Review about?cold atmospheric plasma-induced protein modification, to improve protein quality

With the constant increase in protein demand globally, it is expedient to develop a strategy to effectively utilize protein, particularly those extracted from plant origin, which has been associated with low digestibility, poor techno-functional properties, and inherent allergenicity. Several thermal modification approaches have been developed to overcome these limitations and showed excellent results. Nevertheless, the excessive unfolding of the protein, aggregation of unfolded proteins, and irregular protein crosslinking have limited its application. Additionally, the increased consumer demand for natural products with no chemical additives has created a bottleneck for chemical-induced protein modification. Therefore, researchers are now directed toward other nonthermal technologies, including high-voltage cold plasma, ultrasound, high-pressure protein, etc., for protein modification. The techno-functional properties, allergenicity, and protein digestibility are greatly influenced by the applied treatment and its process parameters. Nevertheless, the application of these technologies, particularly high-voltage cold plasma, is still in its primary stage. Furthermore, the protein modification mechanism induced by high-voltage cold plasma has not been fully explained. Thus, this review meets the necessity to assemble the recent information on the process parameters and conditions for modifying proteins by high-voltage cold plasma and its impact on protein techno-functional properties, digestibility, and allergenicity. 1 IntroductionUndoubtfully the protein demand globally is expected to increase with the increasing human population (Henchion et al., 2017). Factors including socio-economic changes and the recognition of the role of protein in healthy aging and diet play an important role in the increasing protein demand (Henchion et al., 2017; Hewage et al., 2022; Popkin et al., 2012). Although the current sources of protein include both animal- and plant-based proteins, animal-based proteins, such as meat, poultry, dairy foods, fish, and eggs, are considered nutritionally complete proteins, whereas plant-based proteins extracted from fruits, vegetables, grains, nuts, and seeds, lack one or more essential amino acids. Therefore, sourcing other sustainable protein sources or adopting methods and technologies for improving protein ingredients to meet future demands is imperative. In food, protein is an essential biopolymer whose diverse functional properties influence its behavior in food formulation during processing, storage, cooking, and consumption (Kinsella, 1979), thus contributing to the wide protein application in the food industry (Akharume et al., 2021). The versatility of proteins is embedded in their amphipathic nature enabling them to act as a surface-active agent for interaction with other food components and air (Akharume et al., 2021; O'Sullivan et al., 2016; Popkin et al., 2012). Regardless of the protein source, solubility, viscosity, foaming ability, emulsification capacity, gelation, water-holding capacity (WHC), and oil-holding capacity (OHC) are some of the most critical protein techno-functional properties of utmost importance in the food industry (Bandara et al., 2018; Hadna?ev et al., 2017; Nadeeshani et al., 2022). Additionally, the digestibility and bioaccessibility of dietary protein are other factors influencing protein application in the food industry. These factors depend on extrinsic and intrinsic parameters, including protein extraction methods, protein source, amino acid composition and sequences, molecular weight, purity, and so on. Hence, the modification of proteins has been an approach to meet the global demand for protein and as well revolutionizes the application of protein in the food industry via the improved digestibility and techno-functional properties as well as reduced inherent allergenicity The modification of protein has become an essential aspect of protein chemistry for improving protein quality, both nutritional and techno-functional properties. These modifications can be thermal or nonthermal (Nasrabadi et al.,, 2021). The loss of the native conformation of the protein associated with the rupture of weak intramolecular forces in protein, including nonpolar interaction, various kinds of electrostatic interaction, and disulfide bonds mediated by the kinetic energy provided to the polypeptides when subjected to heat treatment is the major mechanism of thermal modification of proteins (Davis & Williams, 1998; Yu et al., 2017). However, the excessive unfolding of the protein, aggregation of unfolded proteins, and irregular protein crosslinking, which leads to loss of techno-functional properties, are drawbacks of this protein modification method. Therefore, the industry and academia have developed nonthermal modification methods to enhance protein quality and functionality. Chemical modification of protein is the most common nonthermal modification method with promising results. This modification leverages the numerous reactive side chains contained in the protein's primary structure (Lodish et al., 2000), which are available for interaction. Some common chemical protein modification includes acylation, methylation, phosphorylation, sulfation, farnesylation, ubiquitination, glycosylation, and so on (Akharume et al., 2021; Boutureira & Bernardes, 2015). However, the consumer demand for natural products with no chemical additives or modifications and the popularization of clean-label products has created a challenge for the future of chemical protein modification. Additionally, environmental pollution, difficulty in recycling, and high production costs are the other potential drawbacks of this method. Therefore, developing protein modification methods and technologies in the green chemistry space is urgently required. Recently, attention has been shifted toward applying novel nonthermal processing techniques for modifying food proteins. For instance, high-voltage cold atmospheric plasma (HV-CAP) was used to modify fish myofibrillar protein (Olatunde et al., 2021b). Similarly, proteome- and flavor-related proteins of unsmoked bacon were modified with ultrasound (Zhang et al., 2022a). Peas, rice, and gluten were modified with moderate-intensity pulsed electric fields (PEFs; Melchior et al., 2020). Furthermore, Hall and Moraru (2022) demonstrated the efficacy of high-pressure processing in modifying pea protein's structure and in vitro digestibility. These green technologies induce changes in secondary and tertiary structures of protein, leading to protein aggregation and crosslinking. Depending on the applied treatment and its process parameters, the techno-functional properties of the protein, especially hydrophobicity, solubility, emulsion, and foaming properties, have been greatly influenced. Although these nonthermal technologies have been very effective in protein modification, the application of HV-CAP is still in its infancy. Furthermore, there is minimal information on the application of HV-CAP for protein modification, mainly plant-based protein, for which demand has been on the horizon. Compared to other nonthermal processing technologies, HV-CAP is a novel technology in food processing that falls in the green processing, environmental friendliness, low cost of installation and implementation, and sustainability category. This technology could be an innovative nonthermal approach for revolutionizing the application of protein in the food industry via improved digestibility and techno-functional properties, as well as reduced inherent allergenicity. Furthermore, this modification and improving protein properties are expected to help develop ingredients from underutilized sources. Thus, this review gathers the most recent information on the process parameters for protein modification by HV-CAP and its impact on protein quality, techno-functional properties, digestibility, and allergenicity. All the contents2 Technology and mechanisms of HV-CAP in protein modificationsHV-CAP technologyHV-CAP systemsMechanism of HV-CAP in protein modifications 3 HV-CAP for protein modificationImpact of HV-CAP on protein allergenicity reductionEffect of HV-CAP in improving techno-functional properties of proteins3.2.1 Protein solubility3.2.2 Rheological properties, water- and oil-holding capacity, and viscosity3.2.3 Interfacial properties (emulsion and foaming properties)3.2.4 Gelation3.2.5 Film formation abilityThermal stabilityEffect of HV-CAP on improving protein digestibility and nutritional qualities4 Conclusion and future outlook of HV-CAP in protein modification The figure is picture 2 of the original paper, Mechanism of protein oxidation induced by reactive species produced by high-voltage cold atmospheric plasma (HV-CAP) SourceCold atmospheric plasma-induced protein modification: Novel nonthermal processing technology to improve protein quality, functionality, and allergenicity reductionOladipupo Odunayo Olatunde, Anuruddika Hewage, Thilini Dissanayake, Rotimi E. Aluko, Asli Can Karaca, Nan Shang & Nandika BandaraComprehensive Review in Food Science and Food SafettyFirst published: 30 March 2023https://ift.onlinelibrary.wiley.com/doi/10.1111/1541-4337.13144?af=R&utm_medium=email&utm_source=rasa_io&utm_campaign=newsletterhttps://doi.org/10.1111/1541-4337.13144