicated that CP technology also has an impressing effect on improving food quality. This review summarized the impact of CP on the functional composition and quality characteristics of various food products. CP technology can prevent the growth of spoilage microorganisms while maintaining the physical and chemical properties of the food. It can maintain the color, flavor and texture of food. CP can cause changes in protein structure and function, lipid oxidation, vitamin and monosaccharide degradation, starch modification and the retention of phenolic substances. Additionally, it also degrades allergens and toxins in food. In this review, the effects of CP on organoleptic properties, nutrient content, safety performance for food and the factors that cause these changes were concluded. This review also highlights the current application limitations and future development directions of CP technology in the food industry. This review enables us to more comprehensively understand the impacts of CP technology on food quality and promotes the healthy application of CP technology in the food industry.