Dietary intake exposure to sulphites in Italy--analytical determination of sulphite-containing foods and their combination into standard meals for adults and children

Sulfur content in foods and beverages and its role in human and animal metabolism: A scoping review of recent studies

Sulfur is a vital element that all living things require, being a component of proteins and other bio-organic substances. The various kinds and varieties of microbes in nature allow for the transformation of this element. It also should be emphasized that volatile sulfur compounds are typically present in food in trace amounts. Life cannot exist without sulfur, yet it also poses a potential health risk. The colon's sulfur metabolism, which is managed by eukaryotic cells, is much better understood than the S metabolism in gastrointestinal bacteria. Numerous additional microbial processes are anticipated to have an impact on the content and availability of sulfated compounds, as well as intestinal S metabolism. Hydrogen sulfide is the sulfur derivative that has attracted the most attention in relation to colonic health, but it is still unclear whether it is beneficial or harmful. Several lines of evidence suggest that sulfate-reducing bacteria or exogenous hydrogen sulfide may be the root cause of intestinal ailments, including inflammatory bowel diseases and colon cancer. Taurine serves a variety of biological and physiological purposes, including roles in inflammation and protection, additionally, low levels of taurine can be found in bodily fluids, and taurine is the primary sulfur component present in muscle tissue (serum and urine). The aim of this scoping review was to compile data from the most pertinent scientific works about S compounds' existence in food and their metabolic processes. The importance of S compounds in various food products and how these compounds can impact metabolic processes are both stressed in this paper.

Food Emulsifiers and Metabolic Syndrome: The Role of the Gut Microbiota

The use of emulsifiers in processed foods and the rapid epidemic development of metabolic syndrome in Western countries over the past 20 years have generated growing interest. Evidence for the role of emulsifiers in metabolic syndrome through gut microbiota has not been clearly established, thus making it challenging for clinical nutritionists and dietitians to make evidence-based associations between the nature and the quantity of emulsifiers and metabolic disorders. This narrative review summarizes the highest quality clinical evidence currently available about the impact of food emulsifiers on gut microbiota composition and functions and the potential development of metabolic syndrome. The state-of-the-art of the different common emulsifiers is performed, highlighting where they are present in daily foods and their roles. Recent findings of in vitro, in vivo, and human studies assessing the effect of different emulsifiers on gut microbiota have been recently published. There is some progress in understanding how some food emulsifiers could contribute to developing metabolic diseases through gut microbiota alterations while others could have prebiotic effects. However, there are still many unanswered questions regarding daily consumption amounts and the synergic effects between emulsifiers' intake and responses by the microbial signatures of each individual.

Exposure to food additive mixtures in 106,000 French adults from the NutriNet-Santé cohort

Food additives (e.g. artificial sweeteners, emulsifiers, dyes, etc.) are ingested by billions of individuals daily. Some concerning results, mainly derived from animal and/or cell-based experimental studies, have recently emerged suggesting potential detrimental effects of several widely consumed additives. Profiles of additive exposure as well as the potential long-term impact of multiple exposure on human health are poorly documented. This work aimed to estimate the usual intake of food additives among participants of the French NutriNet-Santé cohort and to identify and describe profiles of exposure (single substances and mixtures). Overall, 106,489 adults from the French NutriNet-Santé cohort study (2009-ongoing) were included. Consumption of 90 main food additives was evaluated using repeated 24 h dietary records including information on brands of commercial products. Qualitative information (as presence/absence) of each additive in food products was determined using 3 large-scale composition databases (OQALI, Open Food Facts, GNPD), accounting for the date of consumption of the product. Quantitative ingested doses were estimated using a combination of laboratory assays on food matrixes (n = 2677) and data from EFSA and JECFA. Exposure was estimated in mg per kg of body weight per day. Profiles of exposure to food additive mixtures were extracted using Non-negative Matrix Factorization (NMF) followed by k-means clustering as well as Graphical Lasso. Sociodemographic and dietary comparison of clusters of participants was performed by Chi-square tests or linear regressions. Data were weighted according to the national census. Forty-eight additives were consumed by more than 10% of the participants, with modified starches and citric acid consumed by more than 90%. The top 50 also included several food additives for which potential adverse health effects have been suggested by recent experimental studies: lecithins (86.6% consumers), mono- and diglycerides of fatty acids (78.1%), carrageenan (77.5%), sodium nitrite (73.9%), di-, tri- and polyphosphates (70.1%), potassium sorbate (65.8%), potassium metabisulphite (44.8%), acesulfame K (34.0%), cochineal (33.9%), potassium nitrate (31.6%), sulfite ammonia caramel (28.8%), bixin (19.5%), monosodium glutamate (15.1%) and sucralose (13.5%). We identified and described five clusters of participants more specifically exposed to five distinct additive mixtures and one additional cluster gathering participants with overall low additive exposure. Food additives, including several for which health concerns are currently debated, were widely consumed in this population-based study. Furthermore, main mixtures of additives were identified. Their health impact and potential cocktail effects should be explored in future epidemiological and experimental studies.

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.

Sulfites inhibit the growth of four species of beneficial gut bacteria at concentrations regarded as safe for food

Sulfites and other preservatives are considered food additives to limit bacterial contamination, and are generally regarded as safe for consumption by governmental regulatory agencies at concentrations up to 5000 parts per million (ppm). Consumption of bactericidal and bacteriostatic drugs have been shown to damage beneficial bacteria in the human gut and this damage has been associated with several diseases. In the present study, bactericidal and bacteriostatic effects of two common food preservatives, sodium bisulfite and sodium sulfite, were tested on four known beneficial bacterial species common as probiotics and members of the human gut microbiota. Lactobacillus species casei, plantarum and rhamnosus, and Streptococcus thermophilus were grown under optimal environmental conditions to achieve early log phase at start of experiments. Bacterial cultures were challenged with sulfite concentrations ranging between 10 and 3780 ppm for six hours. To establish a control, a culture of each species was inoculated into media containing no sulfite preservative. By two hours of exposure, a substantial decrease (or no increase) of cell numbers (based on OD₆₀₀ readings) were observed for all bacteria types, in concentrations of sulfites between 250–500 ppm, compared to cells in sulfite free media. Further testing using serial dilution and drop plates identified bactericidal effects in concentrations ranging between 1000–3780 ppm on all the Lactobacillus species by 4 hours of exposure and bactericidal effects on S. thermophilus in 2000ppm NaHSO₃ after 6 hours of exposure.

The hydrogen-storing microporous silica 'Microcluster' reduces acetaldehyde contained in a distilled spirit

Acetaldehyde is a detrimental substance produced in alcoholic liquor aging. We assessed an ability of hydrogen-storing microporous silica 'Microcluster' (MC+) to reduce acetaldehyde, as compared with autoclave-dehydrogenated MC+ (MC-). Acetaldehyde was quantified spectrophotometrically by an enzymatic method. Authentic acetaldehyde was treated by MC+ for 20min, and decreased from 43.4ppm to 10.9ppm, but maintained at 49.3ppm by MC-. On the other hand, acetaldehyde contained in a distilled spirit was decreased from 29.5ppm to 3.1ppm at 20min by MC+, but not decreased by MC-. Addition of MC+ or MC- to distilled water without acetaldehyde showed no seeming effect on the quantification used. Accordingly acetaldehyde in a distilled spirit is reduced to ethanol by hydrogen contained in MC+, but not by the silica moiety of MC+. Hydrogen gas of 1.2mL was released for 20min from MC+ of 0.59g in water, resulting in dissolved hydrogen of 1.09ppm and an oxidation- reduction potential of -687.0mV indicative of a marked reducing ability. Thus, MC+ has an ability to reduce acetaldehyde in a distilled spirit due to dissolved hydrogen released from MC+.

Sensitivity to food additives, vaso-active amines and salicylates: a review of the evidence

Although there is considerable literature pertaining to IgE and non IgE-mediated food allergy, there is a paucity of information on non-immune mediated reactions to foods, other than metabolic disorders such as lactose intolerance. Food additives and naturally occurring 'food chemicals' have long been reported as having the potential to provoke symptoms in those who are more sensitive to their effects. Diets low in 'food chemicals' gained prominence in the 1970s and 1980s, and their popularity remains, although the evidence of their efficacy is very limited. This review focuses on the available evidence for the role and likely adverse effects of both added and natural 'food chemicals' including benzoate, sulphite, monosodium glutamate, vaso-active or biogenic amines and salicylate. Studies assessing the efficacy of the restriction of these substances in the diet have mainly been undertaken in adults, but the paper will also touch on the use of such diets in children. The difficulty of reviewing the available evidence is that few of the studies have been controlled and, for many, considerable time has elapsed since their publication. Meanwhile dietary patterns and habits have changed hugely in the interim, so the conclusions may not be relevant for our current dietary norms. The conclusion of the review is that there may be some benefit in the removal of an additive or a group of foods high in natural food chemicals from the diet for a limited period for certain individuals, providing the diagnostic pathway is followed and the foods are reintroduced back into the diet to assess for the efficacy of removal. However diets involving the removal of multiple additives and food chemicals have the very great potential to lead to nutritional deficiency especially in the paediatric population. Any dietary intervention, whether for the purposes of diagnosis or management of food allergy or food intolerance, should be adapted to the individual's dietary habits and a suitably trained dietitian should ensure nutritional needs are met. Ultimately a healthy diet should be the aim for all patients presenting in the allergy clinic.

Dietary exposure to benzoates (E210-E213), parabens (E214-E219), nitrites (E249-E250), nitrates (E251-E252), BHA (E320), BHT (E321) and aspartame (E951) in children less than 3 years old in France

This study aimed to estimate the exposure to seven additives (benzoates, parabens, nitrites, nitrates, BHA, BHT and aspartame) in children aged less than 3 years old in France. A conservative approach, combining individual consumption data with maximum permitted levels, was carried out for all the additives. More refined estimates using occurrence data obtained from products' labels (collected by the French Observatory of Food Quality) were conducted for those additives that exceeded the acceptable daily intake (ADI). Information on additives' occurrence was obtained from the food labels. When the ADI was still exceeded, the exposure estimate was further refined using measured concentration data, if available. When using the maximum permitted level (MPL), the ADI was exceeded for benzoates (1.94 mg kg(-1) bw day(-1)), nitrites (0.09 mg kg(-1) bw day(-1)) and BHA (0.39 mg kg(-1) bw day(-1)) in 25%, 54% and 20% of the entire study population respectively. The main food contributors identified with this approach were current foods as these additives are not authorised in specific infant food: vegetable soups and broths for both benzoates and BHA, delicatessen and meat for nitrites. The exposure estimate was significantly reduced when using occurrence data, but in the upper-bound scenario the ADI was still exceeded significantly by the age group 13-36 months for benzoates (2%) and BHA (1%), and by the age group 7-12 months (16%) and 13-36 months (58%) for nitrites. Measured concentration data were available exclusively for nitrites and the results obtained using these data showed that the nitrites' intake was below the ADI for all the population considered in this study. These results suggest that refinement of exposure, based on the assessment of food levels, is needed to estimate the exposure of children to BHA and benzoates for which the risk of exceeding the ADI cannot be excluded when using occurrence data.

Survey of sulfites in wine and various Turkish food and food products intended for export, 2007-2010

Surveys were carried out between 2007 and 2010 to determine the total levels of sulfites in 1245 samples of wines, dried apricots, dried vegetables, nuts, juices and purees, frozen foods and cereals containing dried fruit supplied by food inspectors and by food producers for testing or for export certification. Sulfite analysis of wine was carried out using the Ripper method with an LOQ of 5 mg l(-1) and for dried and other foods the Monier-Williams distillation procedure was employed with an LOQ of 10 mg kg(-1). In the survey all wines contained measurable sulfites, but with the exception of one sample of white wine they were otherwise below Turkish Food Codex limits of 160 mg kg(-1) for red wine, 210 mg kg(-1) to white wine and 235 mg kg(-1) for sparkling wine. None of the cereal products, frozen foods, juices or purees contained sulfites above 10 mg kg(-1). However, all dried apricot samples contained significant levels of sulfite with around 40% having levels exceeding the Turkish limit of 2000 mg kg(-1). Significant levels of sulfite were found in other samples of dried fruit with even a fruit and nut bar containing 1395 mg kg(-1) of sulfite, suggesting the dried fruit ingredients contained levels above regulatory limits.

Estimate of dietary exposure to sulphites in child and adult populations in the Basque Country

Sulphites are widely used as a preservative and antioxidant additive in food. The aim of this study was to assess dietary sulphite intake in adults aged 35-65 years and in children aged 4-18 years living in the Basque Country, northern Spain. We determined sulphite concentrations in 909 samples covering 16 food types. The maximum permitted levels were exceeded in 17% of samples. Making recommended assumptions for non-quantifiable results, estimates of mean lower and upper bounds were calculated for sulphite concentrations in each food type. These sulphite data were combined with consumption data derived from 8417 adults from the European Prospective Investigation in Cancer and Nutrition cohort in Gipuzkoa, recruited in 1992-1995 using a diet history method, and 1055 children from the Basque Country Nutrition Children Survey, conducted in 2004-2005 using two 24-h recall questionnaires to assess diet. The results were compared with the acceptable daily intake (ADI) proposed by the Joint Expert Committee on Food Additives (JECFA). The mean dietary exposure to sulphites was 0.08 mg kg⁻¹ bw day⁻¹, only 11% of the ADI in the overall group of children (4-18 years old), but the acceptable intake was exceeded by 4% of 4-6 year olds. For the adults (35-65 years old), the mean dietary exposure was 0.31 mg kg⁻¹ bw day⁻¹, 45% of the ADI, but the acceptable intake was exceeded in 14.6% of cases. The major contributing foods were minced meat and other meat products for children and wine for adults.

Exposure assessment of food preservatives (sulphites, benzoic and sorbic acid) in Austria

An exposure assessment was performed to estimate the potential intake of preservatives in the Austrian population. Food consumption data of different population groups, such as preschool children aged 3-6 years, female and male adults aged 19-65 years were used for calculation. Levels of the preservatives in food were derived from analyses conducted from January 2007 to August 2010. Dietary intakes of the preservatives were estimated and compared to the respective acceptable daily intakes (ADIs). In the average-intake scenario, assuming that consumers randomly consume food products that do or do not contain food additives, estimated dietary intakes of all studied preservatives are well below the ADI for all population groups. Sulphite exposure accounted for 34%, 84% and 89% of the ADI in preschool children, females and males, respectively. The mean estimated daily intake of benzoic acid was 32% (preschool children), 31% (males) and 36% (females) of the ADI. Sorbic acid intakes correspond to 7% of the ADI in preschool children and 6% of the ADI in adults. In the high-intake scenario assuming that consumers always consume food products that contain additives and considering a kind of brand loyalty of consumers, the ADI is exceeded for sulphites among adults (119 and 124%, respectively). Major contributors to the total intake of sulphites were wine and dried fruits for adults. Mean estimated dietary intakes of benzoic acid exceeded the ADI in all population groups, 135% in preschool children, 124% in females and 118% of the ADI in males, respectively. Dietary intakes of sorbic acid are well below the ADI, accounting for a maximum of 30% of the ADI in preschool children. The highest contributors to benzoic and sorbic acid exposure were fish and fish products mainly caused by high consumption data of this large food group, including also mayonnaise-containing fish salads. Other important sources of sorbic acid were bread, buns and toast bread and fruit and vegetable juices.

Use of a membraneless extraction module for the voltammetric determination of total sulfites in wine

A recently developed membraneless extraction module (MLEM) for sample preparation aiming the analysis of volatile and semi-volatile compounds is applied in the voltammetric analysis of total sulfites in wine. Square-wave voltammetry (SWV) is very advantageous in this case because sulfur dioxide (SO2) is instrumentally directly detected. The developed method shows good repeatability (RSD lower than 5%) and linearity (between 20 to 220 mg l–1) as well as suitable limits of detection (6 mg l–1) and quantification (19 mg l–1). The proposed method was also compared with the reference methodology (an iodimetry, the Ripper method) showing no significant differences in the obtained results.

Dietary exposure of children and teenagers to benzoates, sulphites, butylhydroxyanisol (BHA) and butylhydroxytoluen (BHT) in Beirut (Lebanon)

The acceptable daily intake (ADI) for a considered chemical is by definition the amount of that substance which can be ingested every day during the life time without appreciable health risk. The theoretical risk of exceeding the ADI for benzoates, sulphites, butylhydroxyanisol (BHA) and butylhydroxytoluen (BHT) has often been examined on the basis of worst case scenario. The aim of this paper is to assess the actual intake of the food additives listed above for a group of the Lebanese population (students aged between 9 and 18 years old) likely to be highly exposed to food additives through the consumption of processed foods. Dietary exposure was obtained by combining food consumption data with food additives levels determined by chemical analysis. Food products available in Lebanon and containing added benzoates, sulphites, BHA and BHT were identified. Overall 420 samples of foods and beverages were analysed. The determination of food additives residue levels was carried out according to the official methods adopted in "Lebanese Institute for agronomic research" (IRAL) on food as consumed. The acceptable daily intake (ADI) could be exceeded for sulphites and BHT by a fraction of the population, in particular within children of 9-13 years old. Among all food additive-containing foods, the highest contributors were: soft drinks to benzoates intake, nuts and canned juices to sulphites intake, bread and biscuits to BHA intake and chewing gum to BHT intake.

Dietary exposure to chemicals within the process of risk assessment: possible applications to substances that may cause allergic reactions

Exposure assessment is one of the key parts of the risk assessment process. This task is crucial when evaluating substances for which only intake of toxicologically-important amounts can lead to adverse health effects. Ideally, dietary exposure to hazardous substances can be assessed by combining data on concentration in all food products with data on their consumption. However, it is considered to be neither cost-effective nor necessary to collect detailed data for every substance, and a stepwise procedure is commonly used to focus resources on the most important issues. Screening methods, designed to look for 'worst case' situations, are first used to target chemicals that might be of health concern for the general population or for certain at-risk groups. The quality of the dietary exposure assessments not only depends on the quality of the data collected, but also on the integration tools used for initial screening or for the eventual more precise estimations. A particular challenge is the evaluation of food allergens and components causing other forms of intolerances, since no reliable data seem to be currently available on the type of exposure (amounts and duration) required to induce a food allergy. A different approach from that used for dietary exposure to other hazardous substances has to be adopted. However, the methodologies (such as those used to collect food consumption data) and databases (in particular, information about food labels) developed in such a context could be useful to investigate the exposure conditions leading to the development of food allergies.

Estimate of dietary exposure to sulphites using Brazilian students as a sample population

In Brazil, there is neither a register of the use of sulphites by the food industry nor is research being undertaken on their dietary exposure to the population. The objective of the work reported here was to estimate the dietary exposure to sulphites in two different groups of high school students, a fee-paying school group and a state school group. The data were collected through a 24-hour dietary recall, which provided estimates of sulphited foods and beverages in the diet. The Maximum Permitted Level (MPL), established by the Brazilian legislation for each of the sulphited food and beverages, was used to measure the dietary exposure to this additive. On this basis none of the students could have exceeded the Acceptable Daily Intake (ADI) of 0.70 mg SO2/kg bw/day, with a average dietary exposure of 0.07 mg SO2/kg bw/day (p<0.001), with no significant statistical difference (p=0.643) between fee-paying and state school students. Highly exposed consumers (dietary exposure to more than 50% of the ADI, or either, 0.35 mg SO2/kg bw/day, to the maximum of 0.52 mg SO2/kg bw/dia) represented 4.5% of the researched samples and reached these levels of intake due to a consumption beyond 500 ml/day of industrialized packaged fruit juices, and, in the fee-paying school, for associating its consumption with alcoholic beverages like beer and wine.

Development of databases for use in validation studies of probabilistic models of dietary exposure to food chemicals and nutrients

The data currently available in the European Union in terms of food consumption and of food chemical and nutrient concentration data present many limitations when used for estimating intake. The most refined techniques currently available were used within the European Union FP5 Monte Carlo project to estimate, as accurately as possible, the intake of food additives, pesticide residues and nutrients. Databases of 'true' intakes of food additives (based on brand level food consumption records and additive concentration data), pesticide residues (based on duplicate diet studies) and nutrients (based on biomarker studies) have thus been generated. These kind of estimates are rarely repeatable because the databases generated and used to calculate them require an extraordinary expenditure of time and resources. The databases created served the purpose of estimating as accurately as possible 'true' chemical intakes for assessing the validity of additive, nutrient and pesticide probabilistic models.

Stochastic modelling of human exposure to food chemicals and nutrients within the "Montecarlo" project: an exploration of the influence of brand loyalty and market share on intake estimates of intense sweeteners from sugar-free soft drinks

To get a more realistic view of exposure to food chemicals, risk managers are getting more interested in stochastic modelling as an alternative to deterministic approaches based on conservative assumptions. It allows to take into account all the available information in the concentration of the chemical present in foods and in food consumption patterns. Within the EC-funded "Montecarlo" project, a comprehensive set of mathematical algorithms was developed to take into account all the necessary components for stochastic modelling of a variety of food chemicals, nutrients and ingredients. An appropriate computer software is being developed. Since the concentration of food chemicals may vary among different brands of the same product, consumer behaviour with respect to brands may have an impact on exposure assessments. Numeric experiments were carried out on different ways of incorporating indicators of market share and brand loyalty in the mathematical algorithms developed within the stochastic model of exposure to intense sweeteners from sugar-free beverages. The 95th percentiles of intake were shown to vary according to the inclusion/exclusion of these indicators. The market share should be included in the model especially if the market is not equitably distributed between brands. If brand loyalty data are not available, the model may be run under theoretical scenarios.