Gastrointestinal Bioaccessibility Research Articles

Bioaccessibility of plastic-related compounds from polymeric particles in marine settings: Are microplastics the principal vector of phthalate ester congeners and bisphenol A towards marine vertebrates?

Marine vertebrates are known to ingest significant amounts of microplastics (MPs). Once ingested, MPs might cause gastrointestinal injuries and serve as a path of harmful plastic components, such as phthalate esters (PAEs) and bisphenol A (BPA) in the food chain. However, there is a lack of standardized in-vitro methods capable of simulating fish uptake of chemicals from MPs in the environment as potential vectors of such contaminants. In this work, leaching and in-vitro oral bioaccessibility testing of PAEs and BPA from MPs were conducted batchwise using artificial seawater and gut fluids mimicking gastric, intestinal, and gastrointestinal compartments of marine vertebrates at physiological temperature. The environmental and physiologically relevant extraction tests were applied to medium-density polyethylene (PE) and polyvinyl chloride (PVC) certified reference materials containing eight PAEs of varying hydrophobicity, namely, dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate, benzylbutyl phthalate, diethylhexyl phthalate, di-n-octyl phthalate, diisononyl phthalate and diisodecyl phthalate, and BPA (only in PE) as MP surrogates with realistic analyte concentrations for primary MPs. The analysis of the leachates/gut fluid extracts was performed via dilute-and-shoot by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Only the most hydrophilic compounds, i.e. DMP, DEP and BPA, were found to get released significantly in saline waters, and exhibited the highest oral bioaccessibility rates (34–83 %). Based on our results, a dual-compartment physiologically relevant gastrointestinal test is recommended for appropriate estimation of fish bioaccessibility. The fish daily intakes of DMP, DEP and BPA from MPs, and seawater ingestion as well were estimated using several contamination scenarios (10th percentile as low level, 50th percentile as medium level and 90th percentile as high level contamination) based on probabilistic distributions and cumulative probability curves of measured environmental concentrations of (i) MP in seawater throughout the world, (ii) DMP, DEP and BPA in beached MP and those sampled in the open ocean (including both incurred and adsorbed contaminants), and (iii) DMP, DEP and BPA in seawater as reported in recent literature. Under a medium-level concentration scenario (50th percentile) in marine settings, and taking the gastrointestinal bioaccessibility factor into account, the daily intake of DMP, DEP and BPA from MPs accounted for a mere 0.02 % of the waterborne contribution. Hence, the ingestion of MPs should not be considered the primary route of fish exposure to BPA and the most polar PAEs in marine environments. However, more studies on the local and global scales using the continuously available data in the literature for mass concentrations of MP and additives in marine settings are needed for further confirmation of our findings.

Impact of In Vitro Gastrointestinal Digestion on the Phenolic Bioaccessibility and Bioactive Properties of Insect-Containing Beef Burgers.

Mealworm, migratory locust, and house cricket have recently been recognized by the European Commission as novel foods, thus being suitable in different food applications. In this work, we tested their powders as meat extenders at 5% (w/w) inclusion in beef burgers, considering their ability to vehicle phenolic compounds during simulated in vitro static gastrointestinal digestion (INFOGEST). Insect powders were abundant in different phenolic classes, recording the highest values in locust (LP; 314.69 mg/kg), followed by cricket (CP; 113.3 mg/kg) and mealworm (MWP; 51.9 mg/kg). Following a pan-cooking process, LP burgers were confirmed as the best source of phenolics, with a marked abundance of flavonoids and phenolic acids. Interestingly, the insect powders were found to affect the in vitro gastrointestinal bioaccessibility of phenolic compounds when compared with the CTR burger, likely promoted by the interactions between the phenolic compounds and proteins characterizing the tested insect powders. Among the most discriminant phenolic metabolites at the gastrointestinal level, we found several phenolic acids (mainly hydroxycinnamics), recording the highest content for the digested CP-containing burgers. Finally, stilbenes showed significant correlation values at the intestinal level with both antioxidant and enzymatic activities, while total flavonoids were the most correlated with the inhibition of acetylcholinesterase. Taken together, our preliminary findings demonstrated that insect powders added to beef burgers can promote the bioaccessibility and potential bioavailability of phenolics in the distal tracts of the intestine.

A novel bioaccessibility-based probabilistic risks assessment of potentially toxic elements (PTEs) in earthworm.

Introduction: Early risk assessment studies usually based on total heavy metal (loid) contents, inevitably leading to an overestimation of the health risks. In addition, inputs are represented as single-point estimates in deterministic models, leading to underestimation or overestimation of the health risks. Methods: To overcome these barriers, a novel probabilistic risk assessment strategy based on the combinational use of bioaccessibility and Monte Carlo simulation was developed to assess heavy metal (loid) associated health risks of earthworms in this study. To obtain a realistic and robust probabilistic risk assessment, heavy metal (loid) exposure duration and frequency were determined using our questionnaire data. Results: As a result, the mean gastrointestinal bioaccessibility was in the order: Cd > As > Cu > Hg. The mean hazard index (HI) values for investigated metal (loid)s were 0.65 and 0.59 for male and female, respectively, demonstrating an acceptable health risk in an average community. However, the 90th percentile of HI values was 1.87 and 1.65 for male and female, respectively. And the total non-cancer risks of heavy metal (loid) exposure exceeded the acceptable threshold for 19.9% and 17.8% of male and female, respectively. In addition, the total cancer risk (TCR) value through co-exposure to As and Cd suggested that the carcinogenic risks may be of concern for average exposure population. Sensitivity analyses revealed that the exposure frequency and bioaccessible As concentration were the dominant contributors to the total risk variance, which provided meaningful implications for environmental management. Conclusion: Altogether, the refined strategy based on bioaccessibility and Monte Carlo simulation is the first of its kind, such effort attempts to scientifically guide the rational clinic use of TCM and the improvement of population-health.

Investigating the Impact of Dietary Fibers on Mycotoxin Bioaccessibility during In Vitro Biscuit Digestion and Metabolites Identification.

Mycotoxins contamination is a real concern worldwide due to their high prevalence in foods and high toxicity; therefore, strategies that reduce their gastrointestinal bioaccessibility and absorption are of major relevance. The use of dietary fibers as binders of four mycotoxins (zearalenone (ZEA), deoxynivalenol (DON), HT-2, and T-2 toxins) to reduce their bioaccessibility was investigated by in vitro digestion of biscuits enriched with fibers. K-carrageenan is a promising fiber to reduce the bioaccessibility of ZEA, obtaining values lower than 20%, while with pectin a higher reduction of DON, HT-2, and T-2 (50-88%) was achieved. Three metabolites of mycotoxins were detected, of which the most important was T-2-triol, which was detected at higher levels compared to T-2. This work has demonstrated the advantages of incorporating dietary fibers into a biscuit recipe to reduce the bioaccessibility of mycotoxins and to obtain healthier biscuits than when a conventional recipe is performed due to its high content of fiber.

Fabrication of “Lysine modified Zein- Punica granatum peels’ purified ellagitannin nanoconjugates (Ly-M-Z-PE NCs)” and in-vitro bio-accessibility, antiproliferative activity, and biosafety studies

Pomegranate (punica garanatum) peels' ellagitannins exhibit remarkable health-beneficial properties. In the current work, lysine-modified, zein-based, pomegranate peels’ purified ellagitannin nanoconjugates were fabricated. The dynamic light scattering and field emission scanning electron microscopy findings demonstrated that pH (3, 5, 7, 9, and 11) has a significant effect on particle size, zeta potential, and shape of the nanoconjugates. It was found that a near-neutral pH (6.8–7) was ideal for fabricating the conjugated nanoparticles with reduced particle sizes (174.33 nm), homogeneous size distribution (0.1), and a good net charge (−25.53 mv). In these conditions, it demonstrated good particle production (83.83%) and binding effectiveness (83.23%) of total hydrolysable tannins. Transmission electron microscopy showed evenly dispersed spherical particles. Fourier transform infrared spectroscopy revealed conjugations between pure ellagitannins, and protein nanoparticles involving hydrogen bonding, hydrophobic interaction, and electrostatic contact. The synthesized nanoconjugates exhibited strong antioxidant scavenging capacity. Thermal stability, antibacterial activity, in vitro gastrointestinal bioaccessibility, and antiproliferative activity (liver cancer cells) were all improved by conjugation. The cytotoxic study of Lysine modified zein purified ellagitannin nanoconjugates showed no deleterious impact on normal Vero cell lines. Overall, our work shows that adding pure ellagitannin from pomegranate peels to protein nanoparticles is a cost-effective way to meet customer demand for safer, newer, healthier foods with better quality and uses.

Fibre enrichment of cookies to mitigate acrylamide formation and gastrointestinal bioaccessibility

Acrylamide (AA) is a food contaminant with serious health effects. In this work, the addition of dietary fibre was proposed to mitigate AA in cookies and to reduce bioaccesibility in the gastrointestinal trac. The analytical methodology applied for AA quantification was based on solid-liquid extraction (SLE) followed by gas chromatography (GC) coupled to mass spectrometry (MS). Preliminar results with commercial dietary fibres, such as k-carrageenan, arabinogalactan and pectin, indicated that the highest reduction of AA could be obtained with the addition of 5 g of pectin/100 g of flour to cookies recipe. Thus, different sources of pectin were evaluated: commercial pectin (CP) and three apple pomaces (dehydrated apple pomace (DP), sugar removed lyophilized apple pomace (SRL) and sugar removed lyophilized and powdered apple pomace (SRLP)). The highest AA mitigation was obtained with SRL and SRLP (62% and 48% of inhibition). After in vitro digestion, all sources of dietary fibres provided the lowest bioaccessibility results (13–46%) compared with control (>63%).

Gastrointestinal bioaccessibility and fiber mitigation of tropane alkaloids assessed on tea and cookies by in vitro digestion.

Tropane alkaloids (TAs) are toxic compounds with a high anticholinergic effect. They have been widely analyzed in food samples, but their fate in the gastrointestinal tract has not been evaluated yet. In the current study, static in vitro digestion was performed to assess gastrointestinal bioaccessibility of the most common TAs on tea and home-made cookies. Cookies enriched with dietary fibers (pectin, arabinogalactan and K-carrageenan) were also tested to evaluate their influence on TAs bioaccessibility. Two extraction methods and a liquid chromatography-mass spectrometry method were optimized and validated. Bioaccessibility for tea (60-105%) were higher than for cookies (39-93%) (p-values=0.001-0.002), which indicates TAs could be more easily absorbed when they are contaminating tea. Digestion of cookies enriched with 50 g kg-1 of different fibers showed that, although no significant changes were observed in the gastric phase (p-values=0.084-0.920), duodenal bioaccessibility was significantly reduced (p-values=0.008-0.039). Pectin was the fiber with a better mitigation effect for all the compounds. TAs bioaccessibility was determined after in vitro digestion of contaminated tea and cookies. Dietary fibers seem to be a promising mitigation strategy, significantly reducing the TAs bioaccessibility percentages. This article is protected by copyright. All rights reserved.

Bioaccessibility and reliable human health risk assessment of heavy metals in typical abandoned industrial sites of southeastern China

Heavy metal pollution caused by a large number of abandoned industrial sites cannot be underestimated, but its human health risks have not been accurately assessed. This study investigated the pollution of heavy metals in soils of the typical abandoned industrial sites in southeastern China. Based on the bioaccessibility of different heavy metals (Pb, Ni, Cu, Zn, Cd, Cr) in the industrial soils, the human health risks were accurately evaluated, and the controlling factors were quantitatively assessed. The results showed that the heavy metals in each typical abandoned industrial sites had a high degree of spatial heterogeneity. Among them, Cd was the most susceptible to relevant discrete input from external factors such as human activities, followed by Zn, Pb, Cr, Ni and Cu. The bioaccessible concentration of heavy metals by the physiological-based extraction test (PBET) had a good correlation (R2 = 0.58 ∼ 0.86) with its bioavailable concentration by diethylenetriaminepentaacetic acid (DTPA) extraction. The regression model based on soil parameters had great potential to predict the bioaccessibility of heavy metals in abandoned industrial sites (R2 = 0.49 ∼ 0.95). The total concentration of heavy metals, Fe, soil texture and pH were the controlling factors of the metal bioaccessibility. Compared with the total concentration, the hazard index (HI) and carcinogenic risk (CR) values calculated based on gastrointestinal bioaccessibility were decreased by 39.0∼77.9% and 68.2∼79.9% in adults, and 45.3∼88.0% and 73.9∼83.5% in children, respectively. This work provides a feasible theoretical basis for reliable assessment of the human health risks of heavy metals in the abandoned industrial sites in the future.

Changes in Arsenic Speciation in Wild Edible Fungi after Different Cooking Processes and Gastrointestinal Digestion.

Arsenic (As) is enriched in wild edible fungi, which is one of the main important sources of As in humans' diet. In this study, two wild edible fungi were employed for investigation: (1) Pleurotus citrinopileatusone, which contains a high content of inorganic As (iAs) and (2) Agaricus blazei Murill, which contains a high content of organic As. This study investigated the changes in As content and its speciation after different daily cooking methods. We found that the content of As in Pleurotus citrinipileatus and Agaricus blazei Murill reduced by soaking plus stir-frying by 55.4% and 72.9%, respectively. The As content in Pleurotus citrinipileatus and Agaricus blazei Murill decreased by 79.4% and 93.4%, respectively, after soaking plus boiling. The content of As speciation in dried wild edible fungi reduced significantly after different treatments. Among them, iAs decreased by 31.9~88.3%, and organic As decreased by 33.3~95.3%. This study also investigated the bioaccessibility of As in edible fungi after different cooking processes via an in-vitro physiologically based extraction test (PBET). The results showed that the bioaccessibility of As was relatively high if the edible fungi were uncooked, boiled, or stir-fried. The gastric (G) bioaccessibility of As ranged from 51.7% to 93.0% and the gastrointestinal (GI) bioaccessibility of As ranged from 63.5% to 98.1%. Meanwhile, the bioaccessibility of inorganic As was found to be as high as 94.6% to 151%, which indicates that further evaluation of the potential health risks of wild edible fungi is necessary.

Oral and gastrointestinal bioaccessibility of anthocyanins in fresh, frozen, and blended blueberries

Oral and gastrointestinal bioaccessibility of anthocyanins in fresh, frozen, and blended blueberries

In vitro bioaccessibility and uptake of β-carotene from encapsulated carotenoids from mango by-products in a coupled gastrointestinal digestion/Caco-2 cell model

β-carotene is a carotenoid with provitamin A activity and other health benefits, which needs to become bioavailable upon oral intake to exert its biological activity. A better understanding of its behaviour and stability in the gastrointestinal tract and means to increase its bioavailability are highly needed. Using an in vitro gastrointestinal digestion method coupled to an intestinal cell model, we explored the stability, gastrointestinal bioaccessibility and cellular uptake of β-carotene from microparticles containing carotenoid extracts derived from mango by-products. Three types of microparticles were tested: one with the carotenoid extract as such, one with added inulin and one with added fructooligosaccharides. Overall, β-carotene was relatively stable during the in vitro digestion, as total recoveries were above 68 %. Prebiotics in the encapsulating material, especially inulin, enhanced the bioaccessibility of β-carotene almost 2-fold compared to microparticles without prebiotics. Likewise, β-carotene bioaccessibility increased proportionally with bile salt concentrations during digestion. Yet, a bile salts level above 10 mM did not contribute markedly to β-carotene bioaccessibility of prebiotic containing microparticles. Cellular uptake experiments with non-filtered gastrointestinal digests yielded higher absolute levels of β-carotene taken up in the epithelial cells as compared to uptake assays with filtered digests. However, the proportional uptake of β-carotene was higher for filtered digests (24 – 31 %) than for non-filtered digests (2 – 8 %). Matrix-dependent carotenoid uptake was only visible in the unfiltered medium, thereby pointing to possible other cellular transport mechanisms of non-micellarized carotenoids, besides the concentration effect. Regardless of a filtration step, inulin-amended microparticles consistently resulted in a higher β-carotene uptake than regular microparticles or FOS-amended microparticles. In conclusion, encapsulation of carotenoid extracts from mango by-products displayed chemical stability and release of a bioaccessible β-carotene fraction upon gastrointestinal digestion. This indicates the potential of the microparticles to be incorporated into functional foods with provitamin A activity.

Utilization of Olive Pomace in Green Synthesis of Selenium Nanoparticles: Physico-Chemical Characterization, Bioaccessibility and Biocompatibility.

Olive pomace extract (OPE) was investigated as a potential surface modifier for the development of the green synthesis process of selenium nanoparticles (SeNPs). In order to evaluate them as potential nutraceuticals, the obtained nanosystems were characterized in terms of size distribution, shape, zeta potential, stability in different media, gastrointestinal bioaccessibility and biocompatibility. Systems with a unimodal size distribution of spherical particles were obtained, with average diameters ranging from 53.3 nm to 181.7 nm, depending on the type of coating agent used and the presence of OPE in the reaction mixture. The nanosystems were significantly affected by the gastrointestinal conditions. Bioaccessibility ranged from 33.57% to 56.93% and it was significantly increased by functionalization of with OPE. Biocompatibility was investigated in the HepG2 and Caco2 cell models, proving that they had significantly lower toxicity in comparison to sodium selenite. Significant differences were observed in cellular responses depending on the type of cells used, indicating differences in the mechanisms of toxicity induced by SeNPs. The obtained results provide new insight into the possibilities for the utilization of valuable food-waste extracts in the sustainable development of nanonutraceuticals.

Red palm oil Pickering emulsion with pectin yields improved in vitro beta carotene bioaccessibility and oil stability: Physicochemical characterization and shelf stability studies

Pickering emulsion of red palm oil (RPO) with pectin as stabilizer was optimized using response surface methodology (RSM). RSM parameters for final red palm oil pickering emulsion (RPE) were 3% pectin, 30% RPO, and homogenization speed of 24,000 rpm for 15 min. RPE was subjected to physicochemical characterizations, along with storage studies for 15 days. Microstructure imaging of RPE confirmed pickering emulsion formation. Droplet diameter and zeta potential of RPE were 1.779 μm and −32.5 mV, respectively. Fourier transform infrared spectroscopy of RPE suggested hydrogen bonding interactions between the components, and thermogravimetric analysis revealed stability up to 40°C. Gastrointestinal bioaccessibility of naturally occurring β-carotene in the RPE (37.76 ± 1.2%) was found to be four times higher than that of RPO (8.7 ± 0.8%). The RPE was more stable at 4°C as indicated by storage analyses. RPE can improve the bioaccessibility of nutritionally important bioactive compounds. Practical applications Pickering emulsions of RPO stabilized by pectin can be used for developing functional foods with improved bioaccessibility of lipophilic bioactives such as carotenoids as well as for the delivery of temperature sensitive nutritional and bioactive compounds. These emulsions can also be found applications in beverages, low temperature processed foods and vegan fat substitutes.

Metal(loid) concentrations, bioaccessibility and stable lead isotopes in soils and vegetables from urban community gardens

Community gardens are “green oases” of recent cities with many benefits for human society. From a human health perspective, these benefits can be damaged by chemical contamination of soil and cultivated vegetables. Using geochemical approaches, this study characterised (i) total metal(loid) concentrations in soils and two commonly grown vegetables in urban community gardens (Bratislava, Slovakia), (ii) gastrointestinal bioaccessibility using a modified physiologically based extraction test (PBET), and (iii) stable lead (Pb) isotopes in order to identify sources of metal(loid)s, solubilisation in the human body and migration of Pb from soil to vegetables. While some soils could be considered contaminated when compared to the Slovak legislation for agricultural soil, the bioaccessibility of metal(loid)s did not exceed 20% in the intestinal phase, with the exception of cadmium (Cd). Tomatoes and lettuce contained low total and bioaccessible concentrations of metal(loid)s, being safe for people who consume their own grown vegetables. There were differences in Pb isotope composition among bulk soils, vegetables and bioaccessible Pb, with less radiogenic Pb being preferentially mobilised. Statistical methods considering the compositional nature of the geochemical data and the enrichment factor (EF) distinguished well metal(loid)s of natural origin (As, Co, Cr, Fe, Mn, Ni, V) from those with anthropogenic contributions. This research has shown the usefulness of integrating different methodologies to better understand the geochemistry of metal(loid)s in urban soils with their highly diversified sources.

Relative Contribution of Metal Content and Soil Particle Mass to Health Risk of Chromium-Contaminated Soil.

Three soil samples from a chromium (Cr)-contaminated field were classified into five particle fractions (i.e., 0–50 μm, 50–100 μm, 100–250 μm, 250–500 μm, and 500–1000 μm) and were further characterized to study their physicochemical properties and Cr bioaccessibility. The results indicated that the gastrointestinal bioaccessibility estimated by the Solubility Bioaccessibility Research Consortium (SBRC) method was on average 15.9% higher than that by the physiologically based extraction test (PBET) method. The health risk of all samples was within the safe range, and the health risk based on total Cr content may be overestimated by an average of 13.2 times compared to the bioaccessibility-based health risk. The health risk investigated from metal content was mainly contributed by the 50–250 μm fraction, which was 47.5, 50.2, and 43.5% for low-, medium-, and high-level polluted soils, respectively. As for the combined effect, the fractions of 100–250 μm and 500–1000 μm contributed the highest proportion to health risk, which was 57.1, 62.1, and 64.4% for low-level, medium-level, and high-level polluted soils, respectively. These results may further deepen the understanding of health risk assessment and quantify the contribution of the soil particle mass to health risk.

Cooking and In Vitro Digestion Modulate the Anti-Diabetic Properties of Red-Skinned Onion and Dark Purple Eggplant Phenolic Compounds.

The intake of phenolic-rich foods is an emerging preventive approach for the management of type 2 diabetes, thanks to the ability of these compounds to inhibit some key metabolic enzymes. In this study, the influence of cooking and in vitro digestion on the α-glucosidase, α-amylase, and dipeptidyl-peptidase IV (DPP-IV) inhibitory activity of red-skinned onion (RSO) and dark purple eggplant (DPE) phenolic fractions was assessed. The applied cooking procedures had different influences on the total and individual phenolic compounds gastrointestinal bioaccessibility. DPE in vitro digested phenolic fractions displayed no inhibitory activity versus α-amylase and DPP-IV, whereas the fried DPE sample exhibited moderate inhibitory activity against α-glucosidase. This sample mainly contained hydroxycinnamic acid amides that can be responsible for the observed effect. Contrariwise, raw and cooked in vitro digested RSO phenolic fractions inhibited all three enzymes but with different effectiveness. Fried and raw RSO samples were the most active against them. Statistical analysis pointed out that quercetin mono-hexosides (mainly quercetin-4′-O-hexoside) were responsible for the inhibition of α-glucosidase, whereas quercetin di-hexosides (mainly quercetin-3-O-hexoside-4′-O-hexoside) were responsible for the DPP-IV-inhibitory activity of RSO samples. An accurate design of the cooking methods could be essential to maximize the release of individual phenolic compounds and the related bioactivities.

Mimicking human ingestion of microplastics: Oral bioaccessibility tests of bisphenol A and phthalate esters under fed and fasted states

Notwithstanding the fact that microplastic fragments were encountered in the human stool, little effort has been geared towards elucidating the impact of chemical additives upon the human health. In this work, standardized bioaccessibility tests under both fasting and fed conditions are herein applied to the investigation of human oral bioaccessibility of plastic additives and monomers (i.e. eight phthalate esters (PAEs) and bisphenol A (BPA)) in low-density polyethylene (LDPE) and polyvinyl chloride (PVC) microplastics. The generation of phthalate monoesters is evaluated in the time course of the bioaccessibility tests. Maximum gastric and gastrointestinal bioaccessibility fractions are obtained for dimethyl phthalate, diethyl phthalate and BPA, within the range of 55–83%, 40–68% and 37–67%, respectively, increasing to 56–92% and 41–70% for dimethyl phthalate and diethyl phthalate, respectively, whenever their hydrolysis products are considered. Bioaccessibility fractions of polar PAEs are dependent upon the physicochemical characteristics of the microplastics, with greater bioaccessibility for the rubbery polymer (LDPE). With the method herein proposed, oral bioaccessible pools of moderately to non-polar PAEs can be also accurately assessed for risk-assessment explorations, with values ranging from 1.8% to 32.2%, with again significantly larger desorption percentages for LDPE. Our results suggested that the highest gastric/gastrointestinal bioaccessibility of the eight PAEs and BPA is reached under fed-state gastrointestinal extraction conditions because of the larger amounts of surface-active biomolecules. Even including the bioaccessibility factor within human risk assessment/exposure studies to microplastics, concentrations of dimethyl phthalate, di-n-butyl phthalate and BPA exceeding 0.3% (w/w) may pose severe risks after oral uptake in contrast to the more hydrophobic congeners for which concentrations above 3% (w/w), except for diethylhexyl phthalate, would be tolerated.

In vitro gastrointestinal bioaccessibility and colonic fermentation of lignans from fresh, fermented, and germinated flaxseed.

This research assessed the influence of fermentation and germination as well as of particle size on lignan bioaccessibility from flaxseed by simulated in vitro gastrointestinal digestion. In vitro simulated colonic fermentation was used to study lignan release and its conversion into enterolignans. In addition, tea was included as a representative sample to investigate the stability of lignans in the gastrointestinal tract. Only secoisolariciresinol (SECO) was detected in flaxseed samples. SECO bioaccessibility in fermented flaxseed was highest among all matrices but limited to ≈1% (P < 0.001). Lignan bioaccessibility was significantly influenced by particle size too (P < 0.001 for both). In the colon, fermented flaxseed produced the highest SECO release among all flaxseed samples (≈65%), and the highest conversion of enterolignan (≈1.0%), whereas the conversion of lignans in tea brew was relatively high (≈15%). Lignan conversion varies greatly among donors due to inter-individual differences in microbiota activity. Food fermentation could be a viable strategy for increasing lignan release and conversion to enterolignan.

Child risk assessment of selected metal(loid)s from urban soils using in vitro UBM procedure

In city agglomerations significant pollution results from fossil fuel combustion from heat and power plants, transportation, and boilers in households. In this context, pollution from recalcitrant, environmentally accumulative metal(loid)s can be a critical human health risk. In day-care centers, playgrounds, kindergartens, schools, and sport facility areas children may ingest significant quantities of potentially polluted soil and dust, increasing incidence of health disorders or diseases. The objective of this study was to assess the oral bioaccessibility and human health risk of As, Cd, Pb, Cr, Ni, Cu, and Zn from potentially polluted urban topsoils by applying gastrointestinal Unified Bioaccessibility Method (UBM) protocol. Total content of studied elements was relatively low and none of studied elements exceeded Polish legal limits for urban soils. According to the Enrichment Factor (EF), studied sites were characterized from minimal to significant degrees of soil pollution by analyzed metal(loid)s in the order: Pb > Zn > Cu > Cd > As > Ni > Cr. Concentrations of the metal(loid)s in bioaccessible phases were varied, and higher for gastric than gastrointestinal bioaccessibility. Metal(loid) bioaccessibility in soils of Bydgoszcz was highly correlated with total concentration. Almost no correlation was found between concentration of these phases and parameters like soil pH, texture, CaCO3, TOC, or CEC. A relationship did exist with landform where the lower positions had greater concentrations. These locations are those with the highest traffic density and operation of old coal heating systems leading to the highest deposition of airborne contaminants. Higher landscape positions are favored for new facilities in newer residential districts. Exposure and health risk from soil ingestion given normal ingestion scenario at any site investigated was very low. Non-carcinogenic and carcinogenic risk was identified only for soil pica behavior. Soil pica ingestion scenario might be considered for children with lapses of adult.

Gastrointestinal bioaccessibility and bioactivity of phenolic compounds from araçá-boi fruit

In this study, we evaluated for the first time the bioaccessibility and bioactivity of phenolic compounds present in fractions of araçá-boi submitted to the in vitro gastrointestinal digestion. For this, were determined the content of phenolics and total flavonoids, antioxidant capacity, as well as heatmap analysis to evaluate the relative intensity of the phenolic compounds identified by ESI-LTQ-XL-MS/MS, before and after digestive process. It was observed that the seed had the highest amount of total phenolic compounds, and that this content was reduced after digestion, mainly in the intestinal phase (-22.0%), while the flavonoid content increased in the edible fraction (92.8%). From the ESI-LTQXL-MS/MS analysis, it was possible to identify 9 flavonoids and 8 phenolic acids in the edible fraction, while in the seed 10 flavonoids and 7 phenolic acids were identified. Heatmap analysis demonstrated that after intestinal digestion, phenolic acids reduced and flavonoids increased their relative intensity, suggesting that these compounds increased their content after this process. The seed showed the highest antioxidant capacity and in general this potential increased after digestion. Thus, the bioaccessibility and bioactivity of the phenolic compounds of araçá-boi can be influenced by the fraction and digestive phase evaluated.