Sulfite sensitivity: significance in human health

Health effects of synthetic additives and the substitution potential of plant-based additives

The growth of the world population and the rapid industrialization of food have led to food producers' increased reliance on food additives. While food additives offer numerous conveniences and advantages in food applications, the potential risks associated with synthetic additives remain a significant concern. This report examines the current status of safety assessment and toxicity studies of common synthetic additives, including flavorings (sweeteners and flavor enhancers), colorants, preservatives (antimicrobials and antioxidants), and emulsifiers. The report also examines recent advances in promising plant-based alternative additives in terms of active ingredients, sensory properties, potential health benefits, food application challenges, and their related technologies (edible coatings/films and nanoencapsulation technologies), providing valuable references and insights for the sustainable development of food additives.

Quantification of Total Sulfites in Shrimp by BIOFISH 300/3000 SUL Method, Collaborative Study: Final Action 2021.09

BACKGROUND

In December 2021, the BIOFISH 300 SUL method for the determination of total sulfites in shrimp was adopted as a First Action Official Method of AnalysisSM by the AOAC INTERNATIONAL.

OBJECTIVE

A collaborative study was conducted in February 2023 in order to test the reproducibility of the method.

METHODS

The method is based on the use of a benchtop biosensor device that relates the concentration of sulfite to a quantifiable electric current signal. The sensing element, the Biotest, harbors an enzyme that specifically oxidizes sulfite, and the reaction products are electrochemically detected by the device in less than 3 min. The sulfite is extracted from the solid using an aqueous-based buffer solution, which ensures that all sulfite is present as a free anion.

RESULTS

Eleven collaborators participated in the study of nine different shrimp samples. Values of repeatability and reproducibility relative standard deviation (RSDr and RSDR) obtained from the statistical analysis of valid data ranged from 2.1-8.1% and 7.5-14.3%, respectively, for shrimp samples above the quantification limit of the method, set at 7 mg/kg.

CONCLUSION

These results showed good repeatability and reproducibility of the method, even at concentrations below the legal threshold for sulfite in food, where the reference optimised Monier-Williams (OMW) method shows relatively high imprecision.

HIGHLIGHTS

On the basis of these results, the enzymatic amperometric biosensor method developed by BIOLAN Microbiosensores was adopted as Final Action Official Method in September 2023.

A dual-functional NIR fluorescence probe for detecting hypochlorous acid and bisulfite in biosystem

BACKGROUND

Bisulfite (HSO3-) serves as a bleaching agent, antioxidant, antimicrobial, and regulator of enzymatic reactions in biosystem. However, abnormal levels of bisulfite can be detrimental to health. Hypochlorous acid (HOCl), which acts as bioactive small molecules, is crucial for maintaining normal biological functions in living organisms. Disruption of its equilibrium can lead to oxidative stress and various diseases. Therefore, it's essential to monitor the fluctuations of HOCl and HSO3- at cellular and in vivo levels to study their physiological and pathological functions.

RESULTS

This study constructed a novel NIR bifunctional colorimetric fluorescent probe using thienocoumarin-indanedione structures to identify hypochlorite (ClO-) and bisulfite (HSO3-). By using CSO-IO to recognize HSO3- and HOCl, two distinct products were generated, displaying green and blue fluorescence, respectively. This property effectively allows for the simultaneous dual-functional detection of HSO3- (LOD: 113 nM) and HOCl (LOD: 43 nM).

SIGNIFICANCE

In this work, the biocompatible molecule CSO-IO has been effectively designed to detect HOCl/HSO3- in living cells and zebrafish. As a result, the dual-functional fluorescent probe has the potential to be utilized as a molecular tool to detect HSO3- derived compounds and HOCl simultaneously within the complex biological system.

Two-Stage Screening of Metschnikowia spp. Bioprotective Properties: From Grape Juice to Fermented Must by Saccharomyces cerevisiae

Gluconobacter oxydans (Go) and Brettanomyces bruxellensis (Bb) are detrimental micro-organisms compromising wine quality through the production of acetic acid and undesirable aromas. Non-Saccharomyces yeasts, like Metschnikowia species, offer a bioprotective approach to control spoilage micro-organisms growth. Antagonist effects of forty-six Metschnikowia strains in a co-culture with Go or Bb in commercial grape juice were assessed. Three profiles were observed against Go: no effect, complete growth inhibition, and intermediate bioprotection. In contrast, Metschnikowia strains exhibited two profiles against Bb: no effect and moderate inhibition. These findings indicate a stronger antagonistic capacity against Go compared to Bb. Four promising Metschnikowia strains were selected and their bioprotective impact was investigated at lower temperatures in Chardonnay must. The antagonistic effect against Go was stronger at 16 °C compared to 20 °C, while no significant impact on Bb growth was observed. The bioprotection impact on Saccharomyces cerevisiae fermentation has been assessed. Metschnikowia strains' presence did not affect the fermentation time, but lowered the fermentation rate of S. cerevisiae. An analysis of central carbon metabolism and volatile organic compounds revealed a strain-dependent enhancement in the production of metabolites, including glycerol, acetate esters, medium-chain fatty acids, and ethyl esters. These findings suggest Metschnikowia species' potential for bioprotection in winemaking and wine quality through targeted strain selection.

Quantification of Total Sulfite in Shrimps by BIOFISH 300 SUL Method: First Action 2021.09

BACKGROUND

Sulfite is the oldest and most widely used additive in our food supply with antioxidant and preservative properties. Due to its allergenic-like reactions and other adverse health effects, its use is regulated by international regulatory bodies. Therefore, food industries as well as regulatory laboratories must ensure that the maximum concentration of sulfite permitted is not exceeded. The AOAC INTERNATIONAL-approved official method for the quantification of sulfites is the Optimized Monier-Williams Method (AOAC Official Method 990.28), which consists of a time-consuming titration.

OBJECTIVE

The present study aims to demonstrate the reliability of the BIOFISH 300 SUL, a simple, fast, and accurate method, as an alternative, for the quantification of total sulfites in shrimp, with a lower LOQ than that of the OMA 990.28, set at 10 mg/Kg.

METHODS

The BIOFISH 300 SUL method is a highly specific biosensor based on its proprietary enzyme-based electrode, for the rapid quantification of total sulfite. The test kit consists of an electrochemical reader (biosensor BIOFISH 300) and disposable electrodes (Biotest) that are capable of providing an electrical signal proportional to the amount of sulfite in the sample analyzed. The method mainly consists of the extraction of sulfite from the solid matrix in an aqueous solution, and its subsequent quantification by the device in less than 3 min.

RESULTS

Comparative studies between BIOFISH 300 SUL and OMA 990.28 were conducted for naturally contaminated and spiked samples of raw and boiled shrimp with sulfite levels covering the 7-150 mg/kg range in order to determine linearity, recovery, repeatability, intermediate reproducibility, and accuracy.

CONCLUSION

The BIOFISH 300 SUL method demonstrated high accuracy and precision for the whole range of quantification (7-150 mg/kg). Its ease of use and fast response make it the ideal technology to be implemented by the industry.

HIGHLIGHTS

BIOFISH 300 SUL was adopted as a First Action Official MethodSM by the AOAC Expert Review Panel for Sulfites in Seafood Methods in February 2021 after rigorous review.

Chemical Methods for Microbiological Control of Winemaking: An Overview of Current and Future Applications

Preservation technologies for winemaking have relied mainly on the addition of sulfur dioxide (SO2), in consequence of the large spectrum of action of this compound, linked to the control of undesirable microorganisms and the prevention of oxidative phenomena. However, its potential negative effects on consumer health have addressed the interest of the international research on alternative treatments to substitute or minimize the SO2 content in grape must and wine. This review is aimed at analyzing chemical methods, both traditional and innovative, useful for the microbiological stabilization of wine. After a preliminary description of the antimicrobial and technological properties of SO2, the additive traditionally used during wine production, the effects of the addition (in must and wine) of other compounds officially permitted in winemaking, such as sorbic acid, dimethyl dicarbonate (DMDC), lysozyme and chitosan, are discussed and evaluated. Furthermore, other substances showing antimicrobial properties, for which the use for wine microbiological stabilization is not yet permitted in EU, are investigated. Even if these treatments exhibit a good efficacy, a single compound able to completely replace SO2 is not currently available, but a combination of different procedures might be useful to reduce the sulfite content in wine. Among the strategies proposed, particular interest is directed towards the use of insect-based chitosan as a reliable alternative to SO2, mainly due to its low environmental impact. The production of wines containing low sulfite levels by using pro-environmental practices can meet both the consumers’ expectations, who are even more interested in the healthy traits of foods, and wine-producers’ needs, who are interested in the use of sustainable practices to promote the profile of their brand.

The Role of Acetylcholine on the Effects of Different Doses of Sulfite in Learning and Memory

In this study, the effects of different doses of sulfite on learning, memory, and long term potentiation as well as the relationship of these effects with acetylcholine pathways, Arc and synapsin 1 levels were investigated. Sixty male Wistar albino rats were randomly divided into three groups as control, S100, and S260. Sodiummetabisulfite (S100;100 mg/kg/day, S260;260 mg/kg/day) was given by oral administration. Behavioral changes were evaluated. After long term potentiation recordings from the perforant pathway-dentate gyrus synapses, animals were sacrificed. Acetylcholinesterase activity, choline acetyltransferase activity, acetylcholine level as well as Arc and Synapsin 1 expressions were analyzed on the hippocampi. The total distance and average velocity values in the open field and Morris water maze tests increased in the sulfite groups, while the discrimination index in the novel object recognition test decreased compared to controls. Acetylcholine levels and choline acetyltransferase activity were also increased in the sulfite groups, while acetylcholinesterase activity was decreased compared to controls. Sulfite intake attenuated long term potentiation in the hippocampus. It has been observed that the excitatory postsynaptic potential slope and population spike amplitude of the field potentials obtained in sulfite groups decreased. This impairment was accompanied by a decrease in Arc and synapsin 1 expressions. In conclusion, it has been shown that sulfite intake in adults impairs learning and memory, possibly mediated by the cholinergic pathway. It is considered that the decrement in Arc and synapsin expressions may play a role in the mechanism underlying the impairment in long term potentiation caused by toxicity.

Ozone in wineries and wine processing: A review of the benefits, application, and perspectives

Ozone (O₃ ) is an emerging eco-friendly technology that has been widely used in the beverage industry due to its broad spectrum of usages, such as fermentation, microbial inactivation, Clean-in-Place (CIP) systems, and postharvest treatment. Wine is among the most financially profitable sectors of the beverage industry. Ozone technology as an alternative approach to conventional methods to inhibit microbes in wine processing and wineries has attracted researchers' attention as this emerging technology will probably play important roles in wineries in the future. This review discusses the prospective applications of ozone in winemaking and wineries and elaborates on ozone's antimicrobial effects on the control of the broad spectrum of microorganisms during wine processing. Also, this paper provides discussions on its effects of O₃  on wine quality and the benefits this emerging technology can bring to wineries. Ozone treatments can improve yeast fermentation by impacting the yeast ecology of postharvested wine grapes, mainly by affecting apiculate yeasts and adjusting the population of undesirable yeasts, such as Brettanomyces spp., during the fermentation process. Furthermore, ozone treatment may enhance wine's anthocyanin concentration, physicochemical properties, color, pH, oxidative stability, and concentration of pleasant volatile compounds and esters. This article presents important information to have a better understanding of the impact of ozone treatment on different stages of wine preparation.

Differentiation of Protonated Sulfonate Esters from Isomeric Sulfite Esters and Sulfones by Gas-Phase Ion-Molecule Reactions Followed by Diagnostic Collision-Activated Dissociation in Tandem Mass Spectrometry Experiments

Sulfonate esters, a class of potentially mutagenic drug impurities, are strictly regulated in pharmaceuticals. On the other hand, sulfite esters and sulfones, analogs of sulfonate esters, have limited safety concerns. However, previously developed analytical methods for sulfonate ester identification cannot be used to differentiate sulfonate esters from the isomeric sulfite esters and sulfones. A tandem mass spectrometric method is introduced here for the differentiation of these compounds. Diisopropoxymethylborane (DIMB) reacts with protonated sulfonate esters, sulfite esters, and sulfones (and many other compounds) in the gas phase to form the product ion [M + H + DIMB - CH₃CH(OH)CH₃]⁺. Upon collision-activated dissociation (CAD), these product ions generate diagnostic fragment ions that enable the differentiation of sulfonate esters, sulfite esters, and sulfones from each other. For example, SO₂ elimination enabled the unambiguous identification of sulfite esters. On the other hand, elimination of CH₃B═O followed by elimination of (CH₃)₂C═O was only observed for sulfonate esters. Neither type of diagnostic fragment ions was detected for the products of sulfones. However, the product ions formed for sulfones with an additional hydroxyl substituent underwent the elimination of another CH₃CH(OH)CH₃ molecule, which enabled their identification. Finally, ion-molecule reactions of DIMB with various other functionalities were also examined. Some of them yielded the product ions [M + H + DIMB - CH₃CH(OH)CH₃]⁺ but none of these product ions underwent the diagnostic CAD reactions discussed above. Quantum chemical calculations were employed to explore the mechanisms of the reactions. The limits of detection for the diagnostic ion-molecule reaction product ions in high-performance liquid chromatography (HPLC)/mass spectrometry (MS²) experiments were found to range from 0.075 to 1.25 nmol.

Fluorogenic Detection of Sulfite in Water by Using Copper(II) Azacyclam Complexes

Copper(II) azacyclam complexes (azacyclam = 1,3,5,8,12-pentaazacyclotetradecane) containing naphthyl or dansyl subunits can be prepared by template synthesis involving proper sulfonamide derivatives as locking fragments. The macrocyclic complexes are very poorly emissive due to the fluorescence-quenching behavior displayed by Cu²⁺ ions. However, the fluorescence can be recovered as a result of the decomposition of the complexes, which induces the release of free light-emitting subunits to the solution. This reaction takes place very slowly in neutral water but its rate is increased by the presence of sulfite. Therefore, [Cu(azacyclam)]²⁺ derivatives have been investigated as simple chemical probes for the fluorogenic detection of sulfite both on laboratory and real samples. Preliminary tests performed on samples of white wine provided sulfite concentration values that are in agreement with those obtained by a standard analytical method.

Sodium sulfite causes gastric mucosal cell death by inducing oxidative stress

Sulfites are commonly used as a preservative and antioxidant additives in the food industry. Sulfites are absorbed by the gastrointestinal tract and distributed essentially to all body tissues. Although sulfites have been believed to be safe food additives, some studies have shown that they exhibit adverse effects in various tissues. In this study, we examined the cytotoxic effect of sodium sulfite (Na₂SO₃) against rat gastric mucosal cells (RGM1) and further investigated its underlying molecular mechanism. We demonstrated that exposure to Na₂SO₃ exerts significant cytotoxicity in RGM1 cells through induction of oxidative stress. Exposure of RGM1 cells to Na₂SO₃ caused a significant formation of protein carbonyls and 8-hydroxy-2'-deoxyguanosine, major oxidative stress markers, with a concomitant accumulation of carbonylated protein-related aggregates. Furthermore, we found that incubation of lysozyme with Na₂SO₃ evokes protein carbonylation and aggregation via the metal ion-catalyzed free radical formation derived from Na₂SO₃. Our results suggest that Na₂SO₃ might lead to gastric tissue injury via induction of oxidative stress by the formation of Na₂SO₃-related free radicals.

Molybdenum Enzymes and How They Support Virulence in Pathogenic Bacteria

Mononuclear molybdoenzymes are highly versatile catalysts that occur in organisms in all domains of life, where they mediate essential cellular functions such as energy generation and detoxification reactions. Molybdoenzymes are particularly abundant in bacteria, where over 50 distinct types of enzymes have been identified to date. In bacterial pathogens, all aspects of molybdoenzyme biology such as molybdate uptake, cofactor biosynthesis, and function of the enzymes themselves, have been shown to affect fitness in the host as well as virulence. Although current studies are mostly focused on a few key pathogens such as Escherichia coli, Salmonella enterica, Campylobacter jejuni, and Mycobacterium tuberculosis, some common themes for the function and adaptation of the molybdoenzymes to pathogen environmental niches are emerging. Firstly, for many of these enzymes, their role is in supporting bacterial energy generation; and the corresponding pathogen fitness and virulence defects appear to arise from a suboptimally poised metabolic network. Secondly, all substrates converted by virulence-relevant bacterial Mo enzymes belong to classes known to be generated in the host either during inflammation or as part of the host signaling network, with some enzyme groups showing adaptation to the increased conversion of such substrates. Lastly, a specific adaptation to bacterial in-host survival is an emerging link between the regulation of molybdoenzyme expression in bacterial pathogens and the presence of immune system-generated reactive oxygen species. The prevalence of molybdoenzymes in key bacterial pathogens including ESKAPE pathogens, paired with the mounting evidence of their central roles in bacterial fitness during infection, suggest that they could be important future drug targets.

Postharvest application of thiol compounds affects surface browning and antioxidant activity of fresh-cut potatoes

The aim of this study was to compare the effects of sodium metabisulphite and the thiol compounds, glutathione (GSH), L-cysteine (CYS), and N-acetylcysteine (NAC), on the enzymatic browning, antioxidant activities, total phenolic, and ascorbic acid content of potatoes after 1, 24, and 48 hr. Three different concentrations (0.5%, 1.0%, and 2.0%) of each thiol compound were tested. While sulphite solution inhibited polyphenol oxidase as expected, NAC and CYS also decreased its activity. CYS-treated samples exhibited the highest residual thiol content, while the amount of residual thiol in GSH-treated samples was the lowest. The 2.0% NAC and 2.0% CYS solutions were the most effective at increasing antioxidant activity and ascorbic acid content; however, the results of total phenolic content assays were complicated. In summary, solutions containing 2.0% NAC, 1.0% CYS, and 2.0% CYS prevented enzymatic browning and increased the residual thiol content, ascorbic acid, and antioxidant activities of fresh-cut potatoes significantly, but GSH did not significantly inhibit browning. PRACTICAL APPLICATIONS: Fresh-cut potatoes are susceptible to enzymatic browning, which significantly reduces their commercial value. In literature, there have been several methods to protect the enzymatic browning of fruits and vegetables. Among these methods, thiols are good inhibitors of enzymatic browning. So, GSH, CYS, and NAC were used in this study. The outcomes of current work may help to inhibit polyphenol oxidase activity and increase the ascorbic acid content, residual thiol content, and antioxidant activity of fresh-cut potatoes. Both CYS and NAC may be useful alternatives to sulphite anti-browning agents, which may have adverse health effects.

Resveratrol: A Fair Race Towards Replacing Sulfites in Wines

In recent years, significant efforts to produce healthier wines has led to the replacement or reduction of the addition of sulfites, using alternative substances or techniques. Resveratrol and related biophenols seem to be of great interest, since beyond their protective nature and contrary to sulfites they can positively affect consumer health. These bioactive phytochemicals are naturally produced in grapes as evolutionary acquired mechanisms against pathogens and UV irradiation. However, despite the efforts made so far attempting to develop economic and industrially adopted isolation techniques, available quantities of these biophenols for commercial use are still quite limited. Therefore, such molecules are still not able to meet the needs of industrial use due to their prohibitive marketable cost. In this review we summarize the efforts that have been made to biosynthesize these molecules through alternative, innovative ways. Increasing interest in modern biotechnological approaches has shed light on the exploitation of metabolically engineered microbial factories, instead of plants, to produce molecules of industrial interest. Such approaches, also reviewed here, are expected to lower the cost and appear promising to produce enough surplus to attract further oenological experimentation upon yielding functional wines. This development is expected to attract further industrial attention, continuing the race to partially or totally replace the external addition of sulfites. We also review important physicochemical properties of resveratrol in relation to enriching wines.

An effective biocompatible fluorescent probe for bisulfite detection in aqueous solution, living cells, and mice

Sulfur dioxide, an air pollutant, is easily hydrated to sulfites and bisulfites and extremely harmful to human health. On the other hand, endogenous sulfur dioxide is the fourth gasotransmitter. In view of the above, it is worth developing an effective method for the detection of these compounds. In this paper, a novel colorimetric fluorescent probe (Hcy-Mo), based on hemi-cyanine, for bisulfites is reported. Hcy-Mo shows excellent selectivity for bisulfites over various other species including cysteine, glutathione, CN⁻, and HS⁻, and undergoes 1,4-addition reactions at the C-4 atom of the ethylene group. The reaction can be completed in 30 s in a PBS buffer solution and displays high sensitivity (limit of detection is 80 nM) for bisulfites. Test paper experiments show that the probe can be used for bisulfite detection in aqueous solutions. In addition, Hcy-Mo exhibits excellent cell permeability and low cytotoxicity for the successful detection of bisulfites in living MDA-MB-231 cells and in living mice, implying that this probe would be of great benefit to biological researchers for investigating the detailed biological and pharmacological functions of bisulfites in biological systems.

Sulfur dioxide, an air pollutant, is easily hydrated to sulfites and bisulfites and extremely harmful to human health.

Wine Lactic Acid Bacteria with Antimicrobial Activity as Potential Biocontrol Agents against Fusarium oxysporum f. sp. lycopersici

Lactic acid bacteria isolated from wine fermentations, particularly from the malolactic fermentation, and belonging to Lactobacillus plantarum, Lactobacillus hilgardii, Lactobacillus paracasei and Lactococcus lactis species were tested for their effectiveness in inhibiting the development of different microorganisms. The different strains showed, to varying degrees, an antagonistic effect against bacteria of the genera Bacillus and Staphylococcus. The specificity of the species L. hilgardii that inhibits only strains of the genus Bacillus is remarkable, on the other hand, L. plantarum was more effective against the strains of the genus Staphylococcus. The greatest effectiveness, considering both the degree of inhibition and the number of inhibited species, was presented by strains of L. lactis and L. paracasei. Seven strains belonging to the species that showed a more broad-spectrum activity, L. paracasei and L. plantarum, were also tested for their ability to inhibit the growth of fungi. All of them showed, in different degree (55–76%), activity against Fusarium oxysporum. Finally, the ability of the L. paracasei LPAUV12 and L. plantarum LPLUV10 strains was evaluated to protect Lycopersicon esculentum plants against the fungus F. oxysporum and promote its growth. Strain LPLUV10, showed capacity to significantly inhibit the harmful effect of F. oxysporum in tomato plants as well as to significantly stimulate their growth.

Traditional and Unconventional Dried Fruit Snacks as a Source of Health-Promoting Compounds

Dried fruits are important, healthy and popular snacks, despite the limited information on their nutritional profiles and phytochemical composition. The present work was aimed to study the chemical composition of freeze-dried fruits from four fruit species: two common commercial snacks (apple and goji) and two innovative products (kaki and kiwi). Sugar and organic acid levels, total phenolics (TPC), and main health-promoting phytochemicals were studied by HPLC fingerprinting analysis. Furthermore, in vitro antioxidant capacity (AOC) was preliminarily observed in these products. A Principal Component Analysis (PCA) was carried out as a multivariate approach as well. The TPC ranged from 210.9 mg GAE/100g DW (kiwi) to 872.6 mg GAE/100g DW (kaki), while dried fruit antioxidant capacity ranged from 23.09 mmol Fe²⁺/kg DW (goji) to 137.5 mmol Fe²⁺/kg DW (kaki). The most important phytochemical class in apple (two cultivars), kiwi, and kaki dried fruits was phenolics (from 74.6% to 93.3%), while monoterpenes were the first class in goji (67.5%). No anthocyanins have been identified in dried fruits because these compounds are most likely converted to phenolic acids during the drying process. This research intended to stimulate large-scale exploitation of commercial dried fruits as functional foods as well.

An unprecedented oxidised julolidine-BODIPY conjugate and its application in real-time ratiometric fluorescence sensing of sulfite

Reaction of a julolidine-based BODIPY compound with silver(i) ions in the presence of white light produced the oxidised julolidine version (OXJUL) containing a quaternary nitrogen. The oxidation of one ring at the julolidine site is highly unusual and there is no other reported literature example. The fluorescence maximum of OXJUL is altered from 648 nm to 608 nm by the addition of an aqueous solution of Na2SO3 over several minutes. In the presence of a large excess of sulfite a further slower reaction is observed which further shifts the emission maximum to 544 nm. The alterations form the basis of a real-time ratiometric sensor for sulfite and its detection in a white wine.

Hypersensitivity reactions to food and drug additives: problem or myth?

BACKGROUND AND AIM OF THE WORK

The possibility of an allergic reaction or an intolerance to additives is frequently suspected by parents, especially for chronic illness with frequent exacerbations such as atopic dermatitis or chronic urticaria. For more than 50 years, potential adverse reactions to additives have been suggested, but to date data are conflicting. The purpose of this article is to provide the clinicians with general information about additives and adverse reactions to them and to suggest a practical approach to children suspected to have reactions to food additives.

METHODS

We performed an extensive research on all English-language Medline articles, case reports and reviews published online until December 2018. Used search terms were: food additives, food dye, adverse reactions, food allergy, food hypersensitivity, intolerance, drugs, children.

RESULTS

There are only few case reports of adverse reactions in childhood with a clear involvement of additives. In this review article we reported the associations between additives and adverse reactions described in literature, in order to inform the pediatrician about the potential clinical manifestations.

CONCLUSIONS

Prior to suspect an adverse reaction to additives, it is important to rule out other possible causes: the diagnostic process is complicated and rarely conclusive. The gold standard is the double-blind placebo controlled oral challenge after an exclusion diet.

Acetaldehyde kinetics of enological yeast during alcoholic fermentation in grape must

Acetaldehyde strongly binds to the wine preservative SO2 and, on average, causes 50–70 mg l−1 of bound SO2 in red and white wines, respectively. Therefore, a reduction of bound and total SO2 concentrations necessitates knowledge of the factors that affect final acetaldehyde concentrations in wines. This study provides a comprehensive analysis of the acetaldehyde production and degradation kinetics of 26 yeast strains of oenological relevance during alcoholic fermentation in must under controlled anaerobic conditions. Saccharomyces cerevisiae and non-Saccharomyces strains displayed similar metabolic kinetics where acetaldehyde reached an initial peak value at the beginning of fermentations followed by partial reutilization. Quantitatively, the range of values obtained for non-Saccharomyces strains greatly exceeded the variability among the S. cerevisiae strains tested. Non-Saccharomyces strains of the species C. vini, H. anomala, H. uvarum, and M. pulcherrima led to low acetaldehyde residues (<10 mg l−1), while C. stellata, Z. bailii, and, especially, a S. pombe strain led to large residues (24–48 mg l−1). Acetaldehyde residues in S. cerevisiae cultures were intermediate and less dispersed (14–34 mg l−1). Addition of SO2 to Chardonnay must triggered significant increases in acetaldehyde formation and residual acetaldehyde. On average, 0.33 mg of residual acetaldehyde remained per mg of SO2 added to must, corresponding to an increase of 0.47 mg of bound SO2 per mg of SO2 added. This research demonstrates that certain non-Saccharomyces strains display acetaldehyde kinetics that would be suitable to reduce residual acetaldehyde, and hence, bound-SO2 levels in grape wines. The acetaldehyde formation potential may be included as strain selection argument in view of reducing preservative SO2 concentrations.

Final Report on the Safety Assessment of Sodium Sulfite, Potassium Sulfite, Ammonium Sulfite, Sodium Bisulfite, Ammonium Bisulfite, Sodium Metabisulfite and Potassium Metabisulfite

Sodium Sulfite, Ammonium Sulfite, Sodium Bisulfite, Potassium Bisulfite, Ammonium Bisulfite, Sodium Metabisulfite, and Potassium Metabisulfite are inorganic salts that function as reducing agents in cosmetic formulations. All except Sodium Metabisulfite also function as hair-waving/straightening agents. In addition, Sodium Sulfite, Potassium Sulfite, Sodium Bisulfite, and Sodium Metabisulfite function as antioxidants. Although Ammonium Sulfite is not in current use, the others are widely used in hair care products. Sulfites that enter mammals via ingestion, inhalation, or injection are metabolized by sulfite oxidase to sulfate. In oral-dose animal toxicity studies, hyperplastic changes in the gastric mucosa were the most common findings at high doses. Ammonium Sulfite aerosol had an acute LC50 of >400 mg/m3 in guinea pigs. A single exposure to low concentrations of a Sodium Sulfite fine aerosol produced dose-related changes in the lung capacity parameters of guinea pigs. A 3-day exposure of rats to a Sodium Sulfite fine aerosol produced mild pulmonary edema and irritation of the tracheal epithelium. Severe epithelial changes were observed in dogs exposed for 290 days to 1 mg/m3 of a Sodium Metabisulfite fine aerosol. These fine aerosols contained fine respirable particle sizes that are not found in cosmetic aerosols or pump sprays. None of the cosmetic product types, however, in which these ingredients are used are aerosolized. Sodium Bisulfite (tested at 38%) and Sodium Metabisulfite (undiluted) were not irritants to rabbits following occlusive exposures. Sodium Metabisulfite (tested at 50%) was irritating to guinea pigs following repeated exposure. In rats, Sodium Sulfite heptahydrate at large doses (up to 3.3 g/kg) produced fetal toxicity but not teratogenicity. Sodium Bisulfite, Sodium Metabisulfite, and Potassium Metabisulfite were not teratogenic for mice, rats, hamsters, or rabbits at doses up to 160 mg/kg. Generally, Sodium Sulfite, Sodium Metabisulfite, and Potassium Metabisulfite were negative in mutagenicity studies. Sodium Bisulfite produced both positive and negative results. Clinical oral and ocular-exposure studies reported no adverse effects. Sodium Sulfite was not irritating or sensitizing in clinical tests. These ingredients, however, may produce positive reactions in dermatologic patients under patch test. In evaluating the positive genotoxicity data found with Sodium Bisulfite, the equilibrium chemistry of sulfurous acid, sulfur dioxide, bisulfite, sulfite, and metabisulfite was considered. This information, however, suggests that some bisulfite may have been present in genotoxicity tests involving the other ingredients and vice versa. On that basis, the genotoxicity data did not give a clear, consistent picture. In cosmetics, however, the bisulfite form is used at very low concentrations (0.03% to 0.7%) in most products except wave sets. In wave sets, the pH ranges from 8 to 9 where the sulfite form would predominate. Skin penetration would be low due to the highly charged nature of these particles and any sulfite that did penetrate would be converted to sulfate by the enzyme sulfate oxidase. As used in cosmetics, therefore, these ingredients would not present a genotoxicity risk. The Cosmetic Ingredient Review Expert Panel concluded that Sodium Sulfite, Potassium Sulfite, Ammonium Sulfite, Sodium Bisulfite, Ammonium Bisulfite, Sodium Metabisulfite, and Potassium Metabisulfite are safe as used in cosmetic formulations.

The effect of ingested sulfite on active avoidance in normal and sulfite oxidase-deficient aged rats

The aim of this study was to investigate the possible toxic effects of sulfite on neurons by measuring active avoidance learning in normal and sulfite oxidase (SOX)-deficient aged rats. Twenty-four months of age Wistar rats were divided into four groups: control (C), sulfite-treated group (S), SOX-deficient group (D) and SOX-deficient + sulfite-treated group (DS). SOX deficiency was established by feeding rats with a low molybdenum (Mo) diet and adding 200 ppm tungsten (W) to their drinking water. Sulfite in the form of sodium metabisulfite (25 mg/kg) was given by gavage for six weeks. Active avoidance responses were determined by using an automated shuttle box. Hepatic SOX activity was measured to confirm SOX deficiency. The hippocampus was used for determining the activity of cyclooxygenase (COX) and caspase-3 enzymes and the level of prostaglandin E2 (PGE2) and nitrate/nitrite. SOX-deficient rats had an approximately 10-fold decrease in hepatic SOX activity compared with normal rats. Sulfite did not induce impairment of active avoidance learning in SOX-deficient rats and in normal rats compared with their control groups. Sulfite had no effect on the activity of COX and caspase-3 in the hippocampus. Treatment with sulfite did not significantly increase the level of PGE2 and nitrate/nitrite in the hippocampus.

Gastric mucosal irritation following oral exposure to sodium metabisulphite: A reproducible effect?

Sulphiting agents, such as sodium metabisulphite (SM), are used in food as bleaching agents and to prevent browning reactions. A 1972 repeat dose study in rats found that dietary sulphites caused irritation of the stomach with inflammation, hyperplasia and bleeding. We conducted a 7-day dietary study in rats to confirm that stomach lesions were the most sensitive toxicological endpoint. Rat feed was prepared daily with 0%, 0.25%, 0.5%, 1% or 4% (w/w) SM. Parameters included clinical signs, feed and water intake, bodyweight gain, haematology, serum protein chemistry, necropsy findings and gastrointestinal histopathology. There were no treatment-related clinical signs or gastrointestinal lesions. Mean bodyweight gain was markedly decreased in the 4% (w/w) SM group although feed consumption was marginally depressed. Slightly lower mean values for RBC, Hb, Hct, total WBC and lymphocyte count were observed in the 4% SM group with no evidence of compensatory haematopoiesis. The gastric lesions in rats observed in a 1972 study of dietary SM for 10-56 days could not be replicated. These findings create uncertainty around the most relevant toxicological endpoint to establish a suitable health based guidance value, which can only be overcome if a robust long-term dietary study is undertaken.

A fluorescent probe for bisulfite ions: its application to two-photon tissue imaging

Two-photon imaging of endogenous bisulphite ions of the hippocampus region of mouse brain.

Quality Characteristics and Quantification of Acetaldehyde and Methanol in Apple Wine Fermentation by Various Pre-Treatments of Mash

The objective of this study was to compare the effects of adding lactic acid and pectinase, and chaptalization for the quality of apple wine and the production of hazardous compounds (methanol and acetaldehyde). The pH of all of the samples was below 4; therefore, mash seemed to be fermented without any issue. Total acidity was the highest in sample A due to lactic acid addition. Pre-treated groups (samples B, C, and D) showed higher total acidities than that of the control (P<0.05). Pre-treatments might influence the production of organic acids in apple wines. The control and pectinase added sample (sample B) had the lowest alcohol contents. Adding lactic acid produced more alcohol, and chaptalized samples produced more alcohol due to the addition of sugar. Adding pectinase with and without chaptalization was not effective for producing more alcohol. The control sample had significantly higher acetaldehyde content (2.39 mg/L) than the other samples (1.00~2.07 mg/L); therefore, pre-treatments for apple wine fermentation produced a lower amount of acetaldehyde. Among the pre-treated samples, samples C and D showed the lowest acetaldehyde content of 1.00 mg/L and 1.16 mg/L, respectively. On the other hand, a significantly higher amount of methanol was generated for sample A (1.03 mg/L) and sample D (1.22 mg/L) than that of the control (0.82 mg/L) (P<0.05). Adding lactic acid or chaptalization was effective in reducing methanol and acetaldehyde in apple wines.

Investigation of the effects of a sulfite molecule on human neuroblastoma cells via a novel oncogene URG4/URGCP

AIM

The aim of this study is to determine the anticancer effect of sulfite on SH-SY5Y neuroblastoma cells in vitro conditions and elucidate underlying molecular mechanism of sulfite and explore its therapeutic activity.

MAIN METHODS

In this study, cytotoxic effects of sulfite in SH-SY5Y cels were detected over time in a dose dependent manner with the IC50 doses ranging from 0.5 to 10 mM. Genotoxic effect of sulfite was shown by comet assay. IC50 doses in the SH-SY5Y cells were detected as 5 mM. Expression profiles of the target genes related to apoptosis and cell cycle control were determined by quantitative RT-PCR. Protein changes were determined by western blot analysis.

KEY FINDINGS

URG4/URGCP, CCND1, CCND2, CDK4, CDK6, E2F4 and BCL-2 gene expression levels were significantly reduced and RB1, TP53, BAX, BID, CASP2, CASP3, CASP9 and DIABLO gene expressions were significantly increased in dose group cells. The mechanism of this result may be related to sulfite dependent inhibition of cell cycle at the G1 phase by down-regulating URG4/URGCP or CCND1, CDK4, CDK6 gene expression and stimulating apoptosis via the intrinsic pathway. Sulfite suppressed invasion and colony formation in SH-SY5Y cell line using matrigel invasion chamber and colony formation assay, respectively.

SIGNIFICANCE

It is thought that sulfite demonstrates anticarcinogenesis activity by affecting cell cycle arrest, apoptosis s, invasion, and colony formation on SH-SY5Y cells. Sulfite may be an effective agent for treatment of neuroblastoma as a single agent or in combination with other agents.

Acidic sweep gas with carbonic anhydrase coated hollow fiber membranes synergistically accelerates CO2 removal from blood

The use of extracorporeal carbon dioxide removal (ECCO2R) is well established as a therapy for patients suffering from acute respiratory failure. Development of next generation low blood flow (<500 mL/min) ECCO2R devices necessitates more efficient gas exchange devices. Since over 90% of blood CO2 is transported as bicarbonate (HCO3(-)), we previously reported development of a carbonic anhydrase (CA) immobilized bioactive hollow fiber membrane (HFM) which significantly accelerates CO2 removal from blood in model gas exchange devices by converting bicarbonate to CO2 directly at the HFM surface. This present study tested the hypothesis that dilute sulfur dioxide (SO2) in oxygen sweep gas could further increase CO2 removal by creating an acidic microenvironment within the diffusional boundary layer adjacent to the HFM surface, facilitating dehydration of bicarbonate to CO2. CA was covalently immobilized onto poly (methyl pentene) (PMP) HFMs through glutaraldehyde activated chitosan spacers, potted in model gas exchange devices (0.0151 m(2)) and tested for CO2 removal rate with oxygen (O2) sweep gas and a 2.2% SO2 in oxygen sweep gas mixture. Using pure O2 sweep gas, CA-PMP increased CO2 removal by 31% (258 mL/min/m(2)) compared to PMP (197 mL/min/m(2)) (P<0.05). Using 2.2% SO2 acidic sweep gas increased PMP CO2 removal by 17% (230 mL/min/m(2)) compared to pure oxygen sweep gas control (P<0.05); device outlet blood pH was 7.38 units. When employing both CA-PMP and 2.2% SO2 sweep gas, CO2 removal increased by 109% (411 mL/min/m(2)) (P<0.05); device outlet blood pH was 7.35 units. Dilute acidic sweep gas increases CO2 removal, and when used in combination with bioactive CA-HFMs has a synergistic effect to more than double CO2 removal while maintaining physiologic pH. Through these technologies the next generation of intravascular and paracorporeal respiratory assist devices can remove more CO2 with smaller blood contacting surface areas.

STATEMENT OF SIGNIFICANCE

A clinical need exists for more efficient respiratory assist devices which utilize low blood flow rates (<500 mL/min) to regulate blood CO2 in patients suffering from acute lung failure. Literature has demonstrated approaches to chemically increase hollow fiber membrane (HFM) CO2 removal efficiency by shifting equilibrium from bicarbonate to gaseous CO2, through either a bioactive carbonic anhydrase enzyme coating or bulk blood acidification with lactic acid. In this study we demonstrate a novel approach to local blood acidification using an acidified sweep gas in combination with a bioactive coating to more than double CO2 removal efficiency of HFM devices. To our knowledge, this is the first report assessing an acidic sweep gas to increase CO2 removal from blood using HFM devices.

The molecular mechanisms of sodium metabisulfite on the expression of K ATP and L-Ca2+ channels in rat hearts

Sodium metabisulfite (SMB) is used as an antioxidant and antimicrobial agent in a variety of drugs and foods. However, there are few reported studies about its side effects. This study is to investigate the SMB effects on the expression of ATP-sensitive K(+) (KATP) and L-type calcium (L-Ca(2+)) channels in rat hearts. The results show that the mRNA and protein levels of the KATP channel subunits Kir6.2 and SUR2A were increased by SMB; on the contrary, SMB at 520 mg/kg significantly decreased the expression of the L-Ca(2+) channel subunits Cav1.2 and Cav1.3. This suggests that SMB can activate the expression of KATP channel by increasing the mRNA and protein levels of Kir6.2 and SUR2A, while it inhibits the expression of L-Ca(2+) channels by decreasing the mRNA and protein levels of Cav1.2 and Cav1.3 in rat hearts. Therefore, the molecular mechanism of the SMB effect on rat hearts might be related to the increased expression of KATP channels and the decreased expression of L-Ca(2+) channels.

Polyphenol profiling of a red-fleshed apple cultivar and evaluation of the color extractability and stability in the juice

Red-fleshed apples can be used for the production of innovative products such as rosé juices and ciders. Phenolic compounds including procyanidins (i.e., condensed tannins) and anthocyanins were quantified in the fruits and juices of a red-fleshed apple cultivar by chromatography coupled to UV-visible and mass spectrometry. Juice color was characterized by colorimetry. The influence of oxygen, pH, sulfites, ascorbic acid, and copper on the color stability of the juice was studied in an experimental design. Fruits were rich in polyphenols (0.5 g/100 g FW), with anthocyanins and procyanidins accounting for 9 and 73% of total polyphenols, respectively. Extractability of anthocyanins in the juice was 26%. Juice storage under air atmosphere at 35 °C resulted in significant browning with the anthocyanin level decreasing up to 86% after 14 days. In contrast, color was stable for storage under argon atmosphere. Sulfites, ascorbic acid, and copper have only a slightly influence on color stability in those conditions.

Decreased immunoglobulin E (IgE) binding to cashew allergens following sodium sulfite treatment and heating

Cashew nut and other nut allergies can result in serious and sometimes life-threatening reactions. Linear and conformational epitopes within food allergens are important for immunoglobulin E (IgE) binding. Methods that disrupt allergen structure can lower IgE binding and lessen the likelihood of food allergy reactions. Previous structural and biochemical data have indicated that 2S albumins from tree nuts and peanuts are potent allergens, and that their structures are sensitive to strong reducing agents such as dithiothreitol. This study demonstrates that the generally regarded as safe (GRAS) compound sodium sulfite effectively disrupted the structure of the cashew 2S albumin, Ana o 3, in a temperature-dependent manner. This study also showed that sulfite is effective at disrupting the disulfide bond within the cashew legumin, Ana o 2. Immunoblotting and ELISA demonstrated that the binding of cashew proteins by rabbit IgG or IgE from cashew-allergic patients was markedly lowered following treatment with sodium sulfite and heating. The results indicate that incorporation of sodium sulfite, or other food grade reagents with similar redox potential, may be useful processing methods to lower or eliminate IgE binding to food allergens.

Allergic and immunologic reactions to food additives

For centuries, food additives have been used for flavouring, colouring and extension of the useful shelf life of food, as well as the promotion of food safety. During the last 20 years, the studies implicating the additives contained in foods and medicine as a causative factor of allergic reactions have been proliferated considerably. In this review, we aimed to overview all of the food additives which were approved to consume in EU and find out how common and serious allergic reactions come into existence following the consuming of food additives.

Curcumin can prevent the changes in cerebellar structure and function induced by sodium metabisulfite in rat

Sulfites are used as anti-microbial and anti-oxidant agents in the food and pharmaceutical industries. Curcumin, a flavonoid, is an Asian spice that shows neuroprotective activities. The current study aimed to stereologically assess the rats' cerebellar cortex and rotarod performance following sulfite exposure and determine the possible neuroprotective potential of curcumin. The rats were divided into five groups: distilled water, olive oil, curcumin (100 mg/kg/day), sodium metabisulfite (25 mg/kg/day), and sodium metabisulfite+curcumin. At 56 days after treatment, rotarod performance was tested, and then the cerebellum was removed for stereological analysis. The study results revealed 31%, 36%, 19% and 24% decrease in the total volume of the cerebellum, cortex, the total number of the Purkinje cells and length of the nerve fibers in the cortex per Purkinje, respectively in the sodium metabisulfite-treated rats compared to the distilled water group (p<0.01). The pre-trained animals on the rotarod apparatus were tested first on the fixed speed rotarod protocol followed by the accelerating rotarod protocol two days later. The results showed a significant decrease in the latency to fall in both test in sulfite-treated rats. The sulfite effects on the structural parameters and rotarod performance were significantly protected by the concomitant curcumin treatment (p<0.001). Sulfite can induce structural and functional changes in the rats' cerebellum and concomitant curcumin prescription plays a neuroprotective role.