Amount Of Nitrite Research Articles

Optimizing nitrite content in powders from plasma-activated egg whites for meat preservation using response surface methodology

The study optimized the production of powders from two types of egg whites to be used as a nitrite source for meat curing, establishing a maximum utilization limit of 2%. The necessary quantity of nitrite was established through response surface methodology to guarantee its efficacy as a preservative agent and adherence to regulatory standards. High R2 values (0.9946 for hen, 0.9962 for ostrich) validated critical factors: plasma treatment time and distance, with minimal impact from drying temperature. Under specific experimental conditions (155.93 min, 16.84 cm, 41.10 °C), obtained nitrite concentration of 4000 mg kg⁻1 was confirmed through experiments. Stability tests showed that nitrite levels remained stable over four weeks under different conditions including vacuum and air-sealed packaging, as well as different temperatures (−18 °C, 4 °C, and 26 °C). Future research should investigate long-term stability, the formation of additional compounds, and the functional properties of powders to confirm their potential for food applications.

DYNAMIC EFFECTS OF ANAEROBIC FERMENTATION ON PROTEIN, FLAVONOIDS, NITRATE, AND NITRITE CONTENT AND BIOACTIVITIES OF MATURE LEAVES OF TOONA SINENSIS

Toona sinensis (TS) is a widely cultivated and economically valued tree in Asia. However, millions of tons of its nutritious mature leaves go unutilized due to excessive amount of nitrate and nitrite. In this study, the mature leaves of TS were chopped, vacuum-packed, and fermented for up to 18 weeks to evaluate their feeding potential. The dynamic effects of fermentation on quality indicators, including crude protein, flavonoids, nitrate and nitrite content, and antioxidant activity [radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ferric-reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC)] of mature leaves of TS were quantified every two weeks. Results showed that after fermentation for 6 weeks, the total content of nitrate and nitrite of TS leaves was significantly decreased (p ≤ 0.05) from 4523.36 to 1102.20 mg/kg. The mean content of nutritional components, including crude protein (17.88 ± 0.49%), flavonoids (792.24 ± 50.78 mg/100 g), and antioxidant activity (317.62 ± 44.70 mg/100 g for DPPH, 400.44 ± 25.87 mg/100 g for FRAP, 473.74 ± 37.17 μM/g for ORAC) of TS leaves were well preserved between 6 to 14 weeks of fermentation. These results indicated that fermentation may provide a new way to utilize TS resources, and the fermented mature leaves of TS could be a novel, valuable feed supplement, especially for ruminants. Screening and inoculating TS leaves with an appropriate starter culture, such as lactic acid bacteria inoculants, during fermentation is recommended to further improve TS feed quality. Keywords: Feed, Quality, Nitrate and nitrite, Flavonoid, Antioxidant activity.

Dietary Nitrate Metabolism in Porcine Ocular Tissues Determined Using 15N-Labeled Sodium Nitrate Supplementation.

Nitrate (NO3-) obtained from the diet is converted to nitrite (NO2-) and subsequently to nitric oxide (NO) within the body. Previously, we showed that porcine eye components contain substantial amounts of nitrate and nitrite that are similar to those in blood. Notably, cornea and sclera exhibited the capability to reduce nitrate to nitrite. To gain deeper insights into nitrate metabolism in porcine eyes, our current study involved feeding pigs either NaCl or Na15NO3 and assessing the levels of total and 15N-labeled NO3-/NO2- in various ocular tissues. Three hours after Na15NO3 ingestion, a marked increase in 15NO3- and 15NO2- was observed in all parts of the eye; in particular, the aqueous and vitreous humor showed a high 15NO3- enrichment (77.5 and 74.5%, respectively), similar to that of plasma (77.1%) and showed an even higher 15NO2- enrichment (39.9 and 35.3%, respectively) than that of plasma (19.8%). The total amounts of NO3- and NO2- exhibited patterns consistent with those observed in 15N analysis. Next, to investigate whether nitrate or nitrite accumulate proportionally after multiple nitrate treatments, we measured nitrate and nitrite contents after supplementing pigs with Na15NO3 for five consecutive days. In both 15N-labeled and total nitrate and nitrite analysis, we did not observe further accumulation of these ions after multiple treatments, compared to a single treatment. These findings suggest that dietary nitrate supplementation exerts a significant influence on nitrate and nitrite levels and potentially NO levels in the eye and opens up the possibility for the therapeutic use of dietary nitrate/nitrite to enhance or restore NO levels in ocular tissues.

Phenolic profile and chronic gastric ulcer healing effects of Cameroonian propolis

BackgroundGastric ulcers continue to affect millions of people worldwide, with reported cases of fatalities and the diagnosis, prevention and treatment constitute a burden on the patients especially in case of chronic ulcers which are difficult to treat. Natural medicines such as propolis provide suitable therapeutic alternatives in the treatment and curation of ulcers. ObjectiveThis work focused on the evaluation of the phenolic profile and healing effect of Cameroonian propolis on gastric ulcers in rats. MethodsIdentification and quantification of phenolic compounds in the propolis extract was done using HPLC-DAD. Chronic gastric ulcers were induced using ethanol (70%; 1 mL/200 g p.o.)/indomethacin (1 mg/kg p.o.), and “unhealed” gastric ulcerations were induced using acetic acid (30%)/indomethacin (1 mg/kg p.o.). The animals were administered with the vehicle (Tween 20, 1 mL/100 g p.o.), propolis extract (200 mg/kg, 400 mg/kg and 600 mg/kg p.o.) or sucralfate (50 mg/kg p.o.), once daily for ten to fourteen days. At the end of each treatment period, the animals were sacrificed and ulcer indices, gastric mucus weight, histological and oxidative stress parameters were assessed. ResultsEight phenolic compounds were identified and quantified and most abundant were Caffeic acid (45.31 ± 0.25 µg/g), Chrysin (37.65 ± 0.17 µg/g) and p-Hydroxy benzoic acid (34.14 ± 0.21 µg/g). The treatment of ulcerated rats (chronic and unhealed gastric ulcer models) with propolis extract at 200 mg/kg, 400 mg/kg and 600 mg/kg resulted in reduction of ulcer index compared to negative controls in both models. Histological observation of stomach tissues showed that treatment with propolis extract led to a dose-dependent normalization of the mucosa. There was a significant increase (P < 0.05; P < 0.01 and P < 0.001) in mucus weight that accompanied the healing of the ulcers. Furthermore, doses of 200 mg/kg, 400 mg/kg and 600 mg/kg of the propolis extract induced an increase in the amounts of SOD, catalase, nitrite and GSH while MDA concentrations decreased in both models. ConclusionThe healing effect of propolis extract is due to the stimulation of mucus production followed by an improvement of in vivo antioxidant status. These results support the use of propolis in the development of new pharmacological strategies for the management of peptic ulcers disease.

Determination of the nutritional and biological value of semi-smoked sausage products made from beef

Sausage products belong to high-calorie products with their own taste and aroma and occupy a significant share in the meat products market of Kazakhstan. In the modern era, one of the most important directions in the creation of technology for meat products is to reduce the content of toxic substances in products and enrich their composition with vitamins, macro - and microelements through natural raw materials. The presented article shows the result of improving the quality indicators of finished products by adding vegetables to them in order to expand the range of semi-smoked beef sausages. Sausage products are meat products made from minced meat and heat – treated, their chemical composition and nutritional value are higher depending on the portion content, i.e. the content of complete proteins, irreplaceable polyunsaturated fatty acids, macro- and microelements and vitamins in the finished product the composition in the sausage recipe depends on the type and size of the portion. In the course of scientific work, it is planned to increase the nutritional and biological value of sausage by reducing the amount of nitrites and spices used in the production of sausages and adding vitamin-rich carrot juice instead. Carrot juice is a real depository of useful vitamins, micro and macroelements, and the antioxidants contained in it are able to prevent the appearance and development of malignant tumors. Especially vitamin A, which is contained in carrots, is characterized by strong antioxidant properties, it is formed from carotene, which enters our body, and it is easily absorbed through squeezed carrot juice. As a result of research, a recipe for new samples of semi-smoked sausages with the addition of carrot juice was created, a production technology was developed, and the nutritional and biological value of the resulting sausage product was determined. Carrot juice contributed to the formation of aroma, taste, color and high-quality characteristics of sausages.

Enhancing quality control in emulsion-type sausage production: Predicting chemical composition of intact samples with near infrared spectroscopy

This research actively explores the potential of near infrared spectroscopy (NIR) for analyzing the chemical composition of emulsion-type sausages, focusing on critical factors like residual nitrite, moisture, protein, and fat content. To establish robust and generalizable models, we utilized a dataset of 100 experimentally prepared sausages encompassing a wide range of pork back fat replacement levels (5%, 15%, 30%, 45%, and 60%) and added sodium nitrite amounts (0, 80, 125, 250, and 375 ppm). An external validation set of 20 commercially sourced sausages further assessed the model’s real-world applicability. Partial least squares (PLS) regression calibration models with multiplicative scatter correction (MSC) pre-treatment demonstrated impressive accuracy for moisture (RMSECV = 0.57%, RPD = 9.8), fat (RMSECV = 1.17%, RPD = 9.5), and protein (RMSECV = 0.30%, RPD = 7.6). While residual nitrite prediction presented challenges due to its inherent complexity, the external validation yielded a competitive root mean square error of prediction (RMSEP) of 12.02 ppm, surpassing the average performance reported in similar studies (RMSEP ∼15 ppm) by 3 ppm. Importantly, sample homogenization did not significantly affect parameter prediction, highlighting the robustness of the NIR-based approach. These findings suggest that NIR spectroscopy, with its non-destructive, rapid, and cost-effective nature, could provide valuable tools for quality control and monitoring in the emulsion-type sausage industry. More importantly, improved nitrite prediction could pave the way for enhanced precision and control in sausage production, ultimately contributing to improved food safety and sustainability.

Global transcriptome analysis reveals Salmonella Typhimurium employs nitrate metabolism to combat bilestress.

Salmonella Typhimurium is an enteric pathogen that is highly tolerant to bile. Next-generation mRNA sequencing was performed to analyze the adaptive responses to bile in two S. Typhimurium strains: wild type (WT) and a mutant lacking cold shock protein E (ΔcspE). CspE is an RNA chaperone which is crucial for survival of S. Typhimurium during bile stress. This study identifies transcriptional responses in bile-tolerant WT and bile-sensitive ΔcspE. Upregulation of several genes involved in nitrate metabolism was observed, including fnr, a global regulator of nitrate metabolism. Notably, Δfnr was susceptible to bile stress. Also, complementation with fnr lowered reactive oxygen species and enhanced the survival of bile-sensitive ΔcspE. Importantly, intracellular nitrite amounts were highly induced in bile-treated WT compared to ΔcspE. Also, the WT strain pre-treated with nitrate displayed better growth with bile. These results demonstrate that nitrate-dependent metabolism promotes adaptation of S. Typhimurium to bile.

Distribution of nitrate/nitrite and toxic metals in the soil-potato system and its health risk assessment in Iran.

Potato is one of the essential food products whose health quality is greatly influenced by soil contamination and properties. In the current study, we have investigated the physicochemical characteristics of agricultural areas and the accumulation of nitrite/nitrate and metals in potato products in Hamedan, Iran. After determining the physicochemical characteristics of soil samples from four agricultural regions of Hamedan, 48 potato samples were collected from these regions. The heavy metals and nitrate/nitrite content were determined by ICP-OES and calorimetric methods, respectively. A negative correlation was observed between soil pH changes with nitrite/nitrate content and the accumulation of some heavy elements in potatoes. Furthermore, a positive correlation was found between soil phosphorus content and lead accumulation in potato. In present study, the amounts of lead, nitrate, and nitrite in 83.3%, 56%, and 12% of the collected samples were higher than the permissible limit reported by the World Health Organization (WHO), respectively. The EDI range for nitrate and nitrite was determined to be 130-260 and 1.4-2.7µg/kg/day, respectively, which is much lower than the RfD set by the US Environmental Protection Agency (USEPA) for nitrite and nitrate. Among metal pollutants, the toxic risk caused by lead in potato consumers was higher than the threshold limit. In conclusion, our findings showed that the physicochemical characteristics of the soil could effectively increase the availability of metal pollutants and nitrite/nitrate to the potato product and significantly reduce its health quality. Therefore, monitoring these pollutants in the soil-potato system, preventing the entry of industrial wastewater, and managing the use of agricultural fertilizers can effectively improve the health of this product for consumers.

Ivermectin Exerts Anticonvulsant Effects Against Status Epilepticus Induced by Lithium-Pilocarpine in Rats via GABAA Receptor and Neuroinflammation Modulation: Possible Interaction of Opioidergic Pathways and KATP Channel with Nitrergic System.

Status epilepticus (SE) is a critical medical emergency marked by persistent or rapidly repeating seizures, posing a threat to life. Using the lithium-pilocarpine-induced SE model, we decide to evaluate the anti-seizure effects of ivermectin as a positive allosteric modulator of GABAA receptor and the underlying mechanisms involved. Lithium chloride was injected intraperitoneally at a dose of 127 mg/kg, followed by the administration of pilocarpine at a dose of 60 mg/kg after a 20-h interval in order to induce SE. Subsequently, the rats received varying amounts of ivermectin (0.3, 1, 3, 5, and 10 mg/kg, i.p.) 30 min before the onset of SE. To study the underlying molecular mechanisms, we had pharmacological interventions of diazepam (1 mg/kg), glibenclamide and nicorandil as ATP-sensitive potassium channel blocker and opener (both 1 mg/kg, i.p.), naltrexone and morphine, as opioid receptor antagonist and agonist (1 mg/kg and 0.5 mg/kg, i.p., respectively). In addition, three nitric oxide inhibitors, namely, L-NAME (10 mg/kg, i.p.), 7-NI (30 mg/kg, i.p.), and aminoguanidine (100 mg/kg, i.p.), were administered to the rats in the experiment. Finally, we use ELISA and western blotting, respectively, to examine the amounts of pro-inflammatory cytokines (TNF-α and IL-1β), nitrite, and GABAA receptors in the rat hippocampal tissue. The study found that ivermectin, at doses of 3, 5, and 10 mg/kg, exerts anti-seizure effects and decrease Racine's scale SE score. Interestingly glibenclamide and naltrexone reduced the anti-seizure effects of ivermectin, and from other hand diazepam, nicorandil, morphine, L-NAME, 7-NI, and aminoguanidine, enhance the effects when co-administrated with subeffective dose of ivermectin. Additionally, the study found that ivermectin decreased the elevated levels of TNF-α and IL-1β following SE, while increased the reduced expression of GABAA receptors. Overall, these findings suggest that ivermectin has anti-seizure effects in a SE seizure which may be mediated by the modulation of GABAergic, opioidergic, and nitrergic pathways and KATP channels.

Effects Of Sodium Nitrite, Potassium Sorbate And α-Tocopherol On Residual Nitrite, Formations Of Biogenic Amines And N-Nitrosamines In Turkish Dry Fermented Sausage (Sucuk)

The effects of sodium nitrite, α-tocopherol and potassium sorbate on ion contents, biogenic amine (BA) and N-nitrosamine (NA) formations of Turkish type fermented sausage after storage were investigated based on Response Surface Methodology (RSM). In addition, relationships between ions, BAs and NAs were evaluated. Nitrite (NO2-) and ammonium (NH4+) ion amounts in all sausage samples were below limit of detection. The effects of factors are partially effective on the formation of nitrate (NO3-), BAs and NAs. There was a positive correlation between NO3- and N-nitrosodiethylamine (NDEA), and no correlation between other ions and BAs. The accumulations of tryptamine (TRP), tyramine (TyR) and spermidine (SPD) increased formations of NDEA, N-nitrosodi-n-propylamine (NDPA) and N-nitrosomorpholine (NMOR), respectively. It is concluded co-addition of sodium nitrite and potassium sorbate and/or α-tocopherol in fermented sausage production can significantly reduce amount of residual nitrite, thus inhibiting NAs.

Rapid colorimetric assay based on the oxidation of 2,2-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid-diammonium salt for nitrite detection in meat products

This work developed a rapid colorimetric method for nitrite detection in meat products. The detection was based on the reaction of nitrite with 60 mM HCl to produce radicals which further oxidized ABTS (50 µM) to form a water-soluble blue-green product (ABTS•+). The absorbance was measured at a maximum absorption wavelength of 412.5 nm. Parameters such as concentration of HCl, concentration of ABTS and reaction time were evaluated. The absorbance was linearly proportional to the concentration of nitrite (0.1–20 µM) with the limit of detection of 0.34 µM. The proposed method was a time-saving assay since it required only 2 min to complete one measurement. There was no effect of the interference produced by other ions. The assay was robust with 2.5%RSD (n = 50). In meat product samples, high accuracy was observed with the recoveries between 100 ± 2.2% and 105 ± 3.7%. The amount of nitrite in meat products detected by the ABTS method was found in the range of 5.41 − 7.62 mg/kg. The conventional Griess method was applied to determine nitrite in the same meat products. There was no statistically significant difference between the two methods (P = 0.05).

Influence of propionic acid microorganisms on the quality indicators of the produced sausage

The article considered the effect of probiotic bacteria on the quality of meat for semi-smoked sausages. The biochemical activity of propionic acid bacteria was studied at the stage of the production process of semi-smoked sausages after the treatment of raw materials with starter microorganisms. We also studied the effect of salt, and sodium nitrite on the development of propionic acid bacteria in raw beef. The results of the technology of production of semi-smoked sausages treated with propionic acid bacteria in the amount of 0.1%, and the quality characteristics of the finished sausage products are presented. On the basis of experimental studies optimal technological parameters of salting and precipitation in the production of fermented semi-smoked sausages were selected. The use of liquid propionic acid bacteria (2 strains of propionic acid bacteria Propionibacterium shermani) in the amount of 0.1% will give a decrease in the production time of half-smoked sausages by two times. As a result of the research it was proved that the introduction of 2 different strains of propionic acid bacteria concentrate into raw meat accelerates biochemical changes in the process of salting and provides functional and technological properties. Also, the results of the study showed that propionic acid bacteria used in the technology of semi-smoked sausages are resistant to the amount of food salts and sodium nitrite used. As a result of research, a better way of using liquid propionate microorganism in the production of semi-smoked fermented sausages was adopted.

Photosynthetic Bacteria as an Alternative Wastewater Treatment in Freshwater Aquarium Fish Set Up

Waste produced from aquaculture ultimately hampered the water quality and growth performance of species cultured. Therefore, the potential exploitation of photosynthetic bacteria (PSB) from aquaculture waste was investigated to treat the wastewater in the fish culture. In this study, the wastewater was collected from a fishpond and cultured in sunlight-exposed sterile bottles for 14 days. In the water additive experiment, five treatments (in a 30 cm3 aquarium) were prepared namely cultured PSB (T1), aquatic plant hornwort (T2), aquatic plant salvinia (T3), positive control (P), and negative control (N). Five individuals of Hyphessobrycon herbertaxelrodi (2.5±0.5 cm length) were placed in each treatment and reared for 30 days. Meanwhile, for the wastewater treatment, four treatments (in a 30 cm3 aquarium) were prepared namely wastewater from the hatchery fishpond (S1), wastewater from the hatchery fish tank (S2), positive control (P), and negative control (N). The results obtained indicate that T1 treatment significantly improved and maintained the water quality as compared to other treatments. The results showed the amount of ammonia and nitrite in S1 and S2 supplied with T1 for 30 days gradually decreased from day 1 until day 18. While zero amount of ammonia and nitrate was acquired from day 21 until day 30 of the wastewater experiment. The treatment with PSB showcased the bacteria's ability to utilize and absorb nutrients, thereby maintaining and improving water quality. The potential use of beneficial bacteria in the culture system can accelerate the nitrogen cycle for a sustainable way of wastewater management.

Determine the Essential Micronutrients Intake by Vibrio cholerae in Association with Algae in Different Waters

Phosphate, nitrite, nitrate are the micronutrients for Vibrio cholerae and algal growth. Current study intended to determine the utilization of these micronutrients by V. cholerae in association with algae in four different water (Distilled water, River water, Aritificial sea water and BOD dilution water). Amount of these micronutrients were estimated from stock water, control water and algal water by developing standard curve method. Among these four stock water, orthophosphate was the highest in amount (10.44µg/L) in BOD dilution stock water and significant positive changes (0.06 µg/L) from stock found in the algal water in River water microcosm. In stock sample , the highest amount of nitrite was found in both River and BOD dilution water (6.486µg/L) and the most significant increase ( 388.014µg/L) from stock was found in the control water of BOD dilution water. River stock water contained the maximum nitrate (1865.204µg/L) among four water types and the highest increase was found in the control water of River. In brief, the amount of phosphate, nitrite and nitrate varied with the types of water. Most cases amount of nitrite- nitrate increased by the decay of V. cholerae which used by algae for their growth and overloaded algae did not use phosphate from the surrounding water.

Improving the technology for the production of raw dried beef products

The relevance of this work lies in the need to reduce the negative impact on human health of sodium nitrite (food additive E250), which is added to meat products, in particular to raw dried sausages, in order to accelerate their maturation and give them the shades familiar to consumers. The aim of the work is to improve the technology for the production of raw dried beef products based on the use of modern biotechnological approaches, sea salt and the natural colouring agent betanin, and beetroot juice as a substitute for sodium nitrite. This goal was achieved through the implementation of a mixed salting method, whereby the surface of the meat semi-product was rubbed with a reduced amount of salt, including 0.0005 kilograms of sodium nitrite per kilogram of meat weight, compared to standard technology, and the rest of the salting mixture, which contained 0.0045 sodium nitrite, was injected deep into the semi-product as an aqueous solution. The source of nitrite was beetroot juice rich in nitrate ion, 0.03 dm3 of which contained 0.0052 kilograms of sodium nitrate, sufficient to synthesize 0.0045 kilograms of nitrite ion per kilogram of meat raw material. The chosen salting method reduced the amount of sodium nitrite from 0.015 to 0.005 kilograms per kilogram of meat product compared to the classical method, and the addition of beetroot juice made it possible to give the product a uniform colour throughout. Contamination of the product with dangerous microflora was prevented by adding a preparation containing bacteria of the Pediococcus acidilactici and Staphylococcus carnosus strains to the syringe solution. A positive effect of Pediococcus acidilactici was found, which was achieved by accelerating the pH of the meat mass to 5.0÷5.5, which stopped the growth of most dangerous microorganisms, including Shigella spp., Salmonella spp., Clostridium difficile and Escherichia coli. The product was protected from the development of Listeria monocytogenes bacteria by bacteria of the Staphylococcus carnosus strain. The proposed technology can be used in the food industry in the manufacture of raw meat products, which will significantly reduce the negative impact of sodium nitrite on human health

Theoretical estimation of nitrates and nitrites intake from food additives by the Brazilian population

Sodium and potassium nitrates and nitrites are preservatives widely used in meat products and some cheese. They are important toxicologically but there is a lack of data on the exposure of the Brazilian population to these additives. This study aimed to verify the frequency of the use of nitrates and nitrites in processed foods in Brazil and to estimate their theoretical intake by the Brazilian population. A database was built of supermarket products containing nitrates, nitrites, and antioxidants. The Theoretical Maximum Daily Intake (TMDI) and TMDI balanced by the prevalence of food consumption (TMDI BPFC) were determined using consumption data from the Household Budget Surveys (2008/2009 and 2017/2018). The TMDI for nitrates and nitrites was lower than the Acceptable Daily Intake (ADI) for all population groups. Considering the prevalence of food consumption (consumers only), the TMDI BPFC values were lower than the ADI for nitrates (between 0.4 and 0.9 times the ADI) but very high values were obtained for nitrites (between 10 and 24 times the ADI). Our results suggest that the Brazilian population, especially some population groups, may be consuming unsafe amounts of nitrite. As a consequence, their health may be at risk.

In situ generation of cold atmospheric plasma-activated mist and its biocidal activity against surrogate viruses for COVID-19.

To provide an alternative to ultra violet light and vapourized hydrogen peroxide to enhance decontamination of surfaces as part of the response to the COVID-19 pandemic. We developed an indirect method for in situ delivery of cold plasma and evaluated the anti-viral activity of plasma-activated mist (PAM) using bacteriophages phi6, MS2, and phiX174, surrogates for SARS-CoV-2. Exposure to ambient air atmospheric pressure derived PAM caused a 1.71 log10 PFU ml-1 reduction in phi6 titer within 5min and a 7.4 log10 PFU ml-1 reduction after 10min when the the PAM source was at 5 and 10cm. With MS2 and phiX174, a 3.1 and 1.26 log10 PFU ml-1 reduction was achieved, respectively, after 30min. The rate of killing was increased with longer exposure times but decreased when the PAM source was further away. Trace amounts of reactive species, hydrogen peroxide and nitrite were produced in the PAM, and the anti-viral activity was probably attributable to these and their secondary reactive species. PAM exhibits virucidal activity against surrogate viruses for COVID-19, which is time and distance from the plasma source dependent.

Study of Some Physiological Activities for Multimetal Tolerant Bacteria Under Metallic Stress

Electroplating effluents contain heavy metals besides nitrate, which can be harmful to aquatic and terrestrial life if released into the environment. Bioremediation is an imperative task to remove these contaminants from aquatic surfaces. Bacterial species that are tolerant to multiple metals were isolated from electroplating effluents and studied for their ability to withstand high metal concentrations and perform physiological activities. These activities included the production of carotenoid pigments and the reduction of nitrate during exponential and stationary growth phases after exposure to high concentrations of single and quaternary metals. The influence of heavy metals on these activities and bacterial behavior was evaluated. The results showed that the production of carotenoid pigments increased over time, with the highest quantities produced at 48 hours with Zn, Cu, and quaternary. Pigments produced vary with the different types of metals and their concentrations. The ratio of pigment extract to unladen metal cells was higher compared to laden metals cells. The isolates were also capable of reducing nitrate and producing nitrite, but high metal concentrations hindered the conversion of nitrite to nitrogen gas and accumulated great amounts of nitrite between the end of the exponential phase and the start of the stationary phase. The production of carotenoids allowed the bacteria to tolerate high metal concentrations and continue reducing nitrate. This study suggests that pigmented bacteria and aerobic denitrifiers have the potential for bioremediation and nitrate reduction, which can help clean and recover contaminated environments.

PHOSPHATE AND NITRITE - THE MOST COMMONLY USED ADDITIVES IN THE MEAT INDUSTRY

Food additive is any substance that, regardless of its nutritional value, is not used as food, nor is a characteristic ingredient of food, but is added to food for technological reasons during production, processing, preparation, packaging, transport or storage. Thus, through its intermediate products, it becomes or can become a food ingredient. The most commonly used additives are nitrites and phosphates, due to their multiple role in the meat industry. According to the Regulation on food additives (Official Gazette of the Republic of Srpska, 96/20), the maximum accepted amount of phosphoric acid and phosphate (E 338 - E 452), which can be added to meat products individually or in combination (expressed as P2O5), is 5 g/kg. Many studies have confirmed the connection between a high intake of phosphate additives and various diseases in humans. Nitrites are preservatives that are added to meat products in order to improve the quality, durability and safety of the products, and they must not be added in an amount higher than 150 mg/kg in most meat products. Due to the possibility, under certain conditions, of the formation of carcinogenic nitrosamines in meat products, there is a potential danger to human health. The aim of the study was to determine the content of residual nitrite and added phosphates (expressed as phosphorus pentoxide P2O5) in meat products originating from the market of Republika Srpska (Bosnia and Herzegovina) and compliance with regulatory requirements. The results showed that the determined amounts of residual nitrite and added phosphates were within the acceptable limits for addition to different categories and types of meat products according to current regulations. This confirms that the application of nitrite and phosphate is adequate and that the product is healthy. In order to protect the health of consumers, it is important to continuously monitor the use of phosphates and nitrites in the meat industry.

Experimental study on three additives used for the removal of nitrite, a byproduct of ozone oxidation denitration technology

Nitrogen oxides resulting from fossil fuel combustion are one of the major atmospheric pollutants. Ozone oxidation flue gas denitration technology has garnered significant attention for its benefits such as high efficiency, low temperature and simultaneous removal of multiple pollutants. However, the large amount of nitrite in the absorption products makes it prone to secondary pollution. A cost-effective and harmless treatment of the by-product nitrite will promote the ozone oxidation denitration technology. This study focused on investigating three different additives (ammonium chloride, ammonium carbonate, and urea) that can be added to react with nitrite and remove it in a harmless way. The effects of reaction temperature, initial nitrite ion concentration, reaction molar ratio, and initial pH on nitrite removal efficiency were explored. Combined with a wet spraying system, the synergistic removal of NOx/SO2 and by-product nitrite has also been studied. The experimental results revealed that with appropriate operating conditions and additives, the by-product nitrite can be efficiently removed while the system can achieve efficient removal of NOx/SO2. Among the three additives, ammonium carbonate was found to have the best overall removal effect. However, urea had an advantage over the other two additives in highly acidic and low-temperature slurry.