Effect of low temperature plasma on the functional properties of basmati rice flour

Impact of genotypic variation and cultivation conditions on the techno-functional characteristics and chemical composition of 25 new Canadian quinoa cultivars

The utilization of quinoa in food production requires comprehensive information on its processing characteristics. Twenty-five new quinoa cultivars developed by the Northern Quinoa Breeding Program, grown in three Canadian locations over two seasons, were characterized for their proximate composition, pasting properties, thermal properties, water absorption index, water solubility index, foaming capacity, foaming stability, oil holding capacity, and emulsion activity crucial for potential food applications. Results showed significant variations in the proximate composition among the cultivars, which was also influenced by the growing location and harvest year. Significant differences (p < 0.05) were also observed in the pasting properties, thermal stability, hydration properties, foaming properties, oil holding capacity, and emulsion activity. The hierarchical cluster and principal component analyses were associated with five distinct clusters of quinoa cultivars, each with unique techno-functional attributes, suggesting their potential for different food applications. These findings emphasize the need for further research to explore the performance of quinoa flours in specific food products and their impact on end-product quality.

Physicochemical characterization and sensory enhancement of cold plasma treated black whole wheat flour

This study examined the effects of cold plasma (CP) treatment on the physicochemical properties and sensory quality of black whole wheat flour (BWWF). Various factors including nutrient composition, color, amino acids, aroma, particle size, microstructure, antioxidant activity, and water migration were analyzed before and after CP treatment. The findings revealed that CP treatment had a minimal impact on the baseline nutrient composition of BWWF, but significantly improved its free amino acid profile, enhancing its nutritional value. The treated BWWF had an improved surface color, appeared brighter and yellower, and gave off a pleasant mellow aroma, while removing unpleasant flavor. The total phenolic content of BWWF increased while the flavonoid and anthocyanin content decreased after the treatment. CP-treated BWWF underwent aggregation cross-linking in the microstructure, and the content of bound water decreased, but the stability increased. In conclusion, CP treatment had great potential to improve the physicochemical properties and sensory quality of BWWF.

Effects of emerging food pretreatment and drying techniques on protein structures, functional and nutritional properties: An updated review

Protein is one of the most important components of food which significantly contributes to the structure, functionality, and sensory properties which may affect consumer acceptability of processed products. Conventional thermal processing affects protein structure and induce undesirable degradation of food quality. This review provides an overview of emerging pretreatment and drying technologies (plasma treatment, ultrasound treatment, electrohydrodynamic, radio frequency, microwave, and superheated steam drying) in food processing by assessing protein structural changes to enhance functional and nutritional properties. In addition, mechanisms and principles of these modern technologies are described while challenges and opportunities for the development of these techniques in the drying process are also critically analyzed. Plasma discharges can lead to oxidative reactions and cross-linking of proteins that can change the structure of proteins. Microwave heating contributes to the occurrence of isopeptide or disulfide bonds which promotes α-helix and β-turn formation. These emerging technologies can be adopted to improve protein surface by exposing more hydrophobic groups which restrict water interaction. It is expected that these innovative processing technologies should become a preferred choice in the food industry for better food quality. Moreover, there are some limitations for industrial scale application of these emerging technologies that need to be addressed.

Cold plasma: Unveiling its impact on hydration, rheology, nutritional, and anti-nutritional properties in food materials - An overview

Non-thermal technologies, primarily employed for microbial inactivation and quality preservation in foods, have seen a surge in interest, with non-thermal plasma garnering particular attention. Cold plasma exhibits promising outcomes, including enhanced germination, improved functional and rheological properties, and microorganism destruction. This has sparked increased exploration across various domains, notably in hydration and rheological properties for creating new products. This review underscores the manifold benefits of applying cold plasma to diverse food materials, such as cereal and millet flours, and gums. Notable improvements encompass enhanced functionality, modified color parameters, altered rheological properties, and reduced anti-nutritional factors. The review delves into mechanisms like starch granule fragmentation, elucidating how these processes enhance the physical and structural properties of food materials. While promising for high-quality food development, overcoming challenges in scaling up production and addressing legal issues is essential for the technology's commercialization.

Understanding the atmospheric cold plasma-induced modification of finger millet (Eleusine coracana) starch and its related mechanisms

This research was conducted to evaluate the effects of cold plasma (CP) on finger millet starch (FMS). FMS was exposed to partially ionized gas at varying voltages (170, 200, and 230 Volt) for varied time (10, 20, and 30 mins). The impact of treatment was studied using physico-chemical, and functional properties, and the mechanisms of starch modification occurring were stated. A significant reduction in the degree of polymerization was noticed based on parameters like reducing sugar, amylose content, solubility, and molecular weight. However, in certain voltage and time combinations, crosslinking was also confirmed by analysis such as XRD, FTIR, DSC, etc. The properties of starch were altered such as remarkable increase in water solubility by 6.7 times for highest voltage and longest time (230 V/30 min) was registered. NMR data suggested valuable findings- oxidation of OH group at C6 position of starch led to formation of carbonyl group followed by carboxyl group. NMR also showed a decrease in OH protons confirming crosslinking and hence all these analyses helped to conclude findings about the quality changes using CP. It was observed that the highest voltage and considerably longer exposure time of 20 and 30 min induced significant changes in the FMS.

The Effect of Atmospheric Dielectric Barrier Discharge Cold Plasma Treatment on the Nutritional and Physicochemical Characteristics of Various Legumes

High activity of lipoxygenase (LOX) has been identified as a primary cause of oxidative rancidity in legumes. In this study, the application of dielectric barrier discharge atmospheric cold plasma (DBD-ACP) (5 W, 10 min) resulted in an obvious decrease in LOX activity in mung bean (MB), kidney bean (KB), and adzuki bean (AB) flours by 36.96%, 32.49%, and 28.57%, respectively. Moreover, DBD-ACP induced significant increases (p < 0.05) in content of soluble dietary fiber, saturated fatty acids, and methionine. The starch digestibility of legumes was changed, evidenced by increased (p < 0.05) slowly digestible starch and rapidly digestible starch, while resistant starch decreased. Furthermore, DBD-ACP treatment significantly affected (p < 0.05) the hydration and thermal characteristics of legume flours, evidenced by the increased water absorption index (WAI) and gelatinization temperature, and the decreased swelling power (SP) and gelatinization enthalpy (ΔH). Microscopic observations confirmed that DBD-ACP treatment caused particle aggregation.

Effects of pin-to-plate atmospheric cold plasma for modification of pearl millet (Pennisetum glaucum) starch

The present study was done to analyze the effect of atmospheric pressure non-thermal pin-to-plate plasma at a range of different voltages (170, 200, and 230V) at different time intervals (10, 20, and 30 mins) on under-utilized pearl millet starch. The untreated and treated starches were analyzed for amylose content, pH, carbonyl, and carboxyl group, reducing sugar, turbidity, water, and oil binding property, pasting property, DSC, FTIR, XRD, and molecular weight. As cold plasma contains highly reactive species and free radicals, it is expected to cause noticeable modifications in the attributes of treated starch. There has been a significant reduction (p < 0.05) in turbidity value by 38.97% and pH value of starch from 6.49 to 4.05. Plasma-treated samples produced clearer pastes with higher stability over storage time. Cold plasma treatment also led to an increase in the ζ potential. However, there has been no significant change in the water activity and oil-binding capacity of the starch. Reducing sugar content, average molecular weight, degree of polymerization, pasting property, XRD, and FTIR data confirmed that cross-linking takes place in samples treated at lower voltages and lesser time followed by depolymerization occurring in harshly treated plasma samples. The study thus points out the possible use of cold plasma for starch modification to produce starches with altered properties.

Atmospheric cold plasma induced nutritional & anti-nutritional, molecular modifications and in-vitro protein digestibility of guar seed (Cyamopsis tetragonoloba L.) flour

The present study was carried out to investigate the effect of atmospheric cold plasma treatment on the nutritional, anti-nutritional, functional, morphological, and digestibility of guar seed (Cyamopsis tetragonoloba L.) flour. Here, guar seed flour was kept inside the plasma reactor for 5 to 20 min at different power levels (10 & 20 kV). The cold plasma treatment (CPT) significantly (p < 0.05) reduced the carbohydrate (46.87 - 36.81 %), protein (27.15 - 25.88 %), and increased the WAC (1.89 - 2.91 g/g), OAC (1.18 - 2.17 g/g), FC (113 - 186.17 %), and pasting properties of guar seed flour. High-intensity plasma-treated samples (20 kV-20 min) contained lesser tannin, phytic acid, and saponin with reduced the nutritional value. The FTIR spectrum suggested that functional group formation or destruction might have occurred in the plasma-treated samples. Additionally, the crystallinity is reduced with increasing applied voltage or duration. The SEM analysis reveals that CPT resulted in the formation of rough surfaces with highly porous structures. On the other hand, CPT significantly reduced the trypsin inhibitor activity and had a minor impact on in-vitro protein digestibility except for the 20 kV-20 min treated sample. In PCA analysis, 10 kV-15 min treated samples exhibited better nutritional value, functional, and pasting properties with maximum impact of anti-nutritional factors. From the results, it can be concluded that treatment duration rather than the applied voltage plays a significant role in preserving the nutritional content.

Product development and X-Ray microtomography of a traditional white pan bread from plasma functionalized flour

Cold plasma (CP) technology has emerged as a novel non-thermal technology with the potential to improve food quality or impart functionality to ingredients. Our previous studies on wheat flour demonstrated how the structure and functionality of wheat flour might be modified using CP to provide an alternative to chemical additives (Chaple et al., 2020). However, understanding of the further effects of plasma functionalized ingredients in existing or new product formulation is limited. This study investigated the effects of CP treatment of wheat flour on traditional white pan bread development. The bread was formulated using plasma functionalized flour (PFF), and critical product characteristic responses were analyzed. Plasma treatment of flour positively affected the bread's expansion ratio, crust color, and water activity. Farinograph analysis suggests improvement in water absorption capacity, dough development time, and dough stability. X-Ray Microtomography (XRMT) analysis was conducted to understand how plasma functionalising the flour impacted the microstructure of bread. The 3D scans suggested no macro-change in the bread matrix compared to control; however, the porosity decreased in line with the increasing plasma treatment duration of the flour. The texture profile analysis showed an improvement in the gluten network developed in the dough developed from PFF. Sensory analysis results showed overall acceptance for bread formulated with PFF compared with a commercial sample. Overall, CP treatment of the flour improved the functionality in relation to dough and bread preparation and can thus provide an alternative to chemical additives in bread making. The CP processes may be modulated to deliver tailored effects for bread product development.

Effect of atmospheric nonthermal plasma on physicochemical, morphology and functional properties of sunn pest (Eurygaster integriceps)-damaged wheat flour

To improve the quality of sunn pests (Eurygaster integriceps)-damaged wheat flour, the effects of nonthermal plasma on physicochemical, rheological, functional, and microstructural properties were investigated. Gas type (air and oxygen), voltage (22 and 25 volts), and time (0, 2, 4, 6, 8, and 10 min) were the variables of the experiments conducted using a completely randomized design with three replications. The results show that with increasing voltage and time of plasma treatment, the pH decreased significantly (p ≥ .05), and brightness parameter, yellow-blue parameter, water-solubility, water absorption, oil absorption, and swelling power increased significantly (p ≥ .05). The duration of plasma treatment, voltage, and change in input gas from air to oxygen did not significantly change the gluten index, particle size, and negative electric charge of flour particles, and the amount of zeta potential of samples. Differential calorimetric analysis showed the first and second peaks of the thermogram in the range 55-99°C and also 114-99°C. Infrared spectroscopy (FT-IR) showed hydroxyl group, CH bonds, C=O bonds, as well as the presence of types I and II amide bonds in the structure. Microstructural results indicated that plasma treatment reduced the particle size and increased particle sorting. By Increasing voltage and the duration of plasma treatment, peak viscosity, final viscosity, breakdown viscosity, pasting time and temperature significantly increased and setback viscosity decreased (p ≥ .05), which reduced retrogradation which improved the dough stability during the cooling process.

Cold plasma: a promising technology for improving the rheological characteristics of food

At the beginning of the 21st century, many consumers show interest in purchasing safe, healthy, and nutritious foods. The intent requirement of end-users and many food product manufacturers are trying to feature a new processing technique for the healthy food supply. The non-thermal nature of cold plasma treatment is one of the leading breakthrough technologies for several food processing applications. The beneficial response of cold plasma processing on food quality characteristics is widely accepted as a substitution technique for new food manufacturing practices. This review aims to elaborate and offer crispy innovative ideas on cold plasma application in various food processing channels. It highlights the scientific approaches on the principle of generation and mechanism of cold plasma treatment on rheological properties of foods. It provides an overview of the behavior of cold plasma in terms of viscosity, crystallization, gelatinization, shear stress, and shear rate. Research reports highlighted that the cold plasma treated samples demonstrated a pseudoplastic behavior. The published literatures indicated that the cold plasma is a potential technology for modification of native starch to obtain desirable rheological properties. The adaptability and environmentally friendly nature of non-thermal cold plasma processing provide exclusive advantages compared to the traditional processing technique.

Recent trends and technological development in plasma as an emerging and promising technology for food biosystems

The rising need for wholesome, fresh, safe and “minimally-processed” foods has led to pioneering research activities in the emerging non-thermal technology of food processing. Cold plasma is such an innovative and promising technology that offers several potential applications in the food industry. It uses the highly reactive, energetic and charged gas molecules and species to decontaminate the food and package surfaces and preserve the foods without causing thermal damage to the nutritional and quality attributes of food. Cold plasma technology showed promising results about the inactivation of pathogens in the food industry without affecting the food quality. It is highly effective for surface decontamination of fruits and vegetables, but extensive research is required before its commercial utilization. Recent patents are focused on the applications of cold plasma in food processing and preservation. However, further studies are strongly needed to scale up this technology for future commercialization and understand plasma physics for getting better results and expand the applications and benefits. This review summarizes the emerging trends of cold plasma along with its recent applications in the food industry to extend shelf life and improve the quality of food. It also gives an overview of plasma generation and principles including mechanism of action. Further, the patents based on cold plasma technology have also been highlighted comprehensively for the first time.

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.

Nonthermal physical modification of starch: An overview of recent research into structure and property alterations

To tailor the properties and enhance the applicability of starch, various ways of starch modification have been practiced. Among them, physical modification methods (micronization, nonthermal plasma, high-pressure, ultrasonication, pulsed electric field, and γ-irradiation) are highly potential for starch modification considering its safety, environmentally friendliness, and cost-effectiveness, without generating chemical wastes. Thus, this article provides an overview of the recent advances in nonthermal physical modification of starch and summarizes the resulting changes in the multi-level structures and physicochemical properties. While the effect of these techniques highly depends on starch type and treatment condition, they generally lead to the destruction of starch granules, the degradation of molecules, decreases in crystallinity, gelatinization temperatures, and viscosity, increases in solubility and swelling power, and an increase or decrease in digestibility, to different extents. The advantages and shortcomings of these techniques in starch processing are compared, and the knowledge gap in this area is commented on.

Modifying Effects of Physical Processes on Starch and Dietary Fiber Content of Foodstuffs

Carbohydrates are one of the most important nutrients in human consumption. The digestible part of carbohydrates has a significant role in maintaining the energy status of the body and the non-digestible parts like dietary fibers have specific nutritional functions. One of the key issues of food processing is how to influence the technological and nutritional properties of carbohydrates to meet modern dietary requirements more effectively, considering particularly the trends in the behavior of people and food-related health issues. Physical processing methods have several advantages compared to the chemical methods, where chemical reagents, such as acids or enzymes, are used for the modification of components. Furthermore, in most cases, these is no need to apply them supplementarily in the technology, only a moderate modification of current technology can result in significant changes in dietary properties. This review summarizes the novel results about the nutritional and technological effects of physical food processing influencing the starch and dietary fiber content of plant-derived foodstuffs.

Effect of high voltage atmospheric cold plasma on extraction of fenugreek galactomannan and its physicochemical properties

Fenugreek is a good source of galactomannan, however, conventional methods for its extraction are generally time-consuming and have relatively low recovery rates. In this study, we applied high voltage atmospheric cold plasma (HVACP) as a pretreatment and investigated its effects on galactomannan extraction from dry fenugreek seeds and soaked seeds in NaCl solution, as well as its physicochemical properties. Results showed that HVACP treatment with air at 80 kV for 30 min caused apparent structural disruption on fenugreek seed surface and decreased the pH of extracting solution, resulting in increased galactomannan extraction yields, by 122% from soaked seeds and 67% from dry seeds. Galactomannan treated with HVACP had higher water-binding capacity, swelling index and viscosity, as well as lower melting enthalpy. HVACP treatment also altered the surface morphology of galactomannan due to plasma etching, but no significant changes in its molecular and crystalline structures were observed. The findings of this study prove that HVACP can be a green approach, in terms of reduced chemical use, to effectively enhance the extraction efficiency of fenugreek galactomannan and modify its functional properties, hence facilitate more diverse applications in both food and polymer industries.

Modification of the physicochemical and structural characteristics of zein suspension by dielectric barrier discharge cold plasma treatment

Owing to the strong hydrophobicity of zein, improved solubility is required to enhance the recovery of bioactive peptides. Using a zein suspension prepared by the antisolvent precipitation method, the impact of varying the voltage during dielectric barrier discharge (DBD) treatment on the physicochemical and conformational properties of zein in water was investigated. Analysis of the particle size, specific surface area, and free sulfhydryl content indicated that the protein solubility was maximized by treatment at 70 V for 70 s. DBD treatment destroyed covalent bonds and introduced some hydrophilic groups onto the zein surface, thus enhancing the contact area with water molecules and leading to a more uniform dispersion. A decrease in the hydrodynamic radius of zein micelles indicated that intermolecular interactions were disrupted, thus improving dispersion stability. A more hydrophilic microenvironment was formed owing to the reduction in hydrophobic interactions. Additionally, evaluation of the secondary structure demonstrated that DBD treatment broke hydrogen bonds, resulting in a loose conformation with more exposed sites of action for water. These results are expected to facilitate the development of technologies for improving utilization of zein. PRACTICAL APPLICATION: Strong hydrophobicity limits the application of zein in the food industry. The study indicated that DBD treatment could promote loose structure, and improve dispersion stability and hydrophilicity of zein suspension prepared by antisolvent precipitation method. This work revealed the potential of cold plasma treatment for modifying zein and other insoluble proteins, which would expand their scope of application.

Influence of Plasma Treatment on the Polyphenols of Food Products—A Review

The consumption of bioactive compounds, especially phenolic compounds, has been associated with health benefits such as improving the health status and reducing the risk of developing certain diseases such as cancer, cardiovascular diseases, and neurodegenerative disorders. However, the preservation of natural bioactive compounds in food products is a major challenge for the food industry. Due to the major impact of conventional thermal processing, nonthermal technologies such as cold plasma have been proposed as one of the most promising solutions for the food industry. This review will cover the current knowledge about the effects of cold plasma in polyphenols found in food products. The increasing number of studies in the last years supports the continuous search for specific treatment conditions for each type of food and the central role of plasma treatments as a food-processing technology.

Efficacy of cold plasma in producing Salmonella-free duck eggs: effects on physical characteristics, lipid oxidation, and fatty acid profile

Concerns related to foodborne pathogens necessitate the decontamination of avian eggs. Conventional decontamination methods, such as egg washing, usually use health-threatening chemicals (e.g. chlorine). Hence, innovative chemical-free decontamination approaches are interesting for the food industry, especially to decontaminate commonly Salmonella infected products such as duck eggs. The present study is the first attempt to evaluate the effectiveness of cold plasma against Salmonella enterica inoculated on the surface of duck eggshell. In this regard, Salmonella-contaminated duck eggs were treated by arc plasma for 10, 20, 30, and 40 s. The bacteria count, eggshell strength, color, pH, Haugh unit, acid value (AV), thiobarbituric acid reactive substances (TBARS), and fatty acid profile of the plasma-treated samples were then compared with those of untreated sample. According to the results, all the plasma treatments significantly decreased the Salmonella population and longer treatment times enhanced the bactericidal effects of plasma. A maximum bacterial reduction of 4.1 log cycle was observed when plasma was applied for 40 s. Furthermore, plasma treatments did not deteriorate the quality parameters of eggs such as eggshell strength, eggshell color, yolk color, Haugh unit, AV, and TBARS. These findings introduced arc plasma as an emerging tool for improving the safety of duck eggs with good potential for industrial application.

Modification of Konjac Glucomannan by Reduced-Pressure Radio-Frequency Air Plasma

The potential of reduced-pressure radio-frequency air plasma (RFAP) in the modification of konjac glucomannan (KGM) was investigated. KGM film was exposed to 100 W RFAP for 50 s, 100 s, 150 s, 200 s, and 250 s, ground, and then subjected to various characterizations. Fourier Transform Infrared Spectroscopy (FTIR) revealed that RFAP treatment increased the content of –OH groups in KGM, with the lowest and highest rise occurring at the exposure durations 150 s and 250 s, respectively. RFAP radiation decreased the solubility of KGM at certain exposure durations, but slightly increased its thermal stability. Exposure to RFAP for 150 s and 250 s increased the hardness of the resultant KGM gel, but decreased the viscosity and elasticity of the KGM solution in a duration-dependent manner. Scanning Electron Microscope (SEM) observation revealed that RFAP treatment led to rougher surfaces and XRD (X-Ray Diffraction) analysis indicated the destroyed crystallinity of KGM. Hence, RFAP has potential application in the modification of KGM.