Due to the high levels of iodine present in seaweed, the ingestion of a large amount of this type of food can produce excessive intake of iodine. However, the food after ingestion undergoes different ...chemistry and physical processes that can modify the amount of iodine that reaches the systemic circulation (bioavailability). Studies on the bioavailability of iodine from food are scarce and indicate that the bioavailable amount is generally lower than ingested. Iodine in vitro bioavailability estimation from different commercialized seaweed has been studied using different in vitro approaches (solubility, dialyzability, and transport and uptake by intestinal cells). Results indicate that iodine is available after gastrointestinal digestion for absorption (bioaccessibility: 49–82%), kombu being the seaweed with the highest bioaccessibility. The incorporation of dialysis cell cultures to elucidate bioavailability modifies the estimation of the amount of iodine that may reach the systemic circulation (dialysis, 5–28%; cell culture, ≤3%). The paper discusses advantages and drawbacks of these methodologies for iodine bioavailability in seaweed.
The bioavailability of arsenic species in rice Domínguez-González, M. Raquel; Barciela-Alonso, Maria Carmen; Calvo-Millán, Valeria G. ...
Analytical and bioanalytical chemistry,
05/2020, Letnik:
412, Številka:
13
Journal Article
Recenzirano
Rice is the principal food in many countries for billions of people and one of the most consumed cereals in the world. The rice plant has the ability to bioaccumulate essential and toxic trace ...elements such as arsenic. The toxicity of the elements depends not only on their concentration but also on their chemical form and their bioavailability. The inorganic forms of arsenic are more toxic than the organic forms and the toxicity increases with decreasing oxidation states. The consumers of rice in Europe who are the most exposed to inorganic arsenic are children under three, thorough diet (rice-based food). Recently, the European Commission established the maximum levels of inorganic arsenic in foodstuffs. This regulation establishes a maximum level of inorganic arsenic of 100 μg kg
−1
in rice destined for the production of food for infants and young children. In order to know the relation between the As ingested and the arsenic absorbed, studies of bioavailability are necessary. We proposed an in vitro digestion method with dialysis to estimate this relation. Furthermore, a bioavailability study of As species in rice was performed in order to know if a change in As species occurred during the gastrointestinal digestion process. Arsenic species were determined in rice and in the dialysate fraction by high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The proposed method has been applied to different rice samples acquired in the local Spanish market.
Graphical abstract
The objective of the present study was to investigate the bioavailability of aflatoxins (AFs) from fish, and chicken and rabbit livers using an in vitro dialyzability approach. Ultrahigh-performance ...liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) was used to assess the aflatoxin content in samples, as well as in dialyzate and residue fractions after the in vitro procedure. A vortex-assisted dispersive liquid–liquid microextraction (VALLME) technique was used for preconcentrating AFs before determination. Raw samples showed bioavailability ratios of 41–45% for aflatoxin B1 (AFB1), 28–38% for aflatoxin B2 (AFB2), and 42% for aflatoxin G2 (AFG2). Aflatoxin G1 (AFG1) was not detected. The culinary process (steaming or grilling) was found to change AFs’ bioavailability (higher bioavailability ratios were found in cooked samples). AFB2 was found to be transformed into other compounds during the in vitro process, and the presence of AFB2 and AFB2 transformation/degradation products was investigated and confirmed by high-resolution mass spectrometry (HRMS).
•New insights regarding the presence of aflatoxins in fish feed suggests the need for aflatoxins control in the aquaculture sector.•Selective aflatoxins pre-concentration/clean up for reliable ...HPLC-MS/MS analysis.•Fast and low cost sample pre-treatment for aflatoxins assessment in fish feed and other feed and foodstuff.
A combined procedure based on using ultrasounds for target isolation followed by porous membrane-protected micro solid phase extraction using a molecularly imprinted polymer as an adsorbent has been developed as a highly selective extraction and clean-up procedure for isolating aflatoxins B1, B2, G1, and G2 from fish feed before ultra-high-performance liquid chromatography tandem mass spectrometry determination. Polymeric adsorbent beads have been synthesized by the precipitation polymerization method which guarantees a homogeneous particles size distribution and the integrity of the generated imprinted cavities. In addition, polymerization was performed using a higher proportion of organic solvent (toluene) in the porogen mixture, which generates MIP particles adequate for interacting with targets dissolved in organic (hydro-organic) mixtures (extracts from fish feed). These approaches led to a selective and high efficient pre-concentration method for AFs. Ultrasound-assisted extraction (10 mL of 60:40 acetonitrile/0.1 M KH2PO4 pH 6.0, 40% amplitude, continuous sonication for 7.0 min) allowed an efficient aflatoxins isolation from fish feed. In addition, the resulting pH of the extract (pH 7.0) has been found to be the optimum for performing clean-up/pre-concentration (enrichment factor of 33.3) by molecularly imprinted polymer based micro-solid phase extraction (orbital horizontal shaking speed at 150 rpm for 10 min for loading, and 5 mL of 95:5 acetonitrile/formic acid as eluting solution using ultrasounds 35 kHz for 15 min). The current proposal was shown to be an accurate and precise method through relative standard deviation of intraday and inter-day tests below 20% and analytical recoveries in the range of 80–100%. The limits of detection were within the 0.42–1.15 μg kg−1 range, quite lower than those established by European Commission guidelines for aflatoxins in animal feeds.
•Total polyphenols’ bioavailability in nuts and seeds.•In vitro dialyzability approach.•Correlation between total polyphenols’ bioavailability and copper contents.•Dializability ratios from moderate ...to high.
An in vitro dialyzability approach has been undertaken to elucidate the bioavailable fraction of the total polyphenols (TPs) of edible nuts and seeds. The TP contents in samples and in dialyzates were assessed by the Folin-Ciocalteu spectrophotometric method. Antioxidant activity was determined in selected samples, using a modified method against Trolox®. TPs and antioxidant activity in nuts/seeds were determined after applying a pressurized liquid extraction sample pre-treatment. High dialyzability ratios were assessed in most nuts/seeds (TP dialyzability percentages within the 25–91% range). The highest TP dialyzability ratios were found in raw Brazil nuts (81 ± 5%), toasted pistachios (88 ± 9%), and fried cashews (89 ± 9%), whereas TPs in pumpkin seeds were found to be very low (TPs were not detected in the dialyzable fraction). TP dialyzability was correlated with the copper content in nuts and seeds.
In this paper, the liquid extraction of benzene from aliphatic compounds (heptane, octane, cyclooctane, and methylcyclohexane) using commercial ionic liquids (ILs; 1-propyl-3-methylimidazolium ...bis{trifluoromethylsulfonyl}imide, PMimNTf2, and 1-butyl-3-methylimidazolium bis{trifluoromethylsulfonyl}imide, BMimNTf2) as solvents was studied. The liquid–liquid equilibrium (LLE) data for five ternary systems (aliphatic compound + benzene + IL) are reported at T = 298.15 K and atmospheric pressure. The cloud point method was used to determine the solubility curves, and the tie-line compositions were obtained by density measurements. From the experimental LLE data, the selectivity and the solute distribution ratio were calculated. The degree of consistency of the tie-lines was tested using the Othmer–Tobias equation, and the experimental LLE data were correlated using nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) thermodynamic models. Moreover, a systematic study about the influence of the size of the aliphatic and IL on the aromatic extraction was carried out.
The angiotensin II type 2 receptor (AT2R) exerts vasorelaxant, anti‐inflammatory, and antioxidant properties. In obesity, its activation counterbalances the adverse cardiovascular effects of ...angiotensin II mediated by the AT1R. Preliminary results indicate that it also promotes brown adipocyte differentiation in vitro. Our hypothesis is that AT2R activation could increase BAT mass and activity in obesity. Five‐week‐old male C57BL/6J mice were fed a standard or a high‐fat (HF) diet for 6 weeks. Half of the animals were treated with compound 21 (C21), a selective AT2R agonist, (1 mg/kg/day) in the drinking water. Electron transport chain (ETC), oxidative phosphorylation, and UCP1 proteins were measured in the interscapular BAT (iBAT) and thoracic perivascular adipose tissue (tPVAT) as well as inflammatory and oxidative parameters. Differentiation and oxygen consumption rate (OCR) in the presence of C21 was tested in brown preadipocytes. In vitro, C21‐differentiated brown adipocytes showed an AT2R‐dependent increase of differentiation markers (Ucp1, Cidea, Pparg) and increased basal and H+ leak‐linked OCR. In vivo, HF‐C21 mice showed increased iBAT mass compared to HF animals. Both their iBAT and tPVAT showed higher protein levels of the ETC protein complexes and UCP1, together with a reduction of inflammatory and oxidative markers. The activation of the AT2R increases BAT mass, mitochondrial activity, and reduces markers of tissue inflammation and oxidative stress in obesity. Therefore, insulin reduction and better vascular responses are achieved. Thus, the activation of the protective arm of the renin–angiotensin system arises as a promising tool in the treatment of obesity.
Angiotensin II type 2 receptor as a noval activator of brown adipose tissue in obesity.
Bioaccessibility of trace elements (Li, Be, Ti, Ga, Cu, Ag, Hg, Cd, Cs, Pt, Tl, Pb, As, Cr, Co, Ni, V, Se, Sn and Sb) and major elements (Rb, Ba, Al, Fe, Zn, Si, Ca, Mg, Mn, Mo, Sr, P and K) in tea ...infusions has been assessed using an in vitro dialyzability protocol. Gastric simulation (using pepsin solution) and intestinal simulation (using pancreatin and bile salts) were used to perform the in vitro digestion. ICP-MS, ICP-OES and FAES were used for elements determination in digested tea leaves, their infusions and the dialyzate fractions from tea infusions. Microwaves assisted acid digestion was used for the total element determination in tea leaves, while tea infusions were prepared by brewing tea leaves for 5 min in boiling water. The LODs for elements determined in tea leaves were in the range of 0.11–656 ng g−1 and 0.02–145.6 μg g−1 for trace and major elements, respectively. For elements’ determination in tea infusions, the LODs were ranged between 0.23 and 399.9 ng L−1 for trace elements and 0.2–1248 μg L−1 for major elements. The LODs for the elements in the dialyzable fraction varied from 0.018 to 142 μg L−1. The accuracy of the total element determination was evaluated using certified reference materials (Tea Leaves INCT-TL-1 and Rye Grass). The analytical recoveries were also assessed for analyzed elements in digested tea leaves (95–114%) and their infusions (92–115%), showing good recoveries. Among the studied elements, K was the most abundant element in tea leaves and tea infusions in almost all samples, followed by Ca, Mg, and P. Zn, Cs, and K showed the highest dialyzability percentages up to 84%, 76%, and 54%, respectively, followed by Si and Ca and K that show moderate to high dialyzability percentages. The accuracy of the dialysis process was evaluated using a mass-balance study.
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•Element determination in tea leaves, tea infusion and dialyzable fractions samples by ICP-MS, ICP-OES and FAES.•In vitro bioaccessibility study of trace and major elements in tea infusion using dialysis membranes.•Mass balance was used to evaluate the accuracy of the dialysis procedure.•Tea could be considered a rich dietary source of K, P, Mg, Mn, Ca, Si and Rb.
•Application of the new EFSA guidance for risk assessment of TiO2 and Ag NPs.•Biopersistence in highly dependent on matrix’s sample (standards, additive E171, or seafood).•NPs ...agglomeration/dispersion could lead misleading biopersistence rate values.•The definition of biopersistence rate should be revised for being successfully applied to foodstuff.
The European Food Safety Authority has published a guidance regarding risk assessment of nanomaterials in food and feed. Following these recommendations, an in vitro gastrointestinal digestion has been applied to study the biopersistence of TiO2 and Ag NPs in standards, molluscs and surimi. TiO2 NPs standards and TiO2 NPs/ TiO2 microparticles from E171 were not found to be degraded. Ag NPs proved to be more degradable than TiO2 NPs, but the biopersistence rates were higher than 12%, which means that Ag NPs are also biopersistent. Findings for seafood are quite similar to those obtained for TiO2 NPs and Ag NPs standards, although the calculation of the biopersistence rate proposed by the EFSA was not found to be straightforward for foodstuff (the use of the NPs concentration in the sample instead of the NPs concentration at initial time (sample mixed with the gastric solution before enzymatic hydrolysis) has been proposed.
