The influence of Lactobacillus plantarum fermentation in selenium-enriched Brassica napus L.:changes in the nutritional constituents,bioactivities and bioaccessibility

Selenium(Se)-enriched Brassica napus L.is a valuable organic Se supplement.In this study,the fermentation broth enriched with organic Se(FFS)was prepared using Lactobacillus plantarum to ferment the substrate of Se-enriched Brassica napus L.Significant increases were observed after fermentation in total sugars,reducing sugars,soluble proteins,total phenolic content(TPC),and total flavonoid content(TFC).The organic Se was retained at a concentration of 54.75 mg/g in the freeze-dried sample.Principal component analysis and cluster analysis showed good separation between the FFS and unfermented(FS)groups.Fragrant 2-ethyloxetane had the highest content among all volatiles,while sinapine had the highest content among all phenolic compounds.The fermentation process showed remarkable improvement in the abundance and concentration of volatile compounds and phenolic contents,making FFS exhibit strong antioxidant activity and inhibitory capacity againstα-glucosidase activity.The bioaccessibility of phenolic compounds was significantly greater in FFS compared to FS.ADMET analysis revealed that the majority of phenolic compounds contained in FFS did not exhibit mutagenicity toxicity,hepatotoxicity,skin sensitization,or blood-brain barrier penetration,indicating a favorable level of biosafety.Overall,our study provides a new insight into the further utilization of Se-enriched Brassica napus L.in foods.

Bioaccessibility of Vanadium from Soil and Mineral Measured by in vitro Model

[Objective] This study aimed to investigate the existing forms and bioaccessibility of vanadium（V） from soil and mineral of Panzhihua region.[Method] The representative Xigeda soil and vanadium-titanium magnetite were collected from Panzhihua region to determine the existing forms of vanadium from soil and mineral;in vitro bionic digestion model was established to measure the bioaccessibility of vanadium.[Result] The dissolved concentrations of vanadium from farmland,mining area and vanadium-titanium magnetite in gastric juice were respectively 5.02,9.50 and 3.88 mg/kg,and the bioaccessibility ranged from 0.09% to 3.00%;the dissolved concentrations of vanadium in intestinal juice were respectively 2.98,5.43 and 4.49 mg/kg,and the bioaccessibility ranged from 0.10% to 1.78%.The content of vanadium in various existing forms varied significantly,the contents of vanadium in non-specific adsorption state and specific adsorption state were low,but residual content was completely high,which accounted for 75.06%,95.32% and 86.27% of the total content of vanadium in samples.[Conclusion] Bioaccessibility of dissolved vanadium in gastric juice was higher than that in small intestinal juice.Vanadium from soil and mineral was difficult to generate morphological transformation and migration,which was the main reason for low bioaccessibility.

The Application of Nutrimetabolomics to Investigating the Bioaccessibility of Nutrients in Ham Using a Batch <i>in Vitro</i>Digestion Model

Delivering high quality dietary protein at an affordable price is a major aim of the EU-funded CHANCE project. Foods have been formulated with this aim and as part of their nutritional assessment;the bioaccessbility of nutrients following simulated gastroduodenal digestion is being investigated. Nutrimetabolomics approaches can be used to comprehensively and quantitatively analyse nutrients and metabolites. They have been applied to monitor nutrient release from ham, formulated in the CHANCE project, during in vitro digestion. SDS-PAGE analysis shows that constituent ham proteins were broken down to lower molecular weight polypeptides (Mr ≤ 10 kDa) after 120 min simulated gastric digestion which was digested further by subsequent duodenal digestion. Digestion of porteins resulted in the appearance of coalesced lipid droplets associated with the loss of the muscle protein matrix of the ham. Important nutrients, such as choline, creatine, carnosine, sucrose, cholesterol, triacylglyceride and fatty acids (saturated and unsaturated) were identified using 1H NMR. Chance ham is a good source of dietary protein and the combined approach can provide representative data on the bioaccessibility of all detectable nutrients contained in CHANCE ham to human digestive system.

Characterization and Bioaccessibility of Minerals in Seeds of Salvia hispanica L.

Salvia hispanica L. is a herbacia plant that originates from Mexico and Guatemala, and it is currently known by the popular name of chia. Currently, chia seeds have been considered to be of great importance for human health and nutrition because they have a high concentration of polyunsaturated fatty acids. They contain the largest known percentage of fatty α-linolenic acid (ALA) in plants—approximately 68%. Furthermore, they are an excellent source of protein, dietary fiber, calcium, magnesium, iron, vitamin B and phenolic compounds that have antioxidant properties. However, despite the high nutritional value present in the food and the possible health benefits of its nutrients, there is a need to evaluate the bioaccessibility of its micronutrients to measure their effectiveness. Thus, we evaluated the chemical composition of chia seeds from different producers, their lipid profiles and the bioaccessibility of some of their minerals.

Antioxidant Capacity and Bioaccessibility of Synergic Mango (cv. Ataulfo) Peel Phenolic Compounds in Edible Coatings Applied to Fresh-Cut Papaya

Edible coatings (EC) applied to fresh-cut fruits are used to increase their shelf-life and to deliver antioxidant bioactives such as phenolic compounds (PC) that reduce their oxidative damage while enhance their functional value. However, the combination of different PC may have synergetic, additive or antagonic effects on the final antioxidant capacity (AOXC). The aim of this study was to examine the AOXC of binary combinations of selected PC from mango peel and their bioaccessibility from 6% alginate-based EC applied to fresh-cut papaya, under simulated gastrointestinal conditions. Among equimolar (0.1 mM) combinations, gallic + protocatechuic acids (AB) were synergic in radical scavenging activity (RSA) as assayed by DPPH (90% RSA) and FRAP (0.39 mg TE/mL) methods;when assayed in 6% alginate-based EC, their RSA increased (117.85% RSA, 0.88 mg TE/mL). The application of EC + AB to papaya cubes and further in vitro digestion decreased their AOXC probably due to interactions between EC and papaya’s matrix. Therefore, further studies are needed in order to evaluate the effect of combination of phenolic and EC applied in other fruits matrix on antioxidants bioaccessibility.

Inhalation Bioaccessibility of Potentially Toxic Metals in Tobacco Snuff and Related Exposure Risks

This study determined the concentrations and inhalation bioaccessibility of cadmium, chromium, nickel and zinc in some foreign and locally available tobacco snuff and leaves. For the determination of the heavy metals concentration, the samples were ashed and washed with hydrochloric acid according to standard method. The bioaccessibility test employed the Stimulated Epithelial Lung Fluid (SELF). The total concentration of heavy metals in the four samples investigated ranged between 9.7 - 14.9 μg/g, 24.1 - 37.0 μg/g, 41 - 69 μg/g and 153 - 183 μg/g for cadmium, chromium, nickel and zinc respectively. The percentage inhalation bioaccessibility fraction of the four samples investigated ranged between 20.8% - 59.8%, 3.3% - 8.1%, 21.7% - 48.8% and 7.6% - 12.5% for cadmium, chromium, nickel, and zinc respectively. Statistical analyses using SPSS 21, revealed significant differences in the total concentration of heavy metals in the samples investigated except for Zinc. Risk assessment based on daily consumption of 10 g of the tobacco snuff employing total concentration of the heavy metals suggests that excluding nickel, all other metals investigated indicated daily intake values above WHO permissible levels. However, with the bioaccessible fractions, only cadmium, a known carcinogen indicated levels above WHO limits. From the results of this study, it can be deduced that consumption of tobacco snuff may induce negative health effects such as cancer and its attendant complications, the risk analysis based on bioaccessible concentration suggests lower health risk than analysis based on total heavy metal concentration;hence the assumption that snuff is a safe alternative to tobacco smoking may be erroneous.

Bioaccessibility of Phenolic Compounds of Araucaria angustifolia from Seed Water Extracts during In Vitro Simulated Gastrointestinal Conditions

Food by-products containing bioactive substances, such as phenolic compounds, have garnered attention due to the possibility to increase the value of what would otherwise be considered residue. The present work sought to evaluate the extraction of phenolic compounds and their bioaccessibility from pinh&atilde;o “comum” (Araucaria angustifolia var. angustifolia) and pinh&atilde;o “macaco” (Araucaria angustifolia var. indehiscens) cooking water extracts during in vitro simulated gastrointestinal conditions. Our findings indicate that changes occurred depending on the type of extract and the gastrointestinal step. Although both of the evaluated pinh&atilde;o extracts displayed bioaccessible phenolic compounds, the gradual bioaccessibility decrease of pinh&atilde;o “macaco” extract during in vitro simulated gastrointestinal condition steps, characterizes this extract as the one with the best functional property. The functional property is related to antioxidant properties which are able to generate protective effects against various diseases.

Steam disinfection enhances bioaccessibility of metallic nanoparticles in nano-enabled silicone-rubber baby bottle teats,pacifiers,and teethers

Nano-enabled silicone-rubber articles for feeding or chewing could be a source of metallic nanoparticles(NPs)directly exposed to infants and young children.However,the impact of steam disinfection on release of NPs and the related potential risks to children's health are unknown.Here,we investigated contents and form of Ag and Zn in 57 nano-enabled silicone-rubber baby bottle teats,pacifiers,and teethers of seven countries and examined the impacts of steam disinfection on in vitro bioaccessibility(IVBA)of Ag and Zn in the articles.Nearly 89%articles had a mixture of Ag-and Zn-containing NPs and the teethers had relatively high Ag and Zn contents(up to 501 and 254μg/g,respectively).Steam disinfection caused rubber decomposition into micro(nano)plastics(0.54-15.7μm)and NP release from the interior of bulk rubber and micro-sized plastics,thus enhancing the IVBA of Ag and Zn by up to 5.5 times.The findings provide insights into mechanisms for NP release by steam disinfection.Though oral exposure risk assessment suggested low health concerns on individual metal release,our study points out the need to assess the potential health risks of child co-exposure to metallic NPs and micro(nano)plastics.

Predicting the Bioaccessibility of Soil Cd,Pb,and As with Advanced Machine Learning for Continental-Scale Soil Environmental Criteria Determination in China

Investigating the bioaccessibility of harmful inorganic elements in soil is crucial for understanding their behavior in the environment and accurately assessing the environmental risks associated with soil.Traditional batch experimental methods and linear models,however,are time-consuming and often fall short in precisely quantifying bioaccessibility.In this study,using 937 data points gathered from 56 journal articles,we developed machine learning models for three harmful inorganic elements,namely,Cd,Pb,and As.After thorough analysis,the model optimized through a boosting ensemble strategy demonstrated the best performance,with an average R2 of 0.95 and an RMSE of 0.25.We further employed SHAP values in conjunction with quantitative analysis to identify the key features that influence bioaccessibility.By utilizing the developed integrated models,we carried out predictions for 3002 data points across China,clarifying the bioaccessibility of cadmium(Cd),lead(Pb),and arsenic(As)in the soils of various sites and constructed a comprehensive spatial distribution map of China using the inverse distance weighting(IDW)interpolation method.Based on these findings,we further derived the soil environmental standards for metallurgical sites in China.Our observations from the collected data indicate a reduction in the number of sites exceeding the standard levels for Cd,Pb,and As in mining/smelting sites from 5,58,and 14 to 1,24,and 7,respectively.This research offers a precise and scientific approach for cross-regional risk assessment at the continental scale and lays a solid foundation for soil environmental management.

Speciation and bioaccessibility of lead and cadmium in soil treated with metal-enriched Indian mustard leaves

Indian mustard （Brassica juncea （L.） Czern.） has shown good potential for the phytoremediation of soil contaminated with heavy metals. However, there is little information about the speciation and bioaccessibility of heavy metals in soil during the decomposition of metal-rich Indian mustard leaves. Incubation experiments （1-, 3-, and 6-month） were carried out in Beijing and Hunan soil with metal-rich Indian mustard leaves addition （1% and 3%） and the effects of mustard leaves addition on the speciation and bioaccessibility of heavy metals were studied. The results showed that the addition of mustard leaves led to significant increases in pH and DOC in the Hunan soil. Both 1% and 3% of mustard leaf amendment caused the percentage of the exchangeable （F1）, precipitated with carbonates （F2）, bound to Fe/Mn oxides （F3） and bound to organic matter （F4） fractions of Pb and Cd to increase dramatically, while the percentage of the residual fraction （F5） of Cd and Pb significantly dropped in both Beijing and Hunan soils. Mustard leaf addition caused the bioaccessibility of Pb to decrease in the gastric phase, whereas the values increased in the small intestinal phase. The Cd bioaccessibility increased with mustard leaf addition in both the gastric and small intestinal phases. In conclusion, the metal-enriched mustard leaves addition induces Pb and Cd concentrations and their mobility increasing in the Beijing and Hunan soils. Therefore, heavy metal risk in metal-enriched plant leaves should be considered in phytoremediation system in which heavy metal might be brought back to soil and changed over time.

Comparison of in vitro digestion methods for determining bioaccessibility of Hg in rice of China

Rice consumption can be a major pathway for mercury（Hg） exposure, which can cause health hazards to Chinese residents. To accurately assess the potential health risks, the bioaccessibility of Hg in rice samples collected at background and Hg-contamination sites was examined using four in vitro methods. The results showed that 〈 50% of the total mercury（THg） was bioaccessible in the studied rice samples. The THg bioaccessibility in the rice samples collected at the Hg-contaminated site was higher than that observed at the background area. The bioaccessibility of arsenic（As） and cadmium（Cd） was also evaluated for comparison of the four in vitro methods used in this study. The Physiologically Based Extraction Test was found to be the most accurate method based on the consistency of the results compared to those reported in previous studies. The estimated daily intakes of THg via rice consumption using the bioaccessibility data were found to meet the recommendation value set by the JECFA and the WHO in both sites. However, the potential health risk was not negligible at the Hg-contaminated sites, due to the high THg concentration and bioaccessibility in the rice samples.

Assessing the factors impacting the bioaccessibility of mercury(Hg) in rice consumption by an in-vitro method

Mercury(Hg) in rice is drawing mounting concern since methylmercury(MeHg) was found capable of accumulating in rice. In-vitro bioaccessibility is a feasible and reliable method to assess the health effects of Hg in rice and has been utilized in a number of studies. This study was done to investigate the impact of cultivar, planting location, and cooking on the total mercury(THg) and MeHg bioaccessibility of rice, for which multiple statistical analysis methods were used to analyze the significance of their effects. The THg concentrations of rice samples taken from non-Hg contaminated areas of China were all below 15 ng/g and their MeHg concentrations were below 2 ng/g. Cooking could significantly reduce the MeHg bioaccessibility of rice because the MeHg was mainly combined with protein and the protein will be denatured during the cooking process, and then the denatured MeHg is difficult to be dissolved into the liquid phase. Indica-and japonica-type rice cultivars did not show significant differentiation in either the concentration of Hg or its bioaccessibility. However, the glutinous rice type differed significantly from the above rice types, and it showed greater bioaccessibility of THg and MeHg due to its distinct protein contents and starch properties. Planting location can affect the Hg concentration in rice and THg bioaccessibility but has a limited impact on MeHg bioaccessibility. Based on these results, two macro factors(rice cultivar, planting location) are presumed to impact Hg bioaccessibility by how they affect micro factors(i.e., Hg forms).

Gastrointestinal digestive fate of whey protein isolate coated liposomes loading astaxanthin:Lipolysis,release,and bioaccessibility

Whey protein isolate coated astaxanthin-loaded liposomes were prepared in this work.The gastrointestinal digestive fate of whey protein isolate coated astaxanthin-loaded liposomes was evaluated in terms of particle size,size distribution,zeta potential,and morphology during in vitro digestion as a function of time.Analysis on the particle size and morphology of whey protein isolate coated astaxanthin-loaded liposomes showed that the majority of particles maintained spherical shape with a progressive increase of particle size after passage through the digestion.The zeta potential on whey protein isolate coated astaxanthin-loaded liposomes became highly negative after digestion.As compared in uncoated liposomes,the astaxanthin release in whey protein isolate coated liposomes was slower in simulated gastric fluid digestion,while was faster in simulated intestinal fluid digestion.Through in vitro digestion,the bioaccessibility of astaxanthin was improved significantly after whey protein isolate coating.It was also found that the whey protein isolate coating could protect liposomes against destruction and suppress the lateral mobility of pyrene,resulting in lower micropolarity and fluidity of liposomal membrane during the digestion.These findings may guide the potential application of whey protein isolate coated liposomes for improving the bioaccessibility and stability of astaxanthin in nutraceuticals and pharmaceutics.

The impact of simulated gastrointestinal digestion on the bioaccessibility and antioxidant activity of purple rice phenolic compounds

Polyphenol-rich purple rice has been shown to exhibit a wide range of health properties including antioxidant activity.This study aimed to determine the impact that gastrointestinal digestion of purple rice had on its phenolic bioaccessibility and antioxidant activity.Our results demonstrated a significant difference(p<0.01)in bioaccessible phenolic content level and antioxidant activity between simulated gastric and intestinal digestion.However,mass spectrometry and ultra-high-performance liquid chromatography(UHPLC)coupled with online ABTS•+scavenging activity demonstrated a significant loss in the number of polyphenols that were bioaccessible after digestion.Interestingly,substantial free radical scavenging activity was retained after digestion due to the bioaccessibility of bioactive compounds such as tryptophan and protocatechuic acid.Hence,purple rice may be considered as a source of bioaccessible phenolic and antioxidant compounds.

Optimization of an in vitro method to measure the bioaccessibility of polybrominated diphenyl ethers in dust using response surface methodology

To more reasonably evaluate human intake of PBDEs via dust ingestion, bioaccessibility should be taken into account. Previously, we developed an in vitro method to determine the bioaccessibility of PBDEs in food. Here, this method was adapted to determine the bioaccessibility of PBDEs in dust and the digestion conditions that influenced the bioaccessibility of PBDEs were optimized. The digestion conditions included the incubation time of dust in the intestinal digestion solution （T）, the bile concentration in the intestinal digestion solution （Chile）, and the ratio of the volume of the intestinal digestion solution to dust （R）. The influence of the concentrations of individual PBDE congeners （CpBDE） on the bioaccessibility of PBDEs was also investigated. Cetral composite design was used to build an experimental model and set experimental parameters, and response surface methodology was used to analyze the obtained data. The results showed that the bioaccessibility of PBDEs increased with the increases of Chile and R, and was independent of T and CpSDE. Under the digestion conditions with Chile and R being at 4.0-7.0 g/L and 150-250, respectively, the bioaccessibility of PBDEs in the method-dust varied from 39.2% to 72.8%, which were comparable with the bioaccessibility or bioavailability of PBDEs in dust/soil in the literature. Thus, the in vitro method to measure the bioaccessibility of PBDEs in dust was established and validated. Finally, the bioaccessibility of PBDEs in four natural dust samples, which ranged from 36.1% to 43.3%, were determined using the adapted method.

Estimation of bioaccessibility and potential human health risk of mercury in Chinese patent medicines

Mercury（Hg）, mainly in cinnabar species, has been used in medicine for thousands of years in China, and worldwide concern has been raised on its toxicity. In this work, the amount of bioaccessible mercury in 16 Chinese patent medicines（CPMs） was measured by using an in vitro simulated digestion system, consisting of simulated gastric and intestinal fluid, to investigate the bioavailability of mercury in CPMs and evaluate its potential risk to human health. Total mercury and mercury in the gastrointestinal extracts were measured by inductively coupled plasma mass spectrometry（ICP-MS）. The levels of total Hg in 16 CPMs ranged from not detected to 11.89 mg/g, with a mean value of 1.13 mg/g, while the extractable Hg ranged from not detected to 4.37 μg/g, with a mean value of 0.42 μg/g.Mercury bioaccessibility varied significantly in the investigated CPMs, depending on the ingredient. Compared to the CPMs without cinnabar（2.5%–30.9%）, the percentage of mercury in the gastrointestinal supernatants for CPMs with cinnabar was quite a bit lower（0.037%）. By comparing with the Food and Agricultural Organization/World Health Organization Joint Expert Committee on Food Additives（FAO/WHO） safety guideline, the average daily intake dose（ADD） of Hg in the medicines was then calculated to access the risk of mercury to human health from taking CPMs.

Assessing bioaccessibility and bioavailability in vitro of phenolic compounds from freeze-dried apple pomace by LC-Q-TOF-MS

Apple pomace is one of the most abundant by-product in fruit processing industry.In this work,fresh and freeze-dried apple pomace variety‘Red Delicious’apples“I.G.P.Poma de Girona”was used to evaluate the potential amount of phenolic compounds available from the food matrix by in vitro bioaccessibility test.After the simulated digestion of freeze-dried apple pomace,an in vitro bioavailability test by using differentiated Caco-2 cells simulating the intestinal barried were assayed for 1 h,2 h,3 h and,4 h.LC-Q-TOF-MS has permitted to perform a monitoring of phloridzin,chlorogenic and gallic acids in apple pomace in apical and basal compartments.Results obtained with LC-Q-TOF-MS demonstrated that chlorogenic acid had greater percentage of bioaccesibility(44%),than phloridzin(17%)and gallic acid(7%),with similar values for fresh and freeze-dried samples.Moreover,only chlorogenic acid reported higher bioavailability in basal compartments after 3 h and 4 h,in particular about 56%of chlorogenic acid passed the transepithelial barrier.This is the first work about the evaluation of bioavailability of polyphenols from digested freeze-dried apple pomace extract.Therefore,this interesting by-product rich in polyphenol,with a great bioavailability,should be a promising ingredient to develop new functional foods.

In vitro bioaccessibility of phenolic compounds and alpha-glucosidase inhibition activity in yoghurts enriched with mango peel powder

This study investigated the potential health benefits and functional properties of mango peel powder(MPP)as a source of antioxidants and alpha-glucosidase inhibitors in yoghurts with probiotic bacteria.The study involved plain yoghurt(PY,control),yoghurt fortified with 2%mango peel powder(MY),and yoghurt fortified with 2%MPP and 1%of each probiotic culture of L.casei,L.rhamnosus,B.lactis(MPY).Bioactive potential and individual polyphenols in the products were analysed before and after in vitro gastrointestinal digestion.Results showed that both MY(0.26±0.02 mg/g GAE)and MPY(0.28±0.04 mg/g GAE)had significantly(p≤0.05)higher phenolic contents than PY(0.17±0.02 mg/g GAE).Among the 15 quantified phenolic compounds,quercetin-3-rhamnoside was highest in MPP(432.86±11.02 mg/100g dry wt.),followed by MPY(47.97±1.20)and MY(34.44±2.76 mg/100g fresh wt.).The quantities of the major individual phenolic compounds declined significantly(p<0.05)in MPP only after gastric digestion,while remained stable in MY and MPY.There were significant(p≤0.05)increments inα-glucosidase inhibition activity(6.06%and 8.47%,in MY and MPY,respectively)post intestinal digestion.The LC-ESI-QTOF-MS/MS analysis of all the sample extracts(undigested and digested)identified a total of 108 phenolic metabolites including 33 phenolic acids,42 flavonoids,11 lignans,3 alkylphenols,4 coumarins,3 tyrosols,1 stilbene,2 xanthones,4 phenolic terpene,and 3 tyrosols,2 hydroxybenzoketones,1 hydroxybenzaldehyde and 2 other phenolic metabolites.This study provides scientific evidence for the utilization of MPP fortified yoghurts as functional food products.

Effects of biochars on the bioaccessibility of phenanthrene/pyrene/zinc/lead and microbial community structure in a soil under aerobic and anaerobic conditions

The immobilization of co-contaminants of organic and inorganic pollutants by biochar is an efficient remediation strategy. However, the effect of biochar amendments on the bioaccessibility of the co-contaminants in dry versus flooded soils has rarely been compared. In batch experiments, bamboo-derived biochar（BB） had a higher sorption capacity for phenanthrene（Phe）/pyrene（Pyr）/zinc（Zn） than corn straw-derived biochar（CB）, while CB had a higher sorption capacity for lead（Pb） than BB. After 150 days of incubation, the amendments of 2% CB, 0.5% BB and 2% BB effectively suppressed the dissipation and reduced the bioaccessibility of Phe/Pyr by 15.65%/18.02%, 17.07%/18.31%and 25.43%/27.11%, respectively, in the aerobic soils. This effectiveness was more significant than that in the anaerobic soils. The accessible Zn/Pb concentrations were also significantly lower in the aerobic soils than in the anaerobic soils, regardless of treatments.The Gram-negative bacterial biomass and the Shannon–Weaver index in the aerobic soil amended with 2% CB were the highest. The soil microbial community structure was jointly affected by changes in the bioaccessibility of the co-contaminants and the soil physiochemical properties caused by biochar amendments under the two conditions. Therefore, dry land farming may be more reliable than paddy soil cultivation at reducing the bioaccessibility of Phe/Pyr/Zn/Pb and enhancing the soil microbial diversity in the short term.

Determination of the Bioaccessibility of Cadmium in Golden Thread by Physiologically Based Extraction Test Digestion Using the in vitro/Caco2 Cell Model and Subsequent Risk Assessment

Background:The ingestion of golden thread contaminated with heavy metals through the food chain leads to detrimental effects to human health.During digestion,not all of the heavy metals could be released to the gastrointestinal tract and readily to be absorbed by human body.Thus,bioaccessibility is an important issue in health risk assessments.Aims and Objectives:The aims and objectives of this study were to investigate the bioaccessibility of Cd in golden thread and assess the associated health risks based on the exposure to bioaccessible Cd.Materials and Methods:Inductively coupled plasma mass spectrometry(ICP-MS)has been applied to determine the Cd content in golden thread.Physiologically based extraction test(PBET)digestion was performed in the in vitro/Caco2 cell model to investigate the bioaccessibility of Cd in golden thread.Furthermore,the target hazard quotient(THQ)was used to assess the risks of the total and the bioaccessible content of Cd in golden thread.Results:The results revealed that the total Cd content in six batches of golden thread ranged from 3.203 to 5.723 mg/kg.After uptake by Caco2 cells,the bioaccessibility of Cd ranged from 42.36%to 59.73%.The results of the risk assessment indicated that prior to uptake by Caco2 cells,the THQ values of Cd for all batches of golden thread were greater than 1.However,after uptake by Caco2 cells,the THQ values of Cd in all samples were less than 1,thus suggesting that the risks were at a safe level.Conclusion:This study was the first to perform health risk assessment with bioaccessible heavy metals present in traditional Chinese medicine by PBET digestion using an in vitro/Caco2 cell model,thus enabling us to obtain more accurate and objective results while allowing us to avoid unnecessary government intervention and to establish more reasonable limit standards for heavy metals.