The use of atmospheric pressure plasma-treated water as a source of nitrite for emulsion-type sausage

Reduction of N-nitrosamine in cured ham using atmospheric cold plasma-treated cauliflower powder

The effects of cauliflower treated with atmospheric cold plasma (ACP), as a natural nitrite source, on the curing of ground ham and nitrosamine formation were investigated. Ground ham was prepared using sodium nitrite and ACP-treated cauliflower powder (PTCP) to achieve initial nitrite concentrations of 60 and 100 mg/kg, respectively. ACP treatment generated nitrite in cauliflower but significantly reduced the antioxidant activity (P < 0.05). As a nitrite source, PTCP had similar effects as sodium nitrite in the development of cured color in ground ham, with a comparable residual nitrite content (P ≥ 0.05). Three nitrosamines, N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), and N-nitrosopyrrolidine (NPYR), were detected in ground ham. NPYR formation was significantly lower in ground ham treated with PTCP at an initial nitrite concentration of 100 mg/kg (P < 0.05). Therefore, the use of a natural nitrite source manufactured through ACP treatment can prospectively achieve suitable curing efficiency while simultaneously suppressing nitrosamine formation.

Inhibitory effects of cold plasma-activated water on the generation of advanced glycation end products and methylimidazoles in cookies and mechanistic evaluation using electron paramagnetic resonance

The inhibitory effects of cold plasma-activated water (PAW) on the formation of AGEs and methylimidazoles in cookies was examined. The results showed that different PAW (parameters: 50 W-50 s, 50 W-100 s, 50 W-150 s, 100 W-50 s, 100 W-100 s, and 100 W-150 s) reduced the contents of AGEs and methylimidazoles, in which the maximum inhibition rates were 47.38% and 40.17% for free and bound AGEs and 44.16% and 40.31% for free and bound methylimidazoles, respectively. Moreover, the mechanisms associated with the elimination of carbonyl intermediates and free radicals was determined by electron paramagnetic resonance (EPR) and high performance liquid chromatography-ultraviolet/visible absorption detector (HPLC-UV/Vis). The results showed the quenching of total free radicals, alkyl free radicals, and HO· by PAW, leading to the suppression of glyoxal and methylglyoxal intermediates. These findings support PAW as a promising agent to enhance the safety of cookies.

Simultaneous mitigation of heterocyclic aromatic amines and advanced glycation end products in roasted beef patties by plasma-activated water: Effects and mechanisms

Heterocyclic aromatic amines (HAAs) and advanced glycation end products (AGEs) are hazardous substances produced when food is heated. In this study, the ability of plasma-activated water (PAW) to simultaneously mitigate production of HAAs and AGEs in roasted beef patties was investigated. Assays of free radicals, lipid peroxidation, and active carbonyls were used to analyze the mechanisms. PAW treatment decreased the contents of free HAAs, free AGEs, bound HAAs, and bound AGEs to 12.65 ng/g, 0.10 μg/g, 297.74 ng/g, and 4.32 μg/g, with the inhibition rates of 23.88%, 23.08%, 11.02%, and 8.47%, respectively. PAW treatment decreased HAAs and AGEs and mitigated their increase during storage. The decrease of HAAs and AGEs in PAW-treated samples was correlated with the enhancement of antioxidant capacity. The increase of free radical scavenging ability by PAW treatment led to the decrease of lipid peroxidation and the decrease of active carbonyls, HAAs, and AGEs in meat products.

Using Celery Powder in a Semi-Dry Fermented Sausage 'Heat-Treated Sucuk': Nitrosamine Formation, Lipid Oxidation, and Volatile Compounds

This study investigated the effect of using celery powder (CP) as source of pre-converted nitrite (treatments: A: 150 mg/kg NaNO2, B: 100 mg/kg NaNO2 + CP as 50 mg/kg NaNO2 equivalent, C: 50 mg/kg NaNO2 + CP as 100 mg/kg NaNO2 equivalent, D: CP as 150 mg/kg NaNO2 equivalent) on the physicochemical and microbiological properties in heat-treated sucuk (HTS), a kind of semi-dry fermented sausage. The influence of cooking time (CT) on the nitrosamine formation in HTS with and without CP was also determined. The results indicated that the use of CP increased the pH value and decreased the aw value. Micrococcus/Staphylococcus and residual nitrite were not affected by the use of CP. TBARS value varied from 0.78 to 0.90 mg MDA/kg. CP did not affect the abundance of hexanal in HTS, however, it increased the abundance of camphene. The results of PCA showed that treatments A, B, and C had similar volatile compound profiles. CP did not affect both N-nitrosodimethylamine and N-nitrosodiethylamine, but their levels increased as the CT increased. Increased CT also resulted in increased N-nitrosopiperidine (NPIP) in all treatments, but the cooking for 1 min did not cause a significant increase in treatments A, B, and C. CP leads to a significant increase in NPIP content, especially after 3 and 5 min of cooking in HTS.

Plasma activated water effects on behavior, performance, carcass quality, biochemical changes, and histopathological alterations in quail

BACKGROUND

Plasma-activated water (PAW) is an innovative promising technology which could be applied to improve poultry health. The current study investigated the effects of drinking water supply with PAW on quail behaviour, performance, biochemical parameters, carcass quality, intestinal microbial populations, and internal organs histopathology. A total of 54 twenty-one-day-old Japanese quail chicks were randomly allotted to three treatments provided with PAW at doses 0, 1 ml (PAW-1), and 2 ml (PAW-2) per one litter drinking water. Each treatment contained 6 replicates (3 birds/ cage; one male and two females).

RESULTS

The results clarified that there were no significant (P > 0.05) changes in behaviour, and performance. For the biochemical indicators, the PAW-1 group showed significantly higher serum H2O2, total protein and globulin levels compared with the other groups (P = 0.015, < 0.001, and 0.019; respectively). PAW groups had significantly lower serum creatinine and urea levels than the control (P = 0.003). For the carcass quality, the internal organs relative weight between different treatments was not changed. In contrast, there was a significant increase in the meat colour, taste, and overall acceptance scores in PAW groups compared with the control one (P = 0.013, 0.001, and < 0.001; respectively). For the intestinal microbial population, lactobacilli count was significantly higher in PAW-2 compared with the control group (P = 0.014), while there were no changes in the total bacterial count between different treatment groups. Moreover, mild histological changes were recorded in the intestine, liver, and spleen of PAW groups especially PAW-2 compared with the control one.

CONCLUSIONS

PAW offered benefits, such as reducing creatine and urea levels, improving meat characteristics, and increasing lactobacilli count, all of which are crucial for sustainable quail farming. Therefore, further research is needed.

Enhanced barrier properties in sweet potato starch films via dual modification by octenyl succinylation and heat moisture treatment for use as plant-based sausage casings

This study assesses the impact of dual modification [octenyl succinylation (OSA) and heat-moisture treatment (HMT)] of sweet potato starch (SPS) on the physicochemical, mechanical, and permeability properties of SPS film. The intrinsic limitations of starch films, such as sensitivity to high humidity, inferior mechanical properties, and weak barrier capabilities, have restricted their use in sausage casings. Nonetheless, the dual-modified SPS film (OSA@HMT-SPS film) demonstrated significantly reduced solubility (P < 0.05), moisture content, water vapor permeability (WVP), and O2 permeability compared to the SPS film. Furthermore, its flexibility and elasticity, indicated by its elongation at break, was notably superior. When used as sausage casings, the OSA@HMT-SPS film effectively mitigated lipid oxidation in sausages better than both the SPS film and commercial collagen casings, owing to its low O2 permeability. As a result, the OSA@HMT-SPS casing presents significant promise as a plant-based sausage casing alternative.

A Comprehensive Review of Cured Meat Products in the Irish Market: Opportunities for Reformulation and Processing

Cured meat products constitute one of the meat categories commonly consumed in Ireland and has been part of the Irish cuisine and diet for many years. Ham, gammon, and bacon are some of the products that involve curing as part of the traditional processing methods. Common among these products are high levels of salt and the addition of nitrites. These products undergo processing treatments to create variety, preserve shelf-life, and develop their unique quality and safety characteristics. However, consumers are becoming more conscious of the level of processing involved in these products, and the effects of some components and ingredients might be perceived as unhealthy. Meat product developers have been exploring ways to reduce the amount of ingredients such as salt, saturated fat, and chemical preservatives (e.g., nitrites), which are linked to health concerns. This is a challenging task as these ingredients play an important techno-functional role in the products' quality, safety, and identity. While innovative processing techniques are being introduced and progress has been made in reformulation and packaging technologies, much is still unknown, especially regarding the applicability of many of the proposed interventions to a wide range of meat products and their sustainability at the industrial scale.

Innovative Application of Cold Plasma Technology in Meat and Its Products

The growing demand for sustainable food production and the rising consumer preference for fresh, healthy, and safe food products have been driving the need for innovative methods for processing and preserving food. In the meat industry, this demand has led to the development of new interventions aimed at extending the shelf life of meats and its products while maintaining their quality and nutritional value. Cold plasma has recently emerged as a subject of great interest in the meat industry due to its potential to enhance the microbiological safety of meat and its products. This review discusses the latest research on the possible application of cold plasma in the meat processing industry, considering its effects on various quality attributes and its potential for meat preservation and enhancement. In this regard, many studies have reported substantial antimicrobial efficacy of cold plasma technology in beef, pork, lamb and chicken, and their products with negligible changes in their physicochemical attributes. Further, the application of cold plasma in meat processing has shown promising results as a potential novel curing agent for cured meat products. Understanding the mechanisms of action and the interactions between cold plasma and food ingredients is crucial for further exploring the potential of this technology in the meat industry, ultimately leading to the development of safe and high-quality meat products using cold plasma technology.

Changes in Flavor and Volatile Composition of Meat and Meat Products Observed after Exposure to Atmospheric Pressure Cold Plasma (ACP)

Studies on the atmospheric pressure cold plasma (ACP) exposure of meat and meat products mainly determine microbial inactivation, lipid oxidation, and meat color. Some studies include sensory evaluation, but only a few determine the changes in volatile composition due to ACP treatment. The results of sensory evaluation are inconclusive and range from "improvement" to "off-odor". This could be due to differences in the food matrix, especially in processed foods, or different experimental settings, including inadvertent effects such as sample heating. The few studies analyzing volatile composition report changes in alcohols, esters, aldehydes, and other compounds, but not necessarily changes that are novel for meat and meat products. Most studies do not actually measure the formation of reactive species, although this is needed to determine the exact reactions taking place in the meat during ACP treatment. This is a prerequisite for an adjustment of the plasma conditions to achieve antimicrobial effects without compromising sensory quality. Likewise, such knowledge is necessary to clarify if ACP-exposed meat and products thereof require regulatory approval.

Recent strategies for improving the quality of meat products

Processed meat products play a vital role in our daily dietary intake due to their rich protein content and the inherent convenience they offer. However, they often contain synthetic additives and ingredients that may pose health risks when taken excessively. This review explores strategies to improve meat product quality, focusing on three key approaches: substituting synthetic additives, reducing the ingredients potentially harmful when overconsumed like salt and animal fat, and boosting nutritional value. To replace synthetic additives, natural sources like celery and beet powders, as well as atmospheric cold plasma treatment, have been considered. However, for phosphates, the use of organic alternatives is limited due to the low phosphate content in natural substances. Thus, dietary fiber has been used to replicate phosphate functions by enhancing water retention and emulsion stability in meat products. Reducing the excessive salt and animal fat has garnered attention. Plant polysaccharides interact with water, fat, and proteins, improving gel formation and water retention, and enabling the development of low-salt and low-fat products. Replacing saturated fats with vegetable oils is also an option, but it requires techniques like Pickering emulsion or encapsulation to maintain product quality. These strategies aim to reduce or replace synthetic additives and ingredients that can potentially harm health. Dietary fiber offers numerous health benefits, including gut health improvement, calorie reduction, and blood glucose and lipid level regulation. Natural plant extracts not only enhance oxidative stability but also reduce potential carcinogens as antioxidants. Controlling protein and lipid bioavailability is also considered, especially for specific consumer groups like infants, the elderly, and individuals engaged in physical training with dietary management. Future research should explore the full potential of dietary fiber, encompassing synthetic additive substitution, salt and animal fat reduction, and nutritional enhancement. Additionally, optimal sources and dosages of polysaccharides should be determined, considering their distinct properties in interactions with water, proteins, and fats. This holistic approach holds promise for improving meat product quality with minimal processing.

Novel strategies for controlling nitrite content in prepared dishes: Current status, potential benefits, limitations and future challenges

Sodium nitrite is commonly used as a multifunctional curing ingredient in the processing of prepared dishes, especially meat products, to impart unique color, flavor and to prolong the shelf life of such products. However, the use of sodium nitrite in the meat industry has been controversial due to potential health risks. Finding suitable substitutes for sodium nitrite and controlling nitrite residue have been a major challenge faced by the meat processing industry. This paper summarizes possible factors affecting the variation of nitrite content in the processing of prepared dishes. New strategies for controlling nitrite residues in meat dishes, including natural pre-converted nitrite, plant extracts, irradiation, non-thermal plasma and high hydrostatic pressure (HHP), are discussed in detail. The advantages and limitations of these strategies are also summarized. Raw materials, cooking techniques, packaging methods, and storage conditions all affect the content of nitrite in the prepared dishes. The use of vegetable pre-conversion nitrite and the addition of plant extracts can help reduce nitrite residues in meat products and meet the consumer demand for clean labeled meat products. Atmospheric pressure plasma, as a non-thermal pasteurization and curing process, is a promising meat processing technology. HHP has good bactericidal effect and is suitable for hurdle technology to limit the amount of sodium nitrite added. This review is intended to provide insights for the control of nitrite in the modern production of prepared dishes.

Research Progress and Future Trends of Low Temperature Plasma Application in Food Industry: A Review

Food nutrition, function, sensory quality and safety became major concerns to the food industry. As a novel technology application in food industry, low temperature plasma was commonly used in the sterilization of heat sensitive materials and is now widely used. This review provides a detailed study of the latest advancements and applications of plasma technology in the food industry, especially the sterilization field; influencing factors and the latest research progress in recent years are outlined and upgraded. It explores the parameters that influence its efficiency and effectiveness in the sterilization process. Further research trends include optimizing plasma parameters for different food types, investigating the effects on nutritional quality and sensory attributes, understanding microbial inactivation mechanisms, and developing efficient and scalable plasma-based sterilization systems. Additionally, there is growing interest in assessing the overall quality and safety of processed foods and evaluating the environmental sustainability of plasma technology. The present paper highlights recent developments and provides new perspectives for the application of low temperature plasma in various areas, especially sterilization field of the food industry. Low temperature plasma holds great promise for the food industry's sterilization needs. Further research and technological advancements are required to fully harness its potential and ensure safe implementation across various food sectors.

Treatment of Ready-To-Eat Cooked Meat Products with Cold Atmospheric Plasma to Inactivate Listeria and Escherichia coli

Ready-to-eat meat products have been identified as a potential vehicle for Listeria monocytogenes. Postprocessing contamination (i.e., handling during portioning and packaging) can occur, and subsequent cold storage together with a demand for products with long shelf life can create a hazardous scenario. Good hygienic practice is augmented by intervention measures in controlling post-processing contamination. Among these interventions, the application of 'cold atmospheric plasma' (CAP) has gained interest. The reactive plasma species exert some antibacterial effect, but can also alter the food matrix. We studied the effect of CAP generated from air in a surface barrier discharge system (power densities 0.48 and 0.67 W/cm²) with an electrode-sample distance of 15 mm on sliced, cured, cooked ham and sausage (two brands each), veal pie, and calf liver pâté. Colour of samples was tested immediately before and after CAP exposure. CAP exposure for 5 min effectuated only minor colour changes (ΔE max. 2.7), due to a decrease in redness (a*), and in some cases, an increase in b*. A second set of samples was contaminated with Listeria (L.) monocytogenes, L. innocua and E. coli and then exposed to CAP for 5 min. In cooked cured meats, CAP was more effective in inactivating E. coli (1 to 3 log cycles) than Listeria (from 0.2 to max. 1.5 log cycles). In (non-cured) veal pie and calf liver pâté that had been stored 24 h after CAP exposure, numbers of E. coli were not significantly reduced. Levels of Listeria were significantly reduced in veal pie that had been stored for 24 h (at a level of ca. 0.5 log cycles), but not in calf liver pâté. Antibacterial activity differed between but also within sample types, which requires further studies.

Effect of Cold-Plasma-Treated Phosphate Solution to Substitute Partial Nitrite on the Color, Texture, and Flavor of Smoked Sausage

There are several alternative technologies to nitrite use in meat products, including cold plasma. In this study, a cold-plasma-treated phosphate solution was added to smoked sausage, as a new ingredient. Subsequently, the color, texture, and flavor of the samples were analyzed. The results showed that, compared with nitrite (0.075 g/kg nitrite added to sausage), the addition of 30~90% nitrite and cold-plasma-treated phosphate solution had no significant effect on the a* value or the relative content of oxygenated myoglobin (p > 0.05). The amount of residual nitrite in the smoked sausage prepared with the addition of 30~70% nitrite and cold-plasma-treated phosphate solution was significantly lower than that of the nitrite-treated group. The addition of nitrite combined with cold-plasma-treated phosphate solution had no significant effects on the texture (hardness, springiness, cohesiveness, and resilience) or the sensory evaluation of the smoked sausage. A total of 69 volatile compounds were detected, and 20 of them had VIP (Variable Importance Plot) scores higher than one. In conclusion, cold plasma treatment represents a potential technology to partially substitute nitrite. This study provides new methods for the application of this nitrite substitute.

Treatment of Fresh Meat, Fish and Products Thereof with Cold Atmospheric Plasma to Inactivate Microbial Pathogens and Extend Shelf Life

Assuring the safety of muscle foods and seafood is based on prerequisites and specific measures targeted against defined hazards. This concept is augmented by 'interventions', which are chemical or physical treatments, not genuinely part of the production process, but rather implemented in the framework of a safety assurance system. The present paper focuses on 'Cold Atmospheric pressure Plasma' (CAP) as an emerging non-thermal intervention for microbial decontamination. Over the past decade, a vast number of studies have explored the antimicrobial potential of different CAP systems against a plethora of different foodborne microorganisms. This contribution aims at providing a comprehensive reference and appraisal of the latest literature in the area, with a specific focus on the use of CAP for the treatment of fresh meat, fish and associated products to inactivate microbial pathogens and extend shelf life. Aspects such as changes to organoleptic and nutritional value alongside other matrix effects are considered, so as to provide the reader with a clear insight into the advantages and disadvantages of CAP-based decontamination strategies.

Plasma-activated milk powder as a sodium nitrite alternative in pork sausages

This study investigated the effect of plasma activated milk powder containing 1.3 g/kg nitrite as an alternative to sodium nitrite in stored pork sausages. Control samples (NC) did not contain a nitrite source, while the recipes of other treatments contained 100 ppm sodium nitrite (PC), 5% plasma activated milk powder (PAMP), and 5% plasma activated milk powder with 0.05% ascorbic acid (PAMP+AA). The obtained results showed both experimental groups were characterized by higher values of residual nitrite, nitrosylhemochrome and redness as well as similar or lower values of thiobarbituric acid reactive substances and total aerobic plate count compared to PC group after the storage period. Using ascorbic acid promoted reduction of nitrite content and extended the color stability of the samples compared to PAMP group without deteriorating the oxidative and microbiological quality of the product. Finally, sausages cured using the proposed alternative method exhibited higher cooking yield, lighter color, better texture, and different aroma profile (PCA) than those with sodium nitrite.

Green Technology for Pork Loin Wet Curing-Unconventional Use of Cow and Soy Milk Treated with Non-Thermal Atmospheric Plasma

This study was conducted to evaluate the possibility of using plasma-activated cow and soy milk powders as a substitute for sodium nitrite for wet curing of pork meat (m. longissimus thoracis et lumborum). Pork loin slices were cured for 4 d at refrigerate conditions in four brines: water + salt (NC group), water + salt + sodium nitrite (PC group), water + salt + plasma-activated cow milk powder (B1 group), and water + salt + plasma-activated soy milk powder (B2 group). Importantly, brines from groups PC, B1, and B2 were characterized by the same concentration of NO2− ions (200 ppm). Results show that samples from B1 and B2 groups had significantly (p < 0.05) higher values of redness, nitrosylhemochrome content, and lower values of thiobarbituric acid reactive substances (TBARS) compared to samples from the NC group. At the same time, the groups cured with alternative curing agents were characterized by lower residual nitrite content with regard to groups cured with NaNO2. No significant differences (p ≥ 0.05) were found in pH and shear force values among the treatments. Finally, the aroma profile of the samples from groups B1 and B2 was similar to the aroma profile of the samples from the PC group (the aroma differed by a maximum of 1.73% in the case of brine containing plasma-activated cow milk powder) but differed significantly from the NC group (the aroma differed in 97.21%). Due to the higher nitrite depletion in the final product, while maintaining the quality parameters similar to traditionally cured pork loins, both alternative curing agents can be recommended, with a predominance of plasma-treated soy milk.

Plasma-Activated Water for Food Safety and Quality: A Review of Recent Developments

Plasma-activated water (PAW) has received a lot of attention lately because of its antibacterial efficacy and eco-friendly nature. Compared to traditional disinfectants, this novel and intriguing option has a high disinfectant capacity while causing little to no modifications to the foodstuffs. Until now, PAW has successfully demonstrated its effectiveness against a broad range of microorganisms on a wide variety of food items. Though the efficacy of PAW in microbial reduction has been extensively reviewed, a relatively significant issue of food quality has been largely overlooked. This review aims to summarize the current studies on the physicochemical characteristics and antimicrobial potential of PAW, with an in-depth focus on food quality and safety. According to recent studies, PAW can be a potential microbial disinfectant that extends the shelf life of various food products, such as meat and fish products, fruits and vegetables, cereal products, etc. However, the efficacy varies with treatment conditions and the food ingredients applied. There is a mixed opinion about the effect of PAW on food quality. Based on the available literature, it can be concluded that there has been no substantial change in the biochemical properties of most of the tested food products. However, some fruits and vegetables had a higher value for the enzyme superoxide dismutase (SOD) after PAW treatment, while only a few demonstrated a decrease in the Thiobarbituric acid reactive substances (TBARS) value. Sensory properties also showed no significant difference, with some exceptions in meat and fish products.

Plasma bioscience for medicine, agriculture and hygiene applications

Nonthermal biocompatible plasma (NBP) sources operating in atmospheric pressure environments and their characteristics can be used for plasma bioscience, medicine, and hygiene applications, especially for COVID-19 and citizen. This review surveyed the various NBP sources, including a plasma jet, micro-DBD (dielectric barrier discharge) and nanosecond discharged plasma. The electron temperatures and the plasma densities, which are produced using dielectric barrier discharged electrode systems, can be characterized as 0.7 ~ 1.8 eV and (3-5) × 1014-15 cm-3, respectively. Herein, we introduce a general schematic view of the plasma ultraviolet photolysis of water molecules for reactive oxygen and nitrogen species (RONS) generation inside biological cells or living tissues, which would be synergistically important with RONS diffusive propagation into cells or tissues. Of the RONS, the hydroxyl radical [OH] and hydrogen peroxide H2O2 species would mainly result in apoptotic cell death with other RONS in plasma bioscience and medicines. The diseased biological protein, cancer, and mutated cells could be treated by using a NBP or plasma activated water (PAW) resulting in their apoptosis for a new paradigm of plasma medicine.

Application of Water Treated with Low-Temperature Low-Pressure Glow Plasma (LPGP) in Various Industries

Plasma processing is now a key technology across the world, and nonthermal low-temperature plasmas are being increasingly used. This situation can be explained by a rapidly growing interest in the optimization of existing methods, as well as the development of new ones. Over the last few years, the production of plasma-treated water (PTW) by low-temperature low-pressure glow plasma (LPGP) under an atmosphere of various gases has been increasingly gaining in popularity. Research has been conducted on producing plasma-treated water in the presence of air, nitrogen, ammonia, carbon dioxide, and methane. All the obtained results show that the changed physicochemical properties of the water depend on the type of gas used and the duration of the plasma treatment. New research is emerging on the possibility of using this water in plant breeding, animal husbandry, cosmetology, medicine, and food. For the first time, plasma-treated water has also been tested for use in the brewing industry at the raw material preparation stage. The results obtained in all branches of science are very promising, contributing to the growing interest in plasma-treated water within the scientific community.

Toxicity Assessment of Long-Term Exposure to Non-Thermal Plasma Activated Water in Mice

Non-thermal plasma activated water (PAW) has recently emerged as a powerful antimicrobial agent. Despite numerous potential bio-medical applications, studies concerning toxicity in live animals, especially after long-term exposure, are scarce. Our study aimed to assess the effects of long-term watering with PAW on the health of CD1 mice. PAW was prepared from distilled water with a GlidArc reactor according to a previously published protocol. The pH was 2.78. The mice received PAW (experimental group) or tap water (control group) daily for 90 days as the sole water source. After 90 days, the following investigations were performed on the euthanatized animals: gross necropsy, teeth mineral composition, histopathology, immunohistochemistry, hematology, blood biochemistry, methemoglobin level and cytokine profile. Mice tolerated PAW very well and no adverse effects were observed during the entire period of the experiment. Histopathological examination of the organs and tissues did not reveal any structural changes. Moreover, the expression of proliferation markers PCNA and Ki67 has not been identified in the epithelium of the upper digestive tract, indicating the absence of any pre- or neoplastic transformations. The results of our study demonstrated that long-term exposure to PAW caused no toxic effects and could be used as oral antiseptic solution in dental medicine.

Potential Alternative to Nitrite in Roasted Lamb for Sensory Attributes: Atmospheric Nonthermal Plasma Treatment

Reducing or replacing sodium nitrite without compromising the sensory attributes of meat products has always been a focus of the meat industry. In this study, five treatments, CT (without nitrite and plasma treatment), NT (with nitrite treatment), PT15, PT30, and PT45 (without nitrite and with plasma treatment for 15, 30, and 45 min, respectively), were designed to investigate the effect of atmospheric nonthermal plasma treatment replacing nitrite on the sensory attributes of roasted lamb. Results showed that PT45 decreased the residual nitrite of roasted lamb by 30% compared with NT, and nitrite was not detected in the PT15 and PT30 samples. The inhibition effect of plasma treatment on the lipid oxidation reached values from 86.69% to 89.89% compared with NT. Compared with CT, the redness of plasma-treated samples was increased by 9.30% to 31.40%, and the redness of NT samples was increased by 30.87%. In addition, the volatile compounds (OAVs > 1) of the PT30 sample were higher than those of the NT sample. The overall sensory score of the PT30 sample was higher than that of the CT sample and was similar to that of the NT samples. In conclusion, the sensory attributes of roasted lamb were enhanced by plasma treatment, and the 30 min plasma treatment is recommended.

Plasma bioscience and its application to medicine

Nonthermal atmospheric pressure biocompatible plasma (NBP), alternatively called bio-cold plasma, is a partially ionized gas that consists of charged particles, neutral atoms and molecules, photons, an electric field, and heat. Recently, nonthermal plasma-based technology has been applied to bioscience, medicine, agriculture, food processing, and safety. Various plasma device configurations and electrode layouts has fast-tracked plasma applications in the treatment of biological and material surfaces. The NBP action mechanism may be related to the synergy of plasma constituents, such as ultraviolet radiation or a reactive species. Recently, plasma has been used in the inactivation of viruses and resistant microbes, such as fungal cells, bacteria, spores, and biofilms made by microbes. It has also been used to heal wounds, coagulate blood, degrade pollutants, functionalize material surfaces, kill cancers, and for dental applications. This review provides an outline of NBP devices and their applications in bioscience and medicine. We also discuss the role of plasma-activated liquids in biological applications, such as cancer treatments and agriculture. The individual adaptation of plasma to meet specific medical requirements necessitates real-time monitoring of both the plasma performance and the target that is treated and will provide a new paradigm of plasma-based therapeutic clinical systems.

Alternative Curing Methods

Purpose of Review

Curing—the treatment of meat products with nitrite and nitrate—is controversially discussed by consumers, as increased consumption of cured foods might negatively influence human health.

Recent Findings

However, omitting of curing chemicals might reduce microbiological safety, thereby increasing the risk to consumer health. Also, besides the addition of nitrate/nitrite, meat products are additionally preserved within the hurdle principle by other methods such as chilling, ripening, or heating.

Summary

The present article focuses on the addition of plants/plant extracts or plasma-treated water as nitrate sources and the direct treatment of meat products with plasma for nitrate generation. With regard to color and microbial safety of cured meat products, which are relevant to the consumers, promising results were also obtained with the alternative curing methods. Nonetheless, it is doubtful to what extent these methods are viable alternatives, as the curing chemicals themselves and not their origin are problematic for consumer health.

Effects of plasma activated solution on the colour and structure of metmyoglobin and oxymyoglobin

Effects of plasma-activated solution (PAS) on the colour and structure of metmyoglobin (metMb) and oxymyoglobin (oxyMb) were investigated and the relationship between discolouration and structure changes was clarified for the first time. Results showed that the colour of PAS-treated metMb faded first, followed by green discolouration, while PAS-treated oxyMb turned from bright red to reddish-brown and then towards green in the end. It was due to the accumulation of H₂O₂, nitrite and nitrate in PAS with prolonging plasma treatment times. Also, the low concentrations of active species in PAS cannot influence the colour and structure of metMb and oxyMb. The accumulation of active species of H₂O₂ in PAS was the main reason for destructing myoglobin structure and transforming its colour with prolonging treatment time. Therefore, the concentration of H₂O₂ should be adjusted to a low level for treating red meats as their colour appearance is mainly determined by metMb and oxyMb.

Potential Use of Hyssopus officinalis and Borago officinalis as Curing Ingredients in Pork Meat Formulations

Simple Summary

Health risks associated with nitrites as curing agents have led consumers to search for products without those additives. Herbs have been used in medicine for many years and are usually positively perceived by consumers. Good-quality products with medicinal plants may be an alternative for those who try to avoid additives other than salt and spices. Hyssopus officinalis and Borago officinalis were tested for their potential to be used as colour forming and antioxidant agents. Both herbs were used in pork meat formulations along with nitrate reducing bacteria. A colour formation similar to a control product containing nitrite was noted in all the samples. Borage had a stronger antioxidant effect. Those additives can be used as an alternative to nitrite cured pork products.

Abstract

The replacement of nitrites in pork meat products has been a studied issue for many years. Due to potential health threats associated with these additives, consumers tend to search for alternative meat curing methods. In this study, Hyssopus officinalis and Borago officinalis were tested for their potential to be used as colour-forming and antioxidant agents. Dry plant samples from various sources were tested for fat, protein, ash, polyphenol and nitrate content. There were significant differences between the herbs depending on source. Two control samples (containing curing salt and sodium chloride with nitrate reducing bacteria) and samples with herbs (hyssop, hyssop with nitrate reducing bacteria, borage, borage with nitrate reducing bacteria)—0.5% of the meat mass—were prepared and stored for 15 days. In the samples with herbs and bacterial cultures, a red colour was developed, the TBARS values were low and DPPH activity was strong. All the samples with herbs had lower residual nitrite levels compared to the samples with curing salt. Borage had a stronger influence on colour and antioxidant stability of the meat samples compared to hyssop. However, both herbs can be used as colour-forming and antioxidant agents along with nitrate-reducing bacteria.

A review on recent advances in plasma-activated water for food safety: current applications and future trends

Plasma-activated water (PAW), the water or solutions treated with atmospheric cold plasma, is an eco-friendly technique with minimal changes in food products, making it a befitting alternative to traditional disinfection methods. Due to its potential microbicidal properties, PAW has been receiving increasing attention for applications in the food, agricultural, and biomedical fields. In this article, we aimed at presenting an overview of recent studies on the generation methods, physicochemical properties, and antimicrobial activity of PAW, as well as its application in the food industry. Specific areas were well discussed including microbial decontamination of food products, reduction of pesticide residues, meat curing, sprouts production, and disinfection of food contact materials. In addition, the factors influencing PAW efficiency were also well illustrated in detail, such as discharge parameters, types and amounts of microorganisms, characteristics of the liquid solution and food products, and treatment time. Moreover, the strategies to improve the efficacy of PAW were also presented in combination with other technologies. Furthermore, the salient drawbacks of this technology were discussed and the important areas for future research were also highlighted. Overall, the present review provides important insights for the application of PAW in the food industry.

Nonthermal plasma-activated water: A comprehensive review of this new tool for enhanced food safety and quality

Nonthermal plasma (NTP) is an advanced technology that has gained extensive attention because of its capacity for decontaminating food from both biological and chemical sources. Plasma-activated water (PAW), a product of NTP's reaction with water containing a rich diversity of highly reactive oxygen species (ROS) and reactive nitrogen species (RNS), is now being considered as the primary reactive chemical component in food decontamination. Despite exciting developments in this field recently, at present there is no comprehensive review specifically focusing on the comprehensive effects of PAW on food safety and quality. Although PAW applications in biological decontamination have been extensively evaluated, a complete analysis of the most recent developments in PAW technology (e.g., PAW combined with other treatments, and PAW applications in chemical degradation and as curing agents) is nevertheless lacking. Therefore, this review focuses on PAW applications for enhanced food safety (both biological and chemical safeties) according to the latest studies. Further, the subsequent effects on food quality (chemical, physical, and sensory properties) are discussed in detail. In addition, several recent trends of PAW developments, such as curing agents, thawing media, preservation of aquatic products, and the synergistic effects of PAW in combination with other traditional treatments, are also presented. Finally, this review outlines several limitations presented by PAW treatment, suggesting several future research directions and challenges that may hinder the translation of these technologies into real-life applications.

Plasma-activated water: Physicochemical properties, microbial inactivation mechanisms, factors influencing antimicrobial effectiveness, and applications in the food industry

Novel nonthermal inactivation technologies have been increasingly popular over the traditional thermal food processing methods due to their capacity in maintaining microbial safety and other quality parameters. Plasma-activated water (PAW) is a cutting-edge technology developed around a decade ago, and it has attracted considerable attention as a potential washing disinfectant. This review aims to offer an overview of the fundamentals and potential applications of PAW in the agri-food sector. A detailed description of the interactions between plasma and water can help to have a better understanding of PAW, hence the physicochemical properties of PAW are discussed. Further, this review elucidates the complex inactivation mechanisms of PAW, including oxidative stress and physical effect. In particular, the influencing factors on inactivation efficacy of PAW, including processing factors, characteristics of microorganisms, and background environment of water are extensively described. Finally, the potential applications of PAW in the food industry, such as surface decontamination for various food products, including fruits and vegetables, meat and seafood, and also the treatment on quality parameters are presented. Apart from decontamination, the applications of PAW for seed germination and plant growth, as well as meat curing are also summarized. In the end, the challenges and limitations of PAW for scale-up implementation, and future research efforts are also discussed. This review demonstrates that PAW has the potential to be successfully used in the food industry.

Quality characteristics and protein digestibility of Protaetia brevitarsis larvae

Herein, the in vitro protein digestibility of lyophilized Protaetia brevitarsis larvae flour with and without defatting using 70% ethanol was compared with beef loin. Proximate analysis showed that the defatted larvae contained the highest protein content (p < 0.05). The viable counts of total aerobic bacteria, Escherichia coli, and coliform bacteria decreased significantly after defatting the larval samples with 70% ethanol (p < 0.05). Measurement of α-amino group content and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed higher amounts of low molecular weight proteins in the larvae compared to beef loin (p < 0.05). After in vitro digestion, the degree of protein hydrolysis of the digesta was higher for both larvae samples compared to beef loin (p < 0.05). No change was observed in the in vitro larval protein digestibility after defatting. These results highlight the excellent protein digestibility of P. brevitarsis larvae with high protein content. Defatting insect flour with 70% ethanol could enhance microbial safety while maintaining excellent protein digestibility.

Non-thermal plasma: An advanced technology for food industry

In this era of green technology, plasma technology is one of the novel techniques intended towards many industries including food industry as a principal application due to less utilization of energy, solvents, and water with minimum impact on food quality. The foremost purpose behind the utilization of nonthermal plasma processing (cold plasma) lies in the retention of freshness of food products along with furtherance of sensory properties as well as functional and nutritional composition. In addition, this technique assists in shelf life extension and carries out desirable modifications in the structure of food and packaging material. This technology has been proven to be advantageous over other technologies since all these processes are carried out at low temperature, hence is highly suitable for heat-sensitive materials. The present review summarizes the mechanism of this plasma technology along with its benefits to the industry, for example improvements in cooking quality, enhancements in enzyme activity, modification of starches, and microbial inactivation. Also, the effects of plasma treatment on characteristics of various food products have been elaborated in this review.

Functionalization of water as a nonthermal approach for ensuring safety and quality of meat and seafood products

Meat and seafood products present a viable medium for microbial propagation, which contributes to foodborne illnesses and quality losses. The development of novel and effective techniques for microbial decontamination is therefore vital to the food industry. Water presents a unique advantage for large-scale applications, which can be functionalized to inactivate microbial growth, ensuring the safety and quality of meat and seafood products. By taking into account the increased popularity of functionalized water utilization through electrolysis, ozonation and cold plasma technology, relevant literature regarding their applications in meat and seafood safety and quality are reviewed. In addition, the principles of generating functionalized water are presented, and the safety issues associated with their uses are also discussed.Functionalization of water is a promising approach for the microbiological safety and quality of meat and seafood products and possesses synergistic effects when combined with other decontamination approaches. However, functionalized water is often misused since the active antimicrobial component is applied at a much higher concentration, despite the availability of applicable regulations. Functionalized water also shows reduced antimicrobial efficiency and may produce disinfection by-products (DBPs) in the presence of organic matter, especially at a higher concentration of active microbial component. Utilization should be encouraged within regulated guidelines, especially as hurdle technology, while plasma functionalized water which emerges with great potentials should be exploited for future applications. It is hoped that this review should encourage the industry to adopt the functionalized water as an effective alternative technique for the food industry.

Nonthermal Plasma-Induced Degradation of Morin and Enhancement of Biological Activities

In the present study, non-thermal dielectric barrier discharge (DBD) plasma of induced structural changes of morin resulted in the isolation of one previously undescribed benzofuranone derivative, along with two known compounds. The chemical structures of these degradation products were elucidated by UV, NMR and FAB-MS spectroscopic analyses. The isolated three compounds showed potent antioxidative activities in two different tests, with IC₅₀ values in the range of 12.9-41.8 μm in the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺ ) radical scavenging activity, 19.0-71.9 μm for hydroxyl radical scavenging activity test. Furthermore, the new methoxylated benzofuranone exhibited enhancement of inhibitory effects against pancreatic lipase with an IC₅₀ value of 90.7±1.6 μm, when compared to the parent morin. These results suggested that the degradation products isolated from plasma exposed morin might be beneficial for prevention of obesity and related diseases.