Search

The hazardousness of solvents used in synthetic organic chemistry is well established. In this context, it is relevant to search for safer and greener alternatives. Within the last decades, deep eutectic solvents have been considered as possible and promising alternatives. Consequently, this study aims at using deep eutectic solvents to synthesize an emerging class of heteroaromatic compounds named thiazolo[5,4-d]thiazoles, for which interest is growing in the field of organics, electronics, and biology. To address this challenge, we developed a straightforward synthetic protocol consisting of condensing dithiooxamide and aromatic aldehyde in deep eutectic solvents to yield the desired thiazolo[5,4-d]thiazole without further purification. The first hit was obtained with the well-known L-proline:glycerol (1:2) mixture at 130 °C. However, dithiooxamide is degraded under these conditions, leading to the formation of impurities that may arise from the consequent amount of reactive L-proline. Reaction conditions were optimized by modifying the deep eutectic solvent nature and proportions, applying various temperatures, changing the activation and heating source, or adding auxiliary oxidants. As a consequence, eight thiazolo[5,4-d]thiazoles were synthesized in equal or better yields (20 to 75%) than the reported procedure under safe and eco-friendly conditions in a mixture of L-proline and ethylene glycol (1:50) with sodium metabisulfite at 130 °C for one hour. [ABSTRACT FROM AUTHOR]

Background: This study investigates the potential effect of sub-chronic exposure to sodium metabisulfite (NaMBS) on the hippocampus and prefrontal cortex of female Wistar rats. Methods: A total of 24 adolescent female Wistar rats were randomly divided into four groups (6 rats each) as follows: Group 1 (control) received 0.5 mL of normal saline; group 2 was administered by 100 mg/kg of NaMBS; group 3 was issued by 300 mg/kg of NaMBS; group 4 received 500 mg/kg of NaMBS. The route of administration was oral for 28 days. After completing the administration phase, the Y-maze test was conducted. Subsequently, the rats were euthanized, and tissue samples from the prefrontal cortex and hippocampus were collected for biochemical assays, precisely measuring malondialdehyde (MDA) and acetylcholinesterase (AChE) levels, as well as histological studies, such as hematoxylin and eosin, and glial fibrillary acidic protein (GFAP). Meanwhile, the neuronal count was done. Results: The learning and memory functions of rats in the treated and control groups were similar (number of alternations: P>0.05). The group treated with 500 mg/kg NaMBS presented indications of neurodegeneration in CA1 of the hippocampus and high glial fibrillary acidic protein-immunoreactivity but had no noticeable effects on layer II/III of the prefrontal cortex. Regardless of the dosage of NaMBS, malondialdehyde level was the same (P>0.05) for all groups; however, in the group that received 500 mg/kg NaMBS, the acetylcholinesterase level was significantly reduced (P˂0.05). Conclusion: This study revealed that while NaMBS can lead to neurodegeneration in the hippocampus of Wistar rats at 500 mg/kg, the prefrontal cortex remains resilient and spatial memory is unaffected, but a decrease in acetylcholinesterase activity raises cognitive concerns, emphasizing the need for cautious consideration of its use.

Antarctic krill (Euphausia superba) is a vital species in the Antarctic ecosystem, boasting substantial reserves and high nutritional value. It has emerged as a significant commercial fishery resource in the Southern Ocean. However, because of its exceptionally high autolytic enzyme activity, it is susceptible to autolysis and blackening during processing, storage, and transportation, resulting in a decline in the sensory quality and nutritional value of raw materials. Shrimp melanosis is caused by a series of enzymatic reactions mediated by phenoloxidase (PO) within the body. PO facilitates the oxidation of phenolic substances, leading to the formation of highly unstable quinone compounds, which further react to produce melanin. The accumulation of melanin significantly affects the appearance of Antarctic krill, thereby reducing its commercial value. On account of their cost-effectiveness and potent anti-blackening effects, sulfites are commonly used as shrimp anti-black agents. Sodium metabisulfite is one of the compounds whose use is allowed for shrimp preservation under GB 2760-2014 regulations. It not only inhibits PO activity, but also reduces quinone compounds to prevent blackening. However, excessive sulfite use can lead to discomfort and health issues such as gastrointestinal problems, liver disturbances, dyspnea, vomiting, diarrhea, and headaches. Therefore, GB 2760-2014 regulations stipulate that the residual SO2 content should not exceed 0.1 g/kg. Currently, the use of sodium metabisulfite in production is widespread but lacks standardized requirements, with limited guidance available on how to regulate its usage. Therefore, to assess the impact of sodium metabisulfite on blackening control in Antarctic krill and refine the treatment process, experiments were conducted to measure the changes in SO2 residue and PO activity in Antarctic krill subjected to various concentrations of sodium metabisulfite solutions and soaking times. Furthermore, observations and analyses were conducted to monitor the blackening of Antarctic krill during cold storage and frozen storage. The results demonstrated a positive correlation between the SO2 residue in Antarctic krill and the concentration of sodium metabisulfite solution. A concentration of 1 g/L sodium metabisulfite solution resulted in a SO2 residue of 0.065 g/kg in Antarctic krill, which is below the national standard limit of 0.1 g/kg. However, treatment with a 2 g/L solution led to a SO2 residue of 0.166 g/kg in shrimp, exceeding the national standard limit. Treatment with a 3 g/L solution resulted in a SO2 residue of 0.254 g/kg in shrimp, which significantly surpassed the national standard limit. Consequently, we recommended using 1 g/L or 2 g/L sodium metabisulfite solutions to prevent blackening in Antarctic krill while maintaining the SO2 residue below 0.1 g/kg. Under these conditions, the treatment time for a 1 g/L sodium pyrosulfite solution could be extended to 300 s, with a relative PO activity of 21.2%. For a 2.0 g/L sodium pyrosulfite solution, a treatment time of 30 s was suitable, yielding a relative PO activity of 34.5%. During storage, the control group exhibited noticeable blackening after storage at 4 ℃ for 24 h and frozen storage for 6 months, predominantly in the head, chest, abdomen, and tail sections, and slight variations were observed in the blackening process among individuals. Compared with the control group, the sodium metabisulfite treatment group displayed significantly lower blackening scores during storage (P < 0.05). Specifically, the 1 g/L sodium metabisulfite solution with 300 s treatment group and the 2 g/L sodium metabisulfite solution with 30 s treatment group showed obvious blackening at 48 h and 72 h of cold storage, respectively, and after 12 months of frozen storage, indicating that higher concentrations of sodium metabisulfite solution during treatment led to a better control effect on the blackening of Antarctic krill during storage. Notably, PO activity is just one of the factors influencing the melanosis process. Although the 1 g/L sodium metabisulfite solution with treatment for 300 s could better inhibit PO activity, the anti-blackening effect of this group was not as pronounced as that of the 2 g/L sodium metabisulfite solution with treatment for 30 s during storage. In summary, soaking in 1 g/L sodium metabisulfite solution for 300 s and 2 g/L sodium metabisulfite solution for 30 s resulted in relative PO enzyme activities of 21.2% and 34.5%, respectively. Simultaneously, the SO2 residues in shrimp were measured at 0.094 g/kg and 0.096 g/kg, respectively, meeting the GB 2760-2014 limit of SO2 residue not exceeding 0.1 g/kg. Compared with the control group, sodium metabisulfite treatment effectively delayed the blackening process of Antarctic krill during cold storage and frozen storage, with the 2 g/L sodium metabisulfite solution soaking for 30 s exhibiting superior anti-blackening effects. This suggests that a high concentration of sodium metabisulfite solution and a short treatment period had a better blackening inhibition effect. These findings offer a theoretical foundation and technical guidance for maintaining the quality of Antarctic krill during storage and transportation.

We report an unprecedented synthesis of bis(pyrazolo[1,5- a ]pyrimidin-3-yl)methanes, a new class of di(hetaryl)methanes, from pyrazolo[1,5- a ]pyrimidines by using DMSO as a C1 synthon (methylene source). The transformation is mediated by sodium metabisulfite (Na2 S2 O5), which plays a crucial role in the presence of acetic acid as a promoter. A wide variety of bis(pyrazolo[1,5- a ]pyrimidin-3-yl)methanes were synthesized in moderate to good yields of up to 90%. Mechanistic studies suggested that the reaction follows an ionic pathway, probably involving a methyl(methylene)sulfonium ion as an active electrophilic species formed in situ by the reaction of DMSO with Na2 S2 O5. [ABSTRACT FROM AUTHOR]

Young coconuts (Cocos nucifera L.) used for export are trimmed to reduce their size and weight to lower transport costs. However, trimmed coconuts have a shorter shelf life due to microbial spoilage and surface discoloration caused by enzymatic browning. To minimize these effects, trimmed coconuts were dipped in an anti-browning agent, sodium metabisulfite (SMB), and stored under ambient conditions. However, there have been no reports on the effects of SMB treatment on metabolome changes in the flesh and water of young coconuts. Hence, this study investigated the metabolite changes in trimmed young coconuts after SMB treatment under different storage conditions using a gas chromatography (GC)/mass spectrometry (MS) metabolomic profiling approach. Tall young coconut samples were trimmed and treated with a 2% SMB solution for 5 min before storage at 25 °C or 4 °C for 2–4 weeks. Coconut flesh and water samples were collected after storage for 0, 2, and 4 weeks, and were subjected to GC–MS analysis. The results showed that the major metabolites affected by coconut deterioration were amino acids, sugars, and sugar alcohols. SMB treatment and/or refrigeration can help prevent metabolite changes in the flesh and water of young coconuts. In the future, improvements in storage conditions based on metabolite profiles should be explored. [Display omitted] [ABSTRACT FROM AUTHOR]

Herein, we report a simple and an economical method to synthesize C‐substituted bis‐benzimidazole and C‐substituted benzobisimidazole derivatives in moderate to excellent yields using sodium metabisulfite, under microwave irradiation conditions. The most attractive feature of the methodology is the three‐step yet one‐pot condensation of nitroarenes with various benzaldehyde derivatives to synthesize useful benzimidazoles, and an easy product isolation method by simple solvent trituration techniques. The methodology can be fine‐tuned to synthesize selectively the mono C‐substituted benzimidazoles, leaving a nitroaniline functionality intact for preparing a variety of unsymmetrical C‐substituted bis‐benzimidazoles. [ABSTRACT FROM AUTHOR]

Pyrite has natural floatability and thus readily enters valuable mineral flotation concentrates, diluting their quality and decreasing their economic value. Its separation is challenging, depending on process conditions, the presence of activating ions, and water quality, particularly in regions where seawater is used. This study examines the effect of various doses of sodium metabisulfite (SMBS) on pyrite depression in freshwater and seawater under weakly alkaline conditions and with different copper ion concentrations. Without the addition of activators or depressants, pyrite recovery is 40% in freshwater and 60% in seawater, whereas with 10 ppm of SMBS, recoveries drop to 28% and 38%, respectively. The addition of 10 ppm Cu2+ increases recovery by 10% in freshwater and by 20% in seawater. In the presence of 75 ppm of PAX, maximum recovery reached 50% in freshwater and 80% in seawater. These results suggest that cationic bridges formed by seawater ions, combined with CaOH+ activation, play a critical role in pyrite activation, even in the presence of depressants. [ABSTRACT FROM AUTHOR]

Chayote is a vegetable that can be processed into various kinds of dishes. If you peel chayote, it will leave a sticky sap on your hands that is not easy to remove even if you wash it repeatedly with soap. Rumah Sayur Cisarua, Bandung Barat markets cut peeled chayote products. Cut peeled chayote quickly experiences a decline in quality, characterized by the color changing to brownish (enzymatic browning). For this reason, research was carried out with the aim of obtaining a minimally process design for cut peeled chayote. The treatment design tested was chemical treatment, by immersion in citric acid solution (0.5; 1.0; 1.5%) and sodium metabisulfite solution (500, 750, 1000 ppm), physical treatment by blanching (10, 20, 30 seconds ), as well as a combination of chemical and physical treatments. The minimally process design chosen was soaking in 500 ppm sodium metabisulfite for 15 minutes and sulfite residue was not detected. Cut peeled chayote with this treatment remains fresh until the fourth day of storage.

BACKGROUND: High moisture meat analog (HMMA) products processed using extrusion have become increasingly popular in the last few years. Because the formation of disulfide bonds is believed to play a critical role in the texturization mechanism, this study aimed to understand how chemical compounds capable of reducing disulfide bonds, specifically cysteine, sodium metabisulfite, and glutathione, affect the texture and the chemical interactions between the proteins. METHOD: Wheat protein blended with cysteine, sodium metabisulfite, or glutathione at levels of 0, 0.5, 1.0, 2.5, 5.0, and 7.5 g kg−1 was extruded at three different temperatures (115, 140, and 165 °C) using a co‐rotating twin‐screw extruder. The feed rate (85 g min−1), the moisture content (600 g kg−1), and the screw speed (300 rpm) were kept constant. Unextruded and extruded material was subjected to sodium dodecyl sulfate‐polyacrylamide gel electrophoresis, polymeric protein fractionation, and sulfhydryl group/disulfide bond analysis. Extruded samples were further analyzed for their hardness and their anisotropic index. RESULTS: The inclusion of reductants significantly affected the structure of the obtained extrudates. Although reducing agents had a relatively small impact on the total amount of disulfide bonds, their action significantly enhanced crosslinking between the proteins. At select conditions, samples with high fibrousness were specifically obtained when cysteine or sodium metabisulfite was included at levels of 5.0 g kg−1. DISCUSSION: In the presence of reducing agents, it is believed that disulfide bonds are split earlier during the process without binding to them, giving the protein strands more time to unravel and align, leading to a better flow behavior and more fibrous products. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

An incision wound is a wound caused by being sliced. Two ingredients that play a key role in the wound-healing process are glucomannan and acemannan, which are rich in polysaccharides and growth hormones. Growth hormones stimulate fibroblast activity and proliferation. The present study involved 35 Sprague Dawley male rats, aged 2-3 months old and weighing 200-300 grams. The study comprised seven groups including, negative control group (G1), positive control (aquades, G2), betadine 10% (G3), gel base (0.5 mg, G4), gel base + sodium metabisulfite 0.2 gr (G5), gel base + Aloe vera 5% (G6), and gel base + Aloe vera 5% + sodium metabisulfite 0.2 gr (G7). Each group had five replications. Initially, a 4-cm incision was made on the dorsal skin of each rat. The study lasted 15 days with observations made on days 3, 7, and 15. After the observation period, the rats were anesthetized and then terminated to collect skin tissues for microscopic examination. The tissue samples were then stained immunohistochemically to assess fibroblast growth factor (FGF) expressions. The results showed that the highest FGF expression was observed in the 5% Aloe vera + 2% metabisulfite group (G7), while the lowest FGF expression was in the negative control group (G1). It is concluded that Aloe vera L. extract gel at 5% + 2% metabisulfite (G7) significantly enhances the expression of FGF. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agroindustrial Technology / Jurnal Teknologi Industri Pertanian is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aimed to investigate the effect of zinc oxide nanoparticles in combination with a composite (gelatin/alginate) on the shelf life of white leg shrimp (Litopenaeus vannamei) during 10 days of refrigerated storage. Shrimp were prepared in 5 treatments, including: control (shrimp treated in distilled water), SMS (shrimp treated with sodium metabisulfite solution), composite (shrimp treated in an alginate/gelatin coating), ZnO2.5 [shrimp treated in a composite containing 2.5% ZnO nanoparticles (w/w)], and ZnO5 [shrimp treated in a composite containing 5% ZnO nanoparticles (w/w)]. The results showed that the number of mesophilic aerobic bacteria, Pseudomonas, and lactic acid bacteria in the control sample increased significantly until the end of the storage period, while the samples containing ZnO nanoparticles had significantly lower levels of bacteria. In addition, total volatile base nitrogen, trimethylamine, thiobarbituric acid species, and pH levels in shrimp treated with the nanoparticles were significantly lower than those in the control group (P < 0.05). The highest and lowest changes in texture (springiness and cohesiveness) were observed in the control and treatments containing ZnO, respectively (P < 0.05). The sensory evaluation, texture, and color results were consistent with those of other reported data. However, using an alginate/gelatin coating significantly delays shrimp spoilage during refrigerated storage, and the use of zinc oxide nanoparticles significantly reduces microbiological and chemical spoilage and increases the shelf life of shrimp. [ABSTRACT FROM AUTHOR]

Background and Objectives: Pulse flours are gaining popularity in baked goods, but their use is limited due to strong flavors. This study analyzed the addition of pea flour to pancakes, with and without sodium metabisulfite (SMB), to assess their impact on pancake quality and reduce off‐flavors. Findings: Because pancake formulations were standardized based on batter viscosity, only at 20% pea flour incorporation did changes to pancake physical quality occur. Adding pea flour to pancakes impacted sensory aspects such as cooked pea flavor, nutty flavor, and pea odor. In combination with SMB, pea flour can be added up to 5% without imparting significant cooked pea flavor to pancakes. SMB also reduced pea odor in pancakes with 1%–5% pea flour. Conclusions: Pea flour can be added to pancakes without significantly affecting physical quality, as long as the batter viscosity is optimized. SMB can have a positive effect on limiting off‐flavors in pancakes containing pea flour. This research provides valuable insights into the effects of substituting pea flour in soft wheat batter‐based bake systems. Significance and Novelty: Pancakes with up to 20% pea flour had similar physical characteristics to wheat pancakes. Pea flavors were detectible at 5% inclusion, and SMB reduced off‐flavor perception at low pea flour inclusion rates. [ABSTRACT FROM AUTHOR]

Acanthamoeba keratitis (AK) is a severe infection of the cornea. Prevention and treatment are difficult due to the inefficacy of currently available compounds. The impact of many commonly used compounds for routine examinations of Acanthamoeba is unexplored but might offer insight useful in combatting AK. In this study, we demonstrate that sodium metabisulfite, a common preservation constituent of eye care solutions, was found to be active against Acanthamoeba trophozoites at concentrations lower than that commonly found in eye drops (IC50 0.03 mg/mL). We demonstrate that sodium metabisulfite depletes thiamine from growth medium and that Acanthamoeba is a thiamine auxotroph, requiring thiamine salvage for growth. The inhibitory effects of sodium metabisulfite can be overcome by thiamine supplementation. These results are consistent with the lack of key enzymes for thiamine biosynthesis in the genome of Acanthamoeba, an area which might prove exploitable using new or existing compounds. Indeed, this study highlights sodium metabisulfite as a useful inhibitor of Acanthamoeba castellanii trophozoites in vitro and that it acts, at least in part, by limiting available thiamine. [ABSTRACT FROM AUTHOR]

This study evaluates the efficacy of the salts sodium metabisulfite (SMB), ammonium bicarbonate, sodium bicarbonate, and potassium dihydrogen orthophosphate first in vitro against the main postharvest fruit rot fungi, Alternaria alternata, Botrytis cinerea, Penicillium italicum, and Penicillium digitatum. Results showed that 0.2% SMB completely inhibited the mycelium growth of the fungal species. Ammonium bicarbonate and sodium bicarbonate were less effective at 0.2% in inhibiting mycelial growth, ranging from 57.6% to 77.6%. The least effective was potassium dihydrogen orthophosphate. Experiments were also performed in vivo on wounded apples inoculated with the most pathogenic fungus, B. cinerea, and treated with SMB at concentrations of 0.2, 0.5, 1, 2, and 3%, both preventively and curatively. Results based on the decay size showed that SMB, when used as a preventive treatment, had a reduced efficacy, even with the highest concentration. However, this salt proved to be very effective at 0.5% in curative treatment since the decay was completely blocked. Our results suggest that the appropriate concentration of SMB for post-harvest treatment is 0.5% as a curative treatment. On the other hand, the 1% dose induced the onset of phytotoxicity around the wound. To assess the extent of the phytotoxicity reaction, higher concentrations of 1–4% SMB were applied to wounded fruit. Apples and oranges were inoculated or not with B. cinerea and P. digitatum, respectively. Doses of 1–4% induced phytotoxicity in the form of a discolored ring surrounding the wound on the epidermis of the fruit; this phytotoxicity enlarged as the concentration of SMB increased. The phytotoxic features were similar on apples and oranges. The methodological procedure made it possible to carry out a quantitative assessment of SMB phytotoxicity. This method is proposed as an easy-to-use technique for quantitatively estimating the phytotoxicity of antifungal compounds on post-harvest fruit. [ABSTRACT FROM AUTHOR]

Houttuynia Cordata (HC) is a widely distributed plant in Asia and is used extensively for both food and medicinal purposes. A preliminary investigation found that HC is often bleached with sodium metabisulfite solution during its field processing, leading to health risks. In this study, the effects of sodium metabisulfite on the quality of HC were comprehensively evaluated using volatile and non-volatile targeted metabolomic methods. The results revealed a positive correlation between the extent of chemical composition changes and the bleaching time. These notable changes mainly occurred at the initial stage of bleaching. Subsequently, an untargeted UPLC/Q-TOF MS method was used to explore the potential chemical bleaching markers in bleached HC. The marker 1-hydroxy-3-oxodecane-1-sulfonic acid was subsequently prepared, isolated, and identified. Market sample verification further validated the accuracy and effectiveness of this marker.

Porang (Amorphophallus muelleri) is a type of tuber that has a high glucomannan content. The purpose of this study was to determine the effect of slice thickness on the quality of porang tuber chips using the Green House Effect (GHE) method by pretreatment with 0.15% sodium metabisulfite solution immersion. The slice thickness treatment was carried out at three levels, including 4 mm, 6 mm, and 8 mm, while the drying treatment was carried out with two types, which are the GHE drying method and the conventional drying method using sunlight. The results of the research on porang chips on brightness, moisture content, glucomannan content, ash content, and calcium oxalate content showed that the thickness of the slices had an effect on the quality of the chips. The thicker the slices of the porang chips, the darker the color of the porang chips. The thicker the slices of the porang chips, the higher the water content of the chips. The amount of glucomannan (%) in porang chips goes down as the slices get bigger.

Background: Sodium metabisulfite (Na2S2O5) is a disinfectant and preservative agent which is commonly used in food industry and polluted water bodies through industrial wastes. Objective: Current study was conducted to observe the impact of widely used salt on the gills, kidney and liver of Labeo rohita. Methods: Fish were divided into three groups. One group treated as control. Two groups were exposed to sodium metabisulfite in different concentrations (29 mg/L and 68 mg/L) for 28 days. Results: The 96h LC50 value for sodium metabisulfite (Na2S2O5) was found to be 130 mg/L. Histological changes revealed moderate to severe damage in time and concentration dependent manners. Photomicrograph of gills of exposed fish showed different histological alterations such as hyperplasia, marginal gill lamellae, blood congestion, gills lamellae aneurysm and distortion of the gill cells. Results indicated that exposure to sodium metabisulfite caused severe progressive alterations such as melanomacrophage, cytoplasmic vacuolization, hepatocytes and cluster nuclei in liver tissues of exposed fish. Kidney tissues of treated L. rohita revealed different histological changes including, wide hypertrophied nucleus, sinusoidal spaces, cloudy swelling degeneration, glomerular expansion and tubules starting the degeneration process as compared with control fish. Conclusion: Our results represent the pioneering report demonstrating that sodium metabisulfite can act as a potent toxic agent for Labeo rohita.

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: The role of contact sensitisation in the pathogenesis of oral lichen planus (OLP) has not been clearly defined. Objective: We aimed to evaluate relevant contact sensitisers in OLP. Methods: A retrospective study was conducted on OLP patients who underwent patch testing from 1 January 2006 to 31 December 2020 at an Australian tertiary dermatology institution, compared to cheilitis patients patch tested over the same time period. Results: Ninety‐six OLP patients and 152 cheilitis patients were patch tested during the 15‐year period. Seventy‐one (73.9%) OLP patients and 100 (65.8%) cheilitis patients recorded one or more relevant reactions. Forty‐three (44.8%), 22 (22.9%), 21 (21.9%) and 17 (17.7%) OLP patients had relevant reactions to mercury‐related chemicals, amalgam, spearmint and carvone, respectively, compared to 6 (3.9%), 3 (2.0%), 4 (2.6%) and 0 (0%) cheilitis patients, respectively (p‐value <0.001 each). Four (4.2%) OLP patients had relevant positive reactions to sodium metabisulfite, compared to none in the cheilitis group (p‐value 0.021). Conclusion: While dental amalgam is used less frequently these days, we report that mercury (found in amalgam) and additionally spearmint and carvone are relevant sensitisers in OLP in Australia. Sodium metabisulfite may also be a relevant sensitiser in OLP, which has not previously been reported. [ABSTRACT FROM AUTHOR]

Female pigs respond sensitive both to DON and ZEN with anorexia and endocrine disruption, respectively, when critical diet concentrations are exceeded. Therefore, the frequent co-contamination of feed by DON and ZEN requires their parallel inactivation. The additive ZenA hydrolyzes ZEN while SBS inactivates DON through sulfonation. Both supplements were simultaneously added (+, 2.5 g SBS and 100 U ZenA/kg) to a control diet (CON−, 0.04 mg DON and < 0.004 mg ZEN/kg; CON+, 0.03 mg DON and < 0.004 mg ZEN/kg) and a Fusarium toxin contaminated diet (FUS−, 2.57 mg DON and 0.24 mg ZEN/kg; FUS+, 2.04 mg DON and 0.24 mg ZEN/kg). The 4 diets were fed to 20 female weaned piglets each (6 kg initial body weight) for 35 days; the piglets were sacrificed thereafter for collecting samples. Supplements improved performance and modified metabolism and hematology independent of dietary DON contamination. The mechanisms behind these changes could not be clarified and require further consideration. SBS reduced DON concentration in feed by approximately 20% and to the same extent in blood plasma and urine suggesting that no further DON sulfonate formation occurred in the digestive tract before absorbing DON in the upper digestive tract or that additionally formed DON sulfonates escaped absorption. DON sulfonates were detected in feces suggesting that unabsorbed DON sulfonates reached feces and/or that unabsorbed DON was sulfonated in the hindgut. The observed reduction rate of 20% was evaluated to be insufficient for feeding practice. Galenic form of SBS added to dry feed needs to be improved to support the DON sulfonation in the proximal digestive tract.ZenA was active in the digestive tract as demonstrated by the presence of its hydrolyzed none-estrogenic reaction products hydrolyzed ZEN (HZEN) and decarboxylated and hydrolyzed ZEN (DHZEN) both in feces, systemic circulation, and urine of group FUS+ compared to group FUS−. The presence of these hydrolysis products was paralleled by a significant decrease in high-estrogenic ZEN concentrations which, in turn, was related to a decrease in relative weights of uteri and ovaries when compared to group FUS−. Thus, ZenA was proven to be effective; both in terms of biomarkers and biological effects. [ABSTRACT FROM AUTHOR]

This study aimed to improve the color removal of talodora syrup by using sodium metabisulfite and ammonium persulphate, which have a very important effect in the bleaching process. The behavior of the materials used at different concentrations on Brix and the pH of the syrup was studied, as well as the color removal efficiency. Experiments were carried out at Hawamdia sugar refinery factory, Giza Governorate, in the General Administration for Quality and Control, during September and October 2022. The results showed that the rate of decolorization of the samples increased with the increase the concentration of the additives. The best color removal of the syrup is 60.4% when using Sodium metabisulfite at a concentration of 550 ppm on the processed syrup. While the best color removal of the syrup was 35.2% when ammonium persulphate at a concentration of 800 ppm was added to outlet syrup of talodora when compared to color of outlet syrup of talodora. On the other hand, it became clear that the removal color of the syrup when adding the material at the same concentration to the treated syrup was 70.2%, when compared to the color of the syrup inlet talodora. Through the results obtained, it was clear that ammonium persulfate was better than sodium meta sulfite of its effect on removing the color of syrup. [ABSTRACT FROM AUTHOR]

Acanthamoeba keratitis (AK) is a severe infection of the cornea. Prevention and treatment are difficult due to the inefficacy of currently available compounds. The impact of many commonly used compounds for routine examinations of Acanthamoeba is unexplored but might offer insight useful in combatting AK. In this study, we demonstrate that sodium metabisulfite, a common preservation constituent of eye care solutions, was found to be active against Acanthamoeba trophozoites at concentrations lower than that commonly found in eye drops (IC50 0.03 mg/mL). We demonstrate that sodium metabisulfite depletes thiamine from growth medium and that Acanthamoeba is a thiamine auxotroph, requiring thiamine salvage for growth. The inhibitory effects of sodium metabisulfite can be overcome by thiamine supplementation. These results are consistent with the lack of key enzymes for thiamine biosynthesis in the genome of Acanthamoeba, an area which might prove exploitable using new or existing compounds. Indeed, this study highlights sodium metabisulfite as a useful inhibitor of Acanthamoeba castellanii trophozoites in vitro and that it acts, at least in part, by limiting available thiamine.

This article presents a case report of a 59-year-old male who experienced recurrent rashes on the flexor sides of his knees, elbows, axillae, and groin. The rash, known as Symmetric Drug-related Intertriginous and Flexural Exanthema (SDRIFE), occurred after exposure to local anesthesia containing sodium metabisulfite. Patch testing confirmed a positive reaction to sodium metabisulfite, which is a preservative found in anesthesia solutions. The patient was advised to avoid local anesthetics with sodium metabisulfite, but could still receive adrenaline in case of a severe allergic reaction. Treatment for SDRIFE involves discontinuing the use of offending agents and may include antihistamines and glucocorticosteroids for symptomatic relief. [Extracted from the article]

In order to prompt the appearance of the shrimp color, sodium metabisulfite is frequently added in shrimp processing, which is, however, prohibited in China and many other countries. This study aimed to establish a surface-enhanced Raman spectroscopy (SERS) method for screening sodium metabisulfite residues on shrimp surfaces, in a non-destructive manner. The analysis was carried out using a portable Raman spectrometer jointly with copy paper loaded with silver nanoparticles as the substrate material. The SERS response of sodium metabisulfite gives two fingerprint peaks at 620 (strong) and 927 (medium) cm−1, respectively. This enabled unambiguous confirmation of the targeted chemical. The sensitivity of the SERS detection method was determined to be 0.1 mg/mL, which was equal to residual sodium metabisulfite on the shrimp surface at 0.31 mg/kg. The quantitative relationship between the 620 cm−1 peak intensities and the concentrations of sodium metabisulfite was established. The linear fitting equation was y = 2375x + 8714 with R2 = 0.985. Reaching an ideal balance in simplicity, sensitivity, and selectivity, this study demonstrates that the proposed method is ideally suitable for in-site and non-destructive screening of sodium metabisulfite residues in seafood. [ABSTRACT FROM AUTHOR]

Objectives The objective of this study was to find a promising dechlorination chemical which can replace sodium bisulfite (SBS), which is mainly used as a dechlorination agent in reverse osmosis processes but can cause odor issues. Methods Candidate chemicals were selected in consideration of economic feasibility, ease of use, and toxicity. These included sodium metabisulfite (SM), sodium thiosulfate (ST), and sodium sulfite (SS). We investigated the effect of organic matters in water on residual chlorine decomposition and compared the appropriate injection amounts for each dechlorination chemicals. Also, the effect of the pH of treated water upon dechlorination was assessed. Results and Discussion Upon injection of dechlorination chemicals at the theoretical chlorine removal point, the chlorine was not completely removed but 10% to 40% remained. In ultrapure water, it was possible to completely dechlorinate by injecting 1.6 to 2.6 times more than the theoretical injection amount: 1.8, 2.2, and 3.1 times more for ST, SM, and SS, respectively. Considering only the injection amount, ST is an efficient dechlorination chemical for water with pH 9 or higher, and SM is for pH 9 or less Conclusion Considering the product price and user convenience, it is feasible to use ST, which can resolve the odor problem.

The Asteraceae are the largest plant family but among the least studied at the genome level. Our work investigated practical methods to reduce the influence of secondary metabolites – specifically, phenolic compounds – on the extraction of DNA from Silphium spp. This genus is in the Heliantheae tribe of Asteraceae that also includes sunflower (Helianthus annuus). Three methods were attempted in Silphium, with varying condition and age of the leaf sample. A modified cetyl trimethylammonium bromide (CTAB) method on young leaves resulted in the best DNA yield, with sufficient sample purity. No perceptible difference was observed between fresh and lyophilized samples for any extraction method or leaf age. These results provide an excellent basis for DNA extraction of difficult plant samples.

This study aimed to investigate the effects of sodium metabisulfite (SMBS) and SMBS-containing hydrogenated palm oil (HS) microparticles on the growth performance and intestinal barrier functions of weanling piglets challenged by deoxynivalenol (DON)-contaminated diets. Four corn-soybeanmeal based diets were used: 1) negative control (NC, 0.00 mg/kg of DON); 2) positive control (PC, 3.3 mg/ kg of DON); 3) SMBS (PST, 3.3 mg/kg of DON and 0.2% of SMBS); and 4) HS microparticles (HST, 3.3 mg/kg of DON and 0.45% of HS microparticles). Weaned piglets (n = 40) with similar body weights (BW; 8.22 ± 0.39 kg, 10 pigs/treatment) were fed for 28 d, including a 1-wk adjustment and 3 wk for exposure. Piglets subjected to the PC diet exhibited a noteworthy reduction in final BW by 13.3%, average daily gain (ADG) by 21.4%, and average daily feed intake (ADFI) by 20.1% compared with those on the NC diet (P < 0.05). Compared with the PC diet, the PST and HST diets increased by 6.76% and 4.31% in final BW (P < 0.05), 13.6% and 8.60% in ADG (P < 0.05), and 9.15% and 9.71% in ADFI (P < 0.05), respectively. No significant differences were detected in these values between the NC, PST, and HST diets (P > 0.05). There were no significant variations observed in the feed conversion ratio (FCR) among the four dietary treatments (P > 0.05). Feeding the PC diet to piglets led to a significant increase in the fecal score compared with the NC and HST diets (P < 0.05). No significant differences were detected in the mRNA expression levels of nutrient transporters and tight junction proteins among these four diets (P > 0.05). Additionally, compared with the NC diet, the PC diet significantly increased the mRNA abundance of Interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α, and toll-like receptor 4 (TLR4; P < 0.05); however, a decreased mRNA abundance of IL-8 and TNF-α was observed in the pigs fed the HST diet (P < 0.05), indicating that the encapsulated SMBS from the HS microparticles could have the potential to mitigate the effects of DON. Overall, adding 0.45% of HS microparticles to a 3.3 mg/kg DON-contaminated diet in piglets could maintain the growth performance, and using the HS microparticles revealed some potential in DON detoxification by reducing the gene expressions of proinflammatory cytokines. [ABSTRACT FROM AUTHOR]

Sulfur dioxide–sulfites (E 220–228) were re‐evaluated in 2016, resulting in the setting of a temporary ADI of 0.7 mg SO2 equivalents/kg bw per day. Following a European Commission call for data, the present follow‐up opinion assesses data provided by interested business operators (IBOs) and additional evidence identified in the publicly available literature. No new biological or toxicological data addressing the data gaps described in the re‐evaluation were submitted by IBOs. Taking into account data identified from the literature search, the Panel concluded that there was no substantial reduction in the uncertainties previously identified in the re‐evaluation. Therefore, the Panel considered that the available toxicity database was inadequate to derive an ADI and withdrew the current temporary group acceptable daily intake (ADI). A margin of exposure (MOE) approach was considered appropriate to assess the risk for these food additives. A lower confidence limit of the benchmark dose of 38 mg SO2 equivalents/kg bw per day, which is lower than the previous reference point of 70 mg SO2 equivalents/kg bw per day, was estimated based on prolonged visual evoked potential latency. An assessment factor of 80 was applied for the assessment of the MoE. At the estimated dietary exposures, when using a refined exposure scenario (Data set D), MOEs at the maximum of 95th percentile ranges were below 80 for all population groups except for adolescents. The dietary exposures estimated using the maximum permitted levels would result in MOEs below 80 in all population groups at the maximum of the ranges of the mean, and for most of the population groups at both minimum and maximum of the ranges at the 95th percentile. The Panel concluded that this raises a safety concern for both dietary exposure scenarios. The Panel also performed a risk assessment for toxic elements present in sulfur dioxide–sulfites (E 220–228), based on data submitted by IBOs, and concluded that the maximum limits in the EU specifications for arsenic, lead and mercury should be lowered and a maximum limit for cadmium should be introduced. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The primary benefit of using sulfites as a food additive is their antimicrobial and antioxidant properties, which stop fungi and bacteria from growing in a variety of foods. The application of analytical methods is necessary to ensure food quality control related to the presence of sulfites in a variety of foods. For the detection of sodium metabisulfite in food and urine samples, two sensors based on reduced graphene oxide doped with Pd paste and modified with 5,10,15,20-tetraphenyl-21H,23H-porphyrin and 5,10,15,20-tetrakis (pentafluorophenyl chloride)-21H,23H-iron (III) porphyrin were proposed. The new sensors were evaluated and characterized using square wave voltammetry. The response characteristics showed that the detection limits for the sensors were 3.0 × 10−12 mol L−1 for TPP/rGO@Pd0 based sensors and 3.0 × 10−11 mol L−1 for Fe(TPFPP)Cl/rGO@Pd0 based sensors while the quantification limits were 1.0 × 10−11 mol L−1 for TPP/rGO@Pd0 based sensors and 1.0 × 10−10 mol L−1 for Fe(TPFPP)Cl/rGO@Pd0 based sensors. The sensors can be used to determine sodium metabisulfite in a concentration range between 1.0 × 10−11 and 1.0 × 10−7 mol L−1 for TPP/rGO@Pd0 based sensors and between 1.0 × 10−10 mol L−1 and 1.0 × 10−6 mol L−1 for Fe(TPFPP)Cl/rGO@Pd0 based sensors. A comparison between the proposed methods' results and other analytical applications is also presented. [ABSTRACT FROM AUTHOR]

Shrimp is a highly perishable product with limited shelf life due to melanosis and biological composition. Controlling the destructive effects of melanosis is one of the major challenges for the industry. Melanosis in crustaceans is usually controlled by inhibitors such as sodium metabisulfite. However, the use of synthetic inhibitors for melanosis and antioxidants in food processing is usually limited by considerations related to safety and impact on food quality. Thus, over the last decade, the trend towards studies on the use of natural extracts to control shrimp melanosis has increased. Data from some articles published by ScienceDirect, PubMed, Scopus, SpringerLink, and Scopus databases on the occurrence of melanin black pigment in shrimp skin were used. The shrimps were dipped in extracts and stored in ice or refrigerator. In Iran, only the effects of grape seed extract to prevent melanosis have been studied. Some studies have reported higher effects of plant extracts such as Garcinia cowa Roxb, Persicaria Odorata, rosemary, green tea, avocado, Arabic coffee grounds, and chamomile than sodium bisulfite. Some researchers have described the effects of extracts such as olive, rosemary, and thyme along with metabisulfite in preventing melanosis more than metabisulfite alone. Plant extracts were effective in reducing black spots in shrimp for 2-28 days. Studies have shown that plant extracts can act as antioxidants and be an effective natural alternative to inhibit melanosis after shrimp death.

Introduction: Using herbal essential oils and extracts as antibacterial agents has attracted great attention for preventing the growth of pathogenic bacteria. The present study aimed to compare the effects of sodium metabisulfite and Mentha longifolia L. essential oil (MEO; 0%, 0.5%, 1%, and 2%) in the growth prevention of Listeria monocytogenes and Escherichia coli O157:H7 in peeled giant freshwater prawns in cold storage for two weeks. Methods: The antimicrobial effects of MEO against L. monocytogenes and E. coli O157:H7 were investigated in-vitro using the disk diffusion method. In addition, the effects of the direct addition of MEO (0%, 0.5%, 1%, and 2%) and sodium metabisulfite (1.25%) to prawn samples were evaluated. Results: The major chemical constituents of MEO were pulegone (47.20%), eucalyptol (22.72%), and menthone (13.44%). The mean diameter of the inhibition zone of MEO against L. monocytogenes and E. coli O157:H7 was determined to be 9.45±0.23 and 6.37±0.02 millimeters, respectively. MEO concentrations of 0.5%, 1%, and 2% significantly reduced the growth of L. monocytogenes and E. coli O157:H7 compared to the control group (P

Peracetic acid (PAA) stands out as a safe and environmental-friendly oxidant and disinfectant which has been effectively used in wastewater treatment. Chemical oxygen demand (COD) is a very popular analysis in wastewater treatment; however, the interference of residual PAA on the COD measurement is still unknown. In this context, this study investigated the implications of applying the COD analysis in PAA-based treatment. Each 1 mg·L−1 of PAA increased the COD concentration around 13.5 mg O2·L−1. Residual PAA and hydrogen peroxide (H2O2) were efficiently neutralized by sodium metabisulfite (SMBS) at the optimal SMBS/PAA ratio of 10.2:1 in a wide pH range (5 to 9). The effect of PAA addition on the COD concentration was evaluated in different water matrices (potassium hydrogen phthalate and wastewater solutions). The COD results with the SMBS addition at optimal SMBS/PAA ratio were lower than the ones without it. It may happen due to the neutralization of residual H2O2/PAA and the complexity of the water matrices which can interfere in the COD results. This study discussed the impact of the residual H2O2/PAA neutralization before the COD analysis, and this investigation can be used as a practical guideline for the correct COD measurement in PAA-based treatment. HIGHLIGHTS Influence of peracetic acid (PAA) in COD test was analyzed.; Sodium metabisulfite (SMBS) was efficient in quenching the PAA.; Total neutralization by SMBS allowed a correct COD measurement.;

Myofibrillar protein (MP) gels are susceptible to oxidation, which can be prevented by complexing with hydrophilic polyphenols, but may cause gel deterioration. Sodium metabisulfite (Na 2 S 2 O 5) has been used to induce self-assembly of MP and analyze the impact of self-assembly on the quality of composite gels containing high amounts of (−)-epigallocatechin gallate (EGCG). Hydrophobic forces were confirmed as the main driver of self-assembly. Self-assembly reduced the size of the MP–EGCG complex to approximately 670 nm and increased the gel's hydrophobic force by approximately 3.6-fold. The maximum hardness of the Na 2 S 2 O 5 -treated MP–EGCG composite gel was 52.43 g/kg, which was approximately 49% greater than pure MP gel. After oxidative treatment, the Na 2 S 2 O 5 -treated MP–EGCG composite gel had considerably lower carbonyl and dityrosine levels (2.47-μmol/g protein and 450 a.u.) than the control (8.37-μmol/g protein and 964 a.u.). Therefore, Na 2 S 2 O 5 shows potential as a cost-effective additive for alleviating MP limitations in the food industry. • Sodium metabisulfite-induced self-assembly of myofibrillar protein (MP). • Self-assembled MP formed stronger gel via increased hydrophobic interactions. • Self-assembly reduced size of MP-epigallocatechin gallate (EGCG) complexes. • Composite gels of self-assembled MP-EGCG exhibited enhanced oxidative stability. [ABSTRACT FROM AUTHOR]

Background: In 2019, a number of allergens (haptens), henceforth, "the audit allergens," were considered as potential additions to the European Baseline Series (EBS), namely, sodium metabisulfite, 2‐bromo‐2‐nitropropane‐1,3‐diol, diazolidinyl urea, imidazolidinyl urea, Compositae mix II (2.5% or 5% pet), linalool hydroperoxides (lin‐OOH), limonene hydroperoxides (lim‐OOH), benzisothiazolinone (BIT), octylisothiazolinone (OIT), decyl glucoside, and lauryl glucoside; Evernia furfuracea (tree moss), was additionally tested by some departments as well. Objectives: To collect further data on patch test reactivity and clinical relevance of the audit allergens in consecutive patients across Europe. Methods: Patch test data covering the audit allergens in 2019 and 2020 were collected by those departments of the European Surveillance System on Contact Allergies testing these, as well as further collaborators from the EBS working group of the European Society of Contact Dermatitis (ESCD), and the Spanish Grupo Español de Investigación en Dermatitis de Contacto y Alergia Cutánea. As patch test outcome, reactions between day (D) 3 and D5 were considered. Results: Altogether n = 12 403 patients were tested with any of the audit allergen. Positive reactions were most common to lin‐OOH 1% pet. (8.74% [95%CI: 8.14–9.37%]), followed by lin‐OOH 0.5% pet., and lim‐OOH 0.3% pet (5.41% [95% CI: 4.95–5.89%]). Beyond these terpene hydroperoxides, BIT 0.1% pet. was the second most common allergen with 4.72% (95% CI: 4.2–5.28%), followed by sodium metabisulfite 1% pet. (3.75% [95%CI: 3.32–4.23%]) and Compositae mix 5% pet. (2.31% [95% CI: 1.84–2.87%]). For some allergens, clinical relevance was frequently difficult to ascertain. Conclusions: Despite many positive patch test reactions, it remains controversial whether lin‐ and lim‐OOH should be tested routinely, while at least the two preservatives BIT and sodium metabisulfite appear suitable. The present results are a basis for further discussion and ultimately decision on their implementation into routine testing among the ESCD members. Highlights: Twelve preservatives, fragrances, and emulsifiers were evaluated as potential additions to the European Baseline Series (EBS)The highest prevalences of positive reactions were to linalool hydroperoxides 1% pet. or 0.5% pet. and limonene hydroperoxides 0.3% pet. Benzisothiazolinone 0.1% pet. was positive in 4.7%, followed by sodium metabisulfite 1% pet. (3.8%) and Compositae mix 5% pet. (2.3%).The results are a basis for further discussion and ultimately a decision on their implementation into routine testing among the European Society of Contact Dermatitis (ESCD) members. [ABSTRACT FROM AUTHOR]

Background: In 2019, a number of allergens (haptens), henceforth, "the audit allergens," were considered as potential additions to the European Baseline Series (EBS), namely, sodium metabisulfite, 2‐bromo‐2‐nitropropane‐1,3‐diol, diazolidinyl urea, imidazolidinyl urea, Compositae mix II (2.5% or 5% pet), linalool hydroperoxides (lin‐OOH), limonene hydroperoxides (lim‐OOH), benzisothiazolinone (BIT), octylisothiazolinone (OIT), decyl glucoside, and lauryl glucoside; Evernia furfuracea (tree moss), was additionally tested by some departments as well. Objectives: To collect further data on patch test reactivity and clinical relevance of the audit allergens in consecutive patients across Europe. Methods: Patch test data covering the audit allergens in 2019 and 2020 were collected by those departments of the European Surveillance System on Contact Allergies testing these, as well as further collaborators from the EBS working group of the European Society of Contact Dermatitis (ESCD), and the Spanish Grupo Español de Investigación en Dermatitis de Contacto y Alergia Cutánea. As patch test outcome, reactions between day (D) 3 and D5 were considered. Results: Altogether n = 12 403 patients were tested with any of the audit allergen. Positive reactions were most common to lin‐OOH 1% pet. (8.74% [95%CI: 8.14–9.37%]), followed by lin‐OOH 0.5% pet., and lim‐OOH 0.3% pet (5.41% [95% CI: 4.95–5.89%]). Beyond these terpene hydroperoxides, BIT 0.1% pet. was the second most common allergen with 4.72% (95% CI: 4.2–5.28%), followed by sodium metabisulfite 1% pet. (3.75% [95%CI: 3.32–4.23%]) and Compositae mix 5% pet. (2.31% [95% CI: 1.84–2.87%]). For some allergens, clinical relevance was frequently difficult to ascertain. Conclusions: Despite many positive patch test reactions, it remains controversial whether lin‐ and lim‐OOH should be tested routinely, while at least the two preservatives BIT and sodium metabisulfite appear suitable. The present results are a basis for further discussion and ultimately decision on their implementation into routine testing among the ESCD members. Highlights: Twelve preservatives, fragrances, and emulsifiers were evaluated as potential additions to the European Baseline Series (EBS)The highest prevalences of positive reactions were to linalool hydroperoxides 1% pet. or 0.5% pet. and limonene hydroperoxides 0.3% pet. Benzisothiazolinone 0.1% pet. was positive in 4.7%, followed by sodium metabisulfite 1% pet. (3.8%) and Compositae mix 5% pet. (2.3%).The results are a basis for further discussion and ultimately a decision on their implementation into routine testing among the European Society of Contact Dermatitis (ESCD) members. [ABSTRACT FROM AUTHOR]

Copyright of Polish Journal of Allergology / Alergologia Polska is the property of Termedia Publishing House and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A novel concept was successfully evaluated for the electrochemical quantitative analysis of zinc oxide nanoparticles originally in aqueous suspension. An aliquot of the suspension was first placed on the working area of a graphite screen-printed electrode and the water was evaporated to form a dry deposit of ZnO nanoparticles. Deposition of ZnO nanoparticles on the electrode was confirmed by energy-dispersive X-ray spectroscopy. A probe solution containing KCl and sodium metabisulfite was added on top of the deposit for electrochemical analysis by cyclic voltammetry. The anodic peak current (Ipa) for metabisulfite, measured at +1.2 V vs. Ag/AgCl, afforded a lower detection limit of 3 µg and exhibited a linear dependence on the mass of deposited ZnO nanoparticles up to 15 μg. Further, the current increased nonlinearly until it reached a saturation level beyond 60 μg of ZnO nanoparticles. The diffusion coefficient of metabisulfite anions through the electrical double layer was determined to be 4.16 × 10−5 cm2/s. Apparently the surface reactivity of ZnO originated from the oxide anion rather than the superoxide anion or the hydroxyl radical. Enhancement of the metabisulfite oxidation peak current can be developed into a sensitive method for the quantitation of ZnO nanoparticles. [ABSTRACT FROM AUTHOR]

In order to prompt the appearance of the shrimp color, sodium metabisulfite is frequently added in shrimp processing, which is, however, prohibited in China and many other countries. This study aimed to establish a surface-enhanced Raman spectroscopy (SERS) method for screening sodium metabisulfite residues on shrimp surfaces, in a non-destructive manner. The analysis was carried out using a portable Raman spectrometer jointly with copy paper loaded with silver nanoparticles as the substrate material. The SERS response of sodium metabisulfite gives two fingerprint peaks at 620 (strong) and 927 (medium) cm−1, respectively. This enabled unambiguous confirmation of the targeted chemical. The sensitivity of the SERS detection method was determined to be 0.1 mg/mL, which was equal to residual sodium metabisulfite on the shrimp surface at 0.31 mg/kg. The quantitative relationship between the 620 cm−1 peak intensities and the concentrations of sodium metabisulfite was established. The linear fitting equation was y = 2375x + 8714 with R2 = 0.985. Reaching an ideal balance in simplicity, sensitivity, and selectivity, this study demonstrates that the proposed method is ideally suitable for in-site and non-destructive screening of sodium metabisulfite residues in seafood.