Cold plasma processing effect on cashew nuts composition and allergenicity

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.

Mechanism of Cold Plasma Combined with Glycation in Altering IgE-Binding Capacity and Digestion Stability of Tropomyosin from Shrimp

Tropomyosin (TM) is a major crustacean allergen, and the present studies have tried to reduce its allergenicity by processing technologies. However, most research stopped on the allergenicity and structure of allergens, while information about epitopes was less. In this study, we first investigated the effects of cold plasma (CP) combined with glycation (CP-G) treatment on the processing and trypsin cleavage sites of TM from shrimp (Penaeus chinensis). The results showed a significant reduction in the IgE-binding capacity of TM after CP-G treatment, with a maximum reduction of 30%. This reduction was associated with the combined effects: modification induced by CP destroyed the core helical structure (D137 and E218) and occupied the potential glycation sites, leading to sequent glycation on conserved areas of TM, especially the epitope L130-Q147. Additionally, CP-G treatment decreased the digestion stability of TM by increasing the number of cleavage sites of trypsin and improving the efficiency of some sites, including K5, K6, K30, and R133, resulting in a lower IgE-binding capacity of digestion products, which fell to a maximum of 20%. Thus, CP-G is a valuable and reliable processing technology for the desensitization of aquatic products.

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.

Effects of dielectric barrier discharge cold plasma on structure, surface hydrophobicity and allergenic properties of shrimp tropomyosin

Effects of dielectric barrier discharge (DBD) cold plasma (CP) on structure, surface hydrophobicity and allergenic properties of tropomyosin (TM) in shrimp were investigated in this study. Results showed that the molecular weight of TM increased and the protein concentration decreased with CP treatment time increased. The content of free amino acids was increased by 74.7 % and the distribution of aromatic amino acids was altered. The content of α-helix was decreased by 69 % and the surface hydrophobicity increased by 57.8 % after 20 min treatment. Allergenicity analysis showed that the IgE binding capacity decreased by 96 % after 20 min treatment, and the degranulation indexes of KU812 cells like the β-HEX release rate, the intracellular calcium ion intensity, the release of histamine and inflammatory cytokines (IL-4, TNF-α) were decreased by 32.5 %, 31.0 %, 37.3 %, 51.7 %, and 70.2 %, respectively. The current study confirmed that DBD CP could reduce the TM allergenicity through structural changes.

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 Dielectric Barrier Discharge Cold Plasma Treatment on Starch, Gelatin, and Bacterial Cellulose Biodegradable Polymeric Films

The environmental damage caused by plastic packaging and the need to reduce pollution requires actions to substitute plastic materials for more sustainable and biodegradable materials. Starch, gelatin, and bacterial cellulose films are three potential biodegradable polymeric films for use in packaging. However, these materials need improvements in their physical, chemical, and mechanical properties to be used in packaging. In this work, these films were treated with cold plasma to evaluate the effects of treatment conditions on several physical, chemical, and mechanical properties. The dielectric barrier discharge plasma technology was applied with varying treatment times (0 to 20 min) and excitation frequencies (50 to 900 Hz) at 20 kV. The optimal excitation frequency for starch films (50 Hz) was different from the optimal frequency for gelatin and bacterial cellulose films (900 Hz), indicating a high dependency on the treatment in this variable that is often neglected. Plasma treatment improved the hydrophobicity, surface morphology, water resistance, and mechanical properties of all three films, with the advantage of not recurring to chemical or biological additives.

Impacts of cold plasma treatment on physicochemical, functional, bioactive, textural, and sensory attributes of food: A comprehensive review

Cold plasma processing is a technique that uses electricity and reactive carrier gases, such as oxygen, nitrogen, or helium, to inactivate enzymes, destroy microorganisms, preserve food, and maintain quality without employing chemical antimicrobial agents.The review collates the latest information on the interaction mechanism and impact of non-thermal plasma, as an emerging processing technology, on selected physical properties, low-molecular-weight functional components, and bioactive properties of food. Significant changes observed in the physicochemical and functional properties. For example, changes in pH, total soluble solids, water and oil absorption capacities, sensory properties such as color, aroma, and texture, bioactive components (e.g., polyphenols, flavonoids, and antioxidants), and food enzymes, antinutrients, and allergens were elaborated in the present manuscript. It was highlighted that the plasma reactive species result in both constructive and antagonistic outcomes on specific food components, and the associated mechanism was different in each case. However, the design's versatility, characteristic non-thermal nature, better economic standards, and safer environmental factors offer matchless benefits for cold plasma over conventional processing methods. Even so, a thorough insight on the impact of cold plasma on functional and bioactive food constituents is still a subject of imminent research and is imperative for its broad recognition as a modern non-conventional processing technique.

In vivo Assessment of Cold Atmospheric Pressure Plasma Technology on the Bioactivity of Spirulina

The present study challenges the in vivo assessment of cold atmospheric pressure plasma (CAPP) technology on the bioactive activity (antioxidant/antiaging and antimicrobial potential) of Spirulina powder, using Caenorhabditis elegans as an animal model. Surface microdischarge cold atmospheric pressure plasma (SMD-CAPP) treatment was 3.3 W discharge power for 7 min. C. elegans lifespan and egg laying were used as indicators of antioxidant/antiaging potential of Spirulina (1 mg/mL), when grown with Spirulina CP-treated [E_SCP] and untreated [E_S], compared with a control [E_0] (non-supplemented with Spirulina). According to our results, under both Spirulina supplemented media [E_SCP and E_S] and for the first 17 days, nematodes experienced an increase in lifespan but without significant differences (p > 0.05) between control and Spirulina CP-treated. Regarding the in vivo assay of the antimicrobial potential of Spirulina against Salmonella enterica serovar Typhimurium (infected worms), no significant differences (p > 0.05) were found between the three exposure scenarios (control [S_0]; Spirulina supplemented media [S_S]; CP-treated Spirulina supplemented media [S_SCP]). According to present results, CAPP-treatment do not influence negatively the lifespan of C. elegans but a reduction in the Spirulina antiaging potential was found. No in vivo modifications in antimicrobial activity seem to be linked to CAPP-processed Spirulina.

Feasibility of atmospheric cold plasma for the elimination of food hazards: Recent advances and future trends

In recent decades, food safety has emerged as a worldwide public health issue with economic and political implications. Pesticide residues, mycotoxins, allergens, and antinutritional factors are the primary concerns associated with food products due to their potential adverse health effects. Although various conventional processing methods (such as washing, peeling, and cooking) have been used to reduce or eliminate these hazards from agricultural food materials, the results obtained are not quite satisfactory. Recently, atmospheric cold plasma (ACP), an emerging low -temperature and green processing technology, has shown great potential for mitigating food hazards. However, detailed descriptions of the effects of ACP treatment on food hazards are still not available. Thus, the current review aims to highlight recent studies on the efficacy and application of ACP in the reduction or elimination of pesticide residues, mycotoxins, allergens, and antinutritional factors in various food products. The possible working mechanisms of ACP and its effect on food quality, and the toxicity of degradation products are emphatically discussed. In addition, multiple factors affecting the efficacy of ACP are summarized in detail. At the same time, the major technical challenges for practical application and future development prospects of this emerging technology are also highlighted.

Impact of cold plasma processing on major peanut allergens

Cold plasma is emerging as a novel food processing technology, with demonstrated efficacies for microbial inactivation and residual chemical dissipation of food products. Given the technology's multimodal action it has the potential to reduce allergens in foods, however data on the efficacy and mechanisms of action are sparse. This study investigates the efficacy of cold plasma on major peanut allergens (Ara h 1 and Ara h 2). For this purpose, dry, whole peanut (WP) and defatted peanut flour (DPF) were subjected to an atmospheric air discharge using a pin to plate cold plasma reactor for different treatment durations. With increases in plasma exposure, SDS-PAGE analysis revealed reduced protein solubility of the major peanut allergens. Alterations in allergenicity and structure of Ara h 1 and Ara h 2 were examined using ELISA and circular dichroism (CD) spectroscopy. Competitive ELISA with proteins purified from plasma treated WP or DPF revealed reduced antigenicity for both Ara h 1 and Ara h 2. The highest reduction in antigenicity was 65% for Ara h 1 and 66% Ara h 2 when purified from DPF. Results from CD spectroscopy analysis of purified proteins strongly suggests the reduction in antigenicity is due to modifications in the secondary structure of the allergens induced by plasma reactive species. Cold plasma is effective at reducing peanut protein solubility and causes changes in allergen structure leading to reduced antigenicity.

Volatile compounds associated to the loss of astringency in 'Rama Forte' persimmon fruit

The volatile profile of 'Rama Forte' persimmon fruit treated with high concentration of CO₂ or ethanol, as well as the association of specific volatile organic compounds (VOC) to the loss of astringency given by sensory and chemical evaluation were investigated in our study. Fruit were harvested at the maturity stage showing crisp texture and commercial color, and exposed to different astringency removal treatments: 70% CO₂ for 18 h or 1.70 mL kg^-1 ethanol for 6 h. Fruit were daily assessed for VOC, astringency, and soluble tannins content throughout eight days at room temperature. The HS-SPME/GC-MS analysis allowed to tentatively identify 31 volatile compounds and two fatty acids. A clear separation of the persimmon fruit from the beginning to the end of the post-treatment period was showed by PCA results, mainly from the fifth day for CO₂-treated and the seventh day for ethanol-treated persimmon. The loadings from CO₂ treatment highlighted the increase in the concentrations of a great number of compounds with the progression of the days. The compounds 2,4-di-tert-butylphenol and 1-pentadecanal were tentatively identified on fruit from both treatments after the longest periods and were absent on astringent non-treated fruit. These compounds are reported for the first time on persimmon fruit. Astringency tending to absent was noticed from the fifth and the seventh day after the fruit exposition to CO₂ and ethanol vapor, respectively, when flesh soluble tannins concentrations close to 0.1% FW were found. Our study indicates a strong relationship between the astringency removal and the compounds 2,4-di-tert-butylphenol and 1-pentadecanal, supporting them as potential marker compounds for artificial deastringency in 'Rama Forte' persimmon fruit.