Bioaccessibility of essential elements from white cheese, bread, fruit and vegetables

Influence of Cooking Technique on Bioaccessibility of Bioactive Compounds in Vegetable Lentil Soup

Vegetables and legume soups contain various essential and bioactive constituents such as vitamin C, carotenoids, and phenolics. Antioxidant activity characteristics related to those compounds are well known to contribute profusely to human health. The cooking technique affects the bioavailability of nutrients and bioactive compounds, making it crucial to explore optimal alternatives to maximize them. The objective of this study was to explore the influence of different cooking techniques (boiling, pressure cooking, sous-vide, and cook-vide) on the physicochemical properties and bioactive characteristics of a ready-to-eat vegetable lentil soup. For this, the bioaccessibility of those compounds was assessed through an in vitro simulated gastrointestinal methodology. The firmness of vegetables was established to define treatments' cooking times, allowing subsequent comparison of the nutritional and functional properties of the soups. The color of vegetables was also evaluated as a quality parameter, which contributed to providing a global vision of the process impact. The results revealed that in vitro digestion (IVD) caused a decrease in all bioactive compound determinations for all cooking treatments of up to 72% for total phenols, 92% for lycopene, 98% for carotenoids, and 100% for vitamin C. Additionally, the antioxidant activity of the soups after thermal treatment improved up to 46% measured by the DPPH method. This study emphasizes the importance of considering the digestion process in the selection of the most adequate cooking technique. After IVD, traditional cooking (boiling) reached the maximum total carotenoid and lycopene contents; cook-vide and pressure-cooking techniques provided the highest total phenol content, showing these three techniques to have the maximum antioxidant capacity.

In Vitro Assessment of the Bioaccessibility of Zn, Ca, Mg, and Se from Various Types of Nuts

The bioaccessibility of zinc (Zn), calcium (Ca), magnesium (Mg), and selenium (Se) from various nuts (Brazil nuts, walnuts, peanuts, almonds, cashews, pecans, hazelnuts, macadamia nuts, and pistachios) was assessed using a simulated two-phase model of enzymatic digestion in vitro. The levels of Zn, Mg, and Ca were determined by atomic absorption spectrometry, and Se was measured by inductively coupled plasma-mass spectrometry. All tested nuts were good sources of Mg, and most, except macadamia nuts, were also good sources of Zn (the standard portion covers over 15% of NRV-R (UE) 1924/2006). Brazil nuts had the highest Se content. Almonds and Brazil nuts were rich in Ca. Se demonstrated the highest bioaccessibility from nuts (27.7% to 70.65%), whereas Ca exhibited the lowest bioaccessibility (below 9%). Pistachios had the highest Zn bioavailability, while cashews excelled in Mg bioaccessibility. Macadamia and pistachios were top for Ca bioaccessibility, and Brazil nuts for Se. Bioaccessibility is positively correlated with fat (for Zn: r = 0.23), carbohydrates (for Mg: 0.44; for Ca: 0.35), and sugar content (for Zn: r = 0.36; for Mg: 0.46; for Ca: 0.40).

Total Zn of foods and bioaccesible fractions in the small and large intestine after in vitro digestion and fermentation with fecal material of healthy adults and children: Influence of culinary techniques

The healthy status of human beings is associated with an appropriate nutritional status in Zn, which must firstly be bioavailable. We measured the total Zn amount and its bioaccesibility in raw foods and after cooking by common culinary techniques. These foods were submitted to an in vitro digestion and fermentation with faecal inocula from healthy adults and children to evaluate Zn bioaccesibility in the small and large intestine. Mean total Zn amount provided by foods was 8.080 μg/g. Zn amount released from food in the small intestine was significantly different among several food groups and lower in raw vegetal foods compared to cooked ones (frying, roasting and grilling; p < 0.05); the same behaviour was found in the large intestine for healthy children. Zn bioaccesibility in the large intestine varied statistically according to the subjects' idiosyncrasies, and was higher in healthy children (p < 0.05) probably due to growth demands and different composition of the colonic microbiota. In healthy adults and children, the bioaccesible fractions were 33.0 ± 20.4 % for the small intestine, 16.4 ± 22.0 and 59.6 ± 29.9% for the large one, and the non-bioaccessible ones 50.6 ± 19.9 and 7.4 ± 9.1%, respectively.

Edible Halophytes with Functional Properties: In Vitro Protein Digestibility and Bioaccessibility and Intestinal Absorption of Minerals and Trace Elements from Australian Indigenous Halophytes

Halophytes are considered emerging functional foods as they are high in protein, minerals, and trace elements, although studies investigating halophyte digestibility, bioaccessibility, and intestinal absorption are limited. Therefore, this study investigated the in vitro protein digestibility, bioaccessibility and intestinal absorption of minerals and trace elements in saltbush and samphire, two important Australian indigenous halophytes. The total amino acid contents of samphire and saltbush were 42.5 and 87.3 mg/g DW, and even though saltbush had a higher total protein content overall, the in vitro digestibility of samphire protein was higher than the saltbush protein. The in vitro bioaccessibility of Mg, Fe, and Zn was higher in freeze-dried halophyte powder compared to the halophyte test food, suggesting that the food matrix has a significant impact on mineral and trace element bioaccessibility. However, the samphire test food digesta had the highest intestinal Fe absorption rate, whereas the saltbush digesta exhibited the lowest (37.7 vs. 8.9 ng/mL ferritin). The present study provides crucial data about the digestive "fate" of halophyte protein, minerals, and trace elements and increases the understanding of these underutilized indigenous edible plants as future functional foods.

Bioaccessibility of glucosinolates, isothiocyanates and inorganic micronutrients in cruciferous vegetables through INFOGEST static in vitro digestion model

Green tissues and seeds from cruciferous vegetables growing in conventional and ecological conditions (Brassica carinata; Brassica rapa; Eruca vesicaria and Sinapis alba) were analyzed to determine their contents of glucosinolates, isotihiocyanates (ITCs) and inorganic micronutrients (Ca, Cr, Cu, Fe, Mn, Ni, Se and Zn), and the bioaccessibility of these compounds. Regarding total contents and bioaccessibility values of these compounds, no clear difference was found between the organic and conventional systems. Glucosinolates bioaccessibility present in green tissues were high, with values around 60-78%. In additon, it was quantified in bioaccessible fraction ITCs concentrations such as Allyl - ITC; 3 - Buten - 1 - yl - ITC and 4 - Penten - 1 - yl - ITC. Trace elements bioaccessibility in green tissues was also high for Ca (2.26-7.66 mg/g), Cu (0.60-2.78 µg/g), Se (9.93-74.71 µg/Kg) and Zn (12.98-20.15 µg/g). By contrast, the bioaccessibility of glucosinolates and trace elements in cruciferous seeds was extremely low. With the exception of Cu, these bioaccessibility percentages did not exceed 1% in most cases.

Bioaccessibility of Cu, Mn, Fe, and Zn in Fruit and Vegetables by the In Vitro UBM and Statistical Evaluation of the Results

The total, gastric, and gastro-intestinal Cu, Mn, Fe, and Zn concentrations in eight fruit and vegetable samples were investigated. The unified bioaccessibility method (UBM) developed by BARGE (Bioaccessibility Research Group of Europe) was performed for in vitro bioaccessibility experiments. Total and bioaccessible concentrations of Cu, Mn, Fe, and Zn were determined by ICP-OES and ICP-MS, respectively. The accuracy of the methods was verified using BGS 102 for the BARGE UBM and SRM 1573a for total analysis. The mean BF (%) order for Cu, Mn, Fe, and Zn was Mn (101) > Zn (88) > Fe (60) > Cu (30) in gastric phase and Mn (78) > Zn (69) > Fe (46) > Cu (29) in gastro-intestinal phase. The results show that Mn and Zn in all the samples have the greatest bioaccessible values, while the values for Cu are much lower. The relationships among total, gastric, and gastro-intestinal element concentrations were investigated using statistical analysis such as correlation analysis, principal component analysis (PCA), and cluster analysis (CA). Total and bioaccessible Cu, Mn, and Zn concentrations were significantly correlated with each other.

Nutritional composition and minerals bioaccessibility of commercial fruit flours

Commercial fruit flours were evaluated concerning: (i) the nutritional composition (proximate composition, total phenolic content, and minerals content), (ii) their contribution to estimated mineral daily intake, (iii) the bioaccessibility of essential minerals using the in vitro INFOGEST digestion method and (iv) the influence of their chemical composition on minerals bioaccessibility. The 20 samples analysed presented high variability concerning the content of dietary fibre (7.5 to 69.7 g/100 g), carbohydrates (4.1 to 74.9 g/100 g), protein (2.9 to 12.9 g/100 g), ash (1.0 to 7.0 g/100 g), lipids (1.0 to 8.1 g/100 g) and total phenolic content (2.9 to 41.0 mg GAE/g. The mineral content of fruit flours provides a great contribution to the daily mineral requirements (especially Mg, Fe, Mn and Cu) with a daily intake of 30 g and very low contribution to the daily requirements of Na (0–3%). Low bioaccessibility was observed for Ca (18.0%) and Fe (28.9%), while Mg was the most bioaccessible mineral (81.5%). Though, the bioaccessible fraction of Mg showed negative correlation with total dietary fibre content (r = − 0.77) and lipids (r = − 0.46).

Mineral and Trace Elements in Nutritious Flours: Total Contents, In Vitro Bioaccessibility and Contribution to Dietary Intake

The consumption of fruits, vegetables, and cereals in the form of flour has been an alternative for the intake of nutrients, currently seen in a society that seeks a healthier diet. Thus, the assessment of total contents and bioaccessibility is important to better understand the actual intake of nutrients or contaminants present in foods. The objective of this study was to determine the total content and estimate the bioaccessible fraction of Cu, Fe, and Zn in nutritious flours by inductively coupled plasma optical emission spectrometry (ICP OES) after microwave acid digestion. Bioaccessibility was assessed using the in vitro method, taking into account the entire gastrointestinal tract (Unified Bioaccessibility Method (UBM)). The following concentration ranges, in μg g^-1, were found: Ca (341-6275), K (2984-13,953), P (476-6110), Na (< 0.39-2995), Fe (1.4-167), Cu (< 0.01-59.6), and Zn (< 0.07-30.3). Principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed a tendency towards the formation of three groups. The bioaccessible fractions for Cu, Fe, and Zn were considered low, ranging from 0.96 to 40% in the gastrointestinal phase and from 4.1 to 100% in the gastric phase.

In Vitro Digestibility of Minerals and B Group Vitamins from Different Brewers' Spent Grains

Brewers' spent grain (BSG), the main by-product of the brewing industry, is a rich source of minerals and water-soluble vitamins such as thiamine, pyridoxine, niacin, and cobalamin. Bioaccessibility through in vitro digestion is an important step toward the complete absorption of minerals and B group vitamins in the gastrointestinal system. Inductively coupled plasma optical emission spectrometry (ICP-OES) together with inductively coupled plasma quadrupole mass spectrometry (ICP-MS) was used for the quantification of the macro- and micro-minerals. An ultra-high performance liquid chromatography (UHPLC) system coupled with a diode array detector (DAD) was used for B group vitamin identification. Four different industrial BSG samples were used in the present study, with different percentages of malted cereals such as barley, wheat, and degermed corn. Calcium's bioaccessibility was higher in the BSG4 sample composed of 50% malted barley and 50% malted wheat (16.03%), while iron presented the highest bioaccessibility value in the BSG2 sample (30.03%) composed of 65% Pale Ale malt and 35% Vienna malt. On the other hand, vitamin B1 had the highest bioaccessibility value (72.45%) in the BSG3 sample, whilst B6 registered the lowest bioaccessibility value (16.47%) in the BSG2 sample. Therefore, measuring the bioaccessibilty of bioactive BSG compounds before their further use is crucial in assessing their bioavailability.

Bioaccessibility of Macrominerals and Trace Elements from Tomato (Solanum lycopersicum L.) Farmers’ Varieties

Traditional farmers’ varieties of tomato grown under extensive farming techniques are considered delicious and healthy foods and are preferred by local consumers. Tomatoes are an important component of a healthy diet, as they provide essential micronutrients, including minerals, which are vital to healthy development, disease prevention, and wellbeing. Given the considerable dietary intake of tomatoes and the scarcity of information about the bioaccessibility of inorganic constituents in this fruit, this study was carried out to evaluate the content and bioaccessibility of minerals (macro- and microelements) in tomato farmers’ varieties widely cultivated in northeastern Portugal homegardens. Among the macroelements, K stood out as the most abundant mineral in the studied varieties, followed by Mg, Ca, and Na. Regarding the microelements, while the yellow tomato had higher concentrations of Fe and Cu, the round tomato had more Zn and Mn. The in vitro bioaccessibility assessment showed that, among the macroelements, Mg was more bioaccessible than Ca and K when all the tomato varieties were considered together. Among the microelements, Cu seemed to be the most bioaccessible. Although the contribution of a 100 g serving of the studied tomato farmers’ varieties to the dietary reference intakes (DRIs) of minerals is relatively low, this food could contribute to reaching these mineral requirements, as it is included in the diet of most of the population, especially in Mediterranean regions.

In Vitro Bioaccessibility of Bioactive Compounds from Rosehip-Enriched Corn Extrudates

The rosehip (Rosa canina L.) fruit has gained researchers′ attention due to its rich chemical composition in vitamin C, phenols, carotenoids, and high antioxidant activity; meanwhile, polymers such as pea protein are generally recognized as exhibiting a protection role against the extrusion process. Corn snacks extrudates obtained by replacing corn flour with 10% R. canina powder (R) and 10% R. canina with pea protein (RPP) were evaluated for the physicochemical, textural, optical, and nutritional characteristics. A sample manufactured without R. canina powder was used as a control. Hardness, crispiness, chewiness, and solubility index (WSI) of the final extrudates were improved by addition of R. canina and pea protein powder (PP); meanwhile, b* (yellow/blue coordinate), C (chroma), and h* (tone) optical parameters were significantly different from the control sample (p < 0.05). Extrusion highlighted a negative impact on total phenols, carotenoids, vitamin C, and antioxidant activity extrudates, while PP exhibited a good protection against the extrusion process. In vitro digestion increased the bioaccessibility of vitamin C, folate, antioxidant activity, total phenols, and total carotenoids mainly on RPP extrudates.

Mineral Composition and Bioaccessibility in Rocket and Purslane after Zn Biofortification Process

Zinc (Zn) is an essential key nutrient in different biochemical and physiological processes. The nutritional deficit of this mineral element is estimated to affect the health of over 3 billion people worldwide. Several strategies are available to reduce the negative impact of mineral malnutrition; among them, biofortification is the practice of deliberately increasing the nutrients and healthy compounds in the edible parts of vegetables. This study aims to evaluate Zn bioaccessibility in biofortified and non-biofortified rocket and purslane using an in vitro gastrointestinal digestion process and measure the concentration of other mineral elements (Al, B, Ca, Fe, K, Mg, Mn, and Sr) released during the digestion process from rocket and purslane biofortified with Zn. The bioaccessible Zn in biofortified rocket and purslane ranged from 7.43 to 16.91 mg/kg, respectively. In addition, the daily intake, the RDA coverage (%), and the hazard quotient (HQ) for the intake of Zn (resulting from the consumption of 100 g of rocket and purslane) were calculated. The calculated HQ highlights the safety of these baby leaf vegetables. The study confirms that it is possible to obtain Zn-biofortified rocket and purslane with high Zn bioaccessibility by adopting an appropriate mineral plant nutrition solution enriched in Zn.

Effect of processing on the bioaccessibility of essential minerals in goat and cow milk and dairy products assessed by different static in vitro digestion models

The study evaluated the effect of goat and cow milk processing on the bioaccessibility of calcium, magnesium and zinc using different methods following the static in vitro simulation of gastrointestinal digestion: solubility and dialysis models. Raw goat and cow milks were processed to obtain pasteurized milk, yogurt and cheese. In general, goat milk and dairy products presented higher bioaccessibility of Ca and Mg than cow milk and dairy products. The milk processing affected the minerals bioaccessibility indicating the importance of food structure, composition and minerals equilibrium on the in vitro digestion and bioaccessibility prediction. The potential absorptions of Ca and Zn were higher in cheeses when compared to the milks and yogurts, independently of the method used. The minerals bioaccessibility evaluated by the solubility method was higher than the obtained by dialysis method for all the products evaluated.

Effect of Adding Resistant Maltodextrin to Pasteurized Orange Juice on Bioactive Compounds and Their Bioaccessibility

Resistant maltodextrin (RMD) is a water-soluble and fermentable functional fiber. RMD is a satiating prebiotic, reducer of glucose and triglycerides in the blood, and promoter of good gut health, and its addition to food is increasingly frequent. Therefore, it is necessary to study its potential effects on intrinsic bioactive compounds of food and their bioaccessibility. The aim of this study was to evaluate the effect of adding RMD on the bioactive compounds of pasteurized orange juice with and without pulp, and the bioaccessibility of such compounds. RMD was added at different concentrations: 0 (control sample), 2.5%, 5%, and 7.5%. Ascorbic acid (AA) and vitamin C were analyzed using HPLC, whereas total phenols, total carotenoids (TC), and antioxidant capacity were measured using spectrophotometry. After that, sample in vitro digestibility was assessed using the standardized static in vitro digestion method. The control orange juice with pulp presented significantly higher values of bioactive compounds and antioxidant capacity than the control orange juice without pulp (p < 0.05). RMD addition before the juice pasteurization process significantly protected all bioactive compounds, namely total phenols, TC, AA, and vitamin C, as well as the antioxidant capacity (AC) (p < 0.05). Moreover, this bioactive compound protective effect was higher when higher RMD concentrations were added. However, RMD addition improved phenols and vitamin C bioaccessibility but decreased TC and AA bioaccessibility. Therefore, the AC value of samples after gastrointestinal digestion was slightly decreased by RMD addition. Moreover, orange pulp presence decreased total phenols and TC bioaccessibility but increased AA and vitamin C bioaccessibility.

Probiotic Potential, Iron and Zinc Bioaccessibility, and Sensory Quality of Uapaca kirkiana Fruit Jam Fermented with Lactobacillus rhamnosus Yoba

Uapaca kirkiana is an underutilised indigenous fruit tree (IFT) found in the miombo ecological zone in sub-Saharan Africa. Furthermore, sub-Saharan Africa is home to many nutritionally insecure people who suffer from micronutrient deficiency. The incorporation of probiotic strains in jams as a possible way of enhancing mineral accessibility, food quality, and health is limited in Africa. This study monitored the probiotic potential, bioaccessible iron and zinc, and organoleptic properties of U. kirkiana fruit jam fermented with L. rhamnosus yoba. U. kirkiana fruits were collected from semiarid rural areas of Zimbabwe. The L. rhamnosus yoba strain was obtained from the Yoba for Life Foundation, Netherlands. Mineral and biochemical properties of the probiotic jam were analysed using AOAC standard methods. The U. kirkiana fruit tree was ranked first as a food resource by most rural populations in Zimbabwe. The probiotic jam formulation had 55% (wt/vol) U. kirkiana fruit pulp, 43% (wt/vol) sugar, 1.25% (wt/vol) pectin, 0.5% (wt/vol) citric acid, and 0.25% (wt/vol) L. rhamnosus yoba strain. The probiotic jam had 6.2 ± 0.2 log CFU/mL viable L. rhamnosus yoba cells. Iron and zinc content (mg/100 g w.b.) was 4.13 ± 0.22 and 0.68 ± 0.02 with pH 3.45 ± 0.11, respectively. Nutrient content was g/100 g w.b., carbohydrate 66 ± 4.1, fat 0.1 ± 0.01, crude protein 0.2 ± 0.01, ash 0.7 ± 0.02, and crude fiber 0.3 ± 0.01. Bioaccessible iron and zinc were 6.55 ± 0.36% and 16.1 ± 0.50% and increased by 4% and 2% in the probiotic jam, respectively. Mineral bioaccessibility and nutrient content were significantly different (p < 0.05) in jam with 0.25% L. rhamnosus yoba. Jam acceptance rating was 83%. The probiotic jam can be used as a sustainable food containing probiotic with potential nutritional and health benefits.

Manganese in the Diet: Bioaccessibility, Adequate Intake, and Neurotoxicological Effects

Manganese (Mn) is an essential element that participates in several biological processes. Mn serves as a cofactor for several enzymes, such as glutamine synthetase and oxidoreductases, that have an important role in the defense of the organisms against oxidative stress. The diet is the main source of Mn intake for humans, and adequate daily intake levels for this metal change with age. Moreover, in higher amounts, Mn may be toxic, mainly to the brain. Here, we provide an overview of Mn occurrence in food, addressing its bioaccessibility and discussing the dietary standard and recommended intake of Mn consumption. In addition, we review some mechanisms underlying Mn-induced neurotoxicity.

Stability of Arsenic Species During Bioaccessibility Assessment Using the In Vitro UBM and HPLC-ICP-MS Detection

The stability of four major arsenic (As) species during application of the BARGE (Bioaccessibility Research Group of Europe) unified bioaccessibility method (UBM) has been assessed. The concentrations of As species in the UBM gastric and gastro-intestinal (gastric + intestinal) phases were determined using HPLC-ICP-MS whilst the total As content in the samples was determined using ICP-MS alone. The arsenic species studied were arsenite As(III), arsenate As(V), dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA). These species were separated in 10 min using an anion exchange column (Hamilton PRP-X100) with a mobile phase containing 20 mmol L^-1 NH₄H₂PO₄/1% methanol (pH 6.0). The recoveries of arsenic species spiked into the gastric and gastro-intestinal fluids were in the range 90-108%. No interconversion between As species was observed as a result of applying the BARGE UBM, which is a particularly important finding for the reliability of As(III) measurements. The accuracy of the BARGE UBM for in vitro extractable As(V) was verified using British Geological Survey (BGS) guidance material 102 (an ironstone soil). For a commercial rice sample, the bioaccessibility sequence of As was DMA > As(III) > As(V) for the gastric phase and As(III) > DMA > As(V) for the gastro-intestinal phase.

In vitro oral bioaccessibility investigation and human health risk assessment of heavy metals in wheat grains grown near the mines in North China

There is limited research on the effects of gut microbiota on bioaccessibility of heavy metals in wheat grains. In this study, bioaccessibility of heavy metals (Cu, Cd, Pb, and Zn) in wheat was determined to elucidate transfer characteristics in the soil-grain-human systems near two large-scale mining areas in Shandong Province, North China using the physiologically-based extraction test (PBET) in combination with a simulator of human intestinal microbial ecosystems (SHIME). The results showed the bioconcentration factors (BCFs) of Cu, Cd, Pb, and Zn were 0.123-0.327, 0.188-0.478, 0.019-0.099, and 0.262-0.825, respectively. Significant and positive correlations were observed between heavy metals in soils and wheat grains. In the simulated colon phase, bioaccessibility of Cd and Zn significantly decreased to 7.81% and 8.81%, respectively, being 53% and 64% of that in the simulated small intestinal phase. However, bioaccessibility of Pb showed an obvious escalating trend, being 2.4 times higher than that of intestinal incubation. Based on the estimated daily intakes and contribution, the relative high contribution of Cu to the benchmark dose in both phases, Cu metabolism by human gut microbiota should be considered in human health risk assessment regarding wheat consumption.

Simplified Method of Multi-Elemental Analysis of Dialyzable Fraction of Tea Infusions by FAAS and ICP OES

A fast and straightforward sample preparation procedure of the dialyzable fraction of infusions of teas prior to their analysis on Al, Ba, Ca, Cu, Fe, Mg, Mn, Ni, Sr, and Zn contents by flame atomic absorption spectrometry (FAAS) and inductively coupled plasma optical emission spectrometry (ICP OES) was developed and validated. The proposed methodology was based on acidification with HNO3 only and demonstrated good analytical performance, i.e., precision (0.80-5.0%), accuracy (< 5%), recoveries of elements (97.4-105%), and their detection limits (0.075-1.1 μg L-1) along with linearity of calibration curves in the whole studied concentration ranges. Applicability of the evaluated procedure, being a useful alternative to time-consuming wet digestions, was tested by determining bioaccessibility of elements in 20 infusions of black (BT) and green (GT) teas as assessed with the aid of in vitro gastrointestinal digestion. Average contributions of bioaccessible fractions (%) of studied metals were as follows: 1.18 (Al)-40.7% (Ca) and 4.65% (Al)-46.3% (Ca) for BTs and GTs, respectively. Drinking daily four cups (1 L) of tea, recommended dietary intakes (RDIs) of Ca, Cu, Fe, Mg, and Zn were covered to a small degree (< 1.5%). Only bioaccessibility of Mn highly contributed to RDI for this metal. According to provisional tolerable weekly intakes (PTWIs) for toxic elements such as Al and Ni, consumption of both types of teas should not represent any health risk. Additionally, analysis of variance of results clearly indicated that BTs and GTs were mostly differentiated due to concentrations of the bioaccessible fraction of Al, Ba, Cu, and Ni.

Aluminum content and effect of in vitro digestion on bioaccessible fraction in cereal-based baby foods

The aim of this work was to determine the total concentration and the effect of in vitro digestion on the bioaccessible fraction of aluminum (Al) in 35 different cereal-based baby food samples and estimate the exposure to this element considering the consumption of this product. Total Al content was determined by inductively coupled plasma optical emission spectrometry after oxidative microwave digestion. An in vitro digestion method was applied and optimized to evaluate the bioaccessible fraction. The methods performance was efficient for both approached analysis and presented limits of detection and quantitation of 53 μg kg^-1 and 89 μg kg^-1, respectively. Total concentration and bioaccessibility varied according to the product composition (rice, oat, wheat, barley, corn, multicereal and fruit). Multicereals and fruit-based (plum) cereals presented the highest total Al concentrations (8.82 mg kg^-1 and 7.49 mg kg^-1, respectively), whilst lower values were observed for corn and rice flour cereals (0.92 mg kg^-1 and 1.09 mg kg^-1, respectively). The bioaccessible fraction varied from 1.5% to 10.4% in the evaluated samples. Exposure to Al was estimated and compared with the Provisional Tolerable Weekly Intake (PTWI) of 2 mg kg^-1 body weight. The results showed that the daily consumption of three portions of cereals contributes up to 10.48% of the PTWI, when considering the total Al concentration reported in this study.

A Guide to Human Zinc Absorption: General Overview and Recent Advances of In Vitro Intestinal Models

Zinc absorption in the small intestine is one of the main mechanisms regulating the systemic homeostasis of this essential trace element. This review summarizes the key aspects of human zinc homeostasis and distribution. In particular, current knowledge on human intestinal zinc absorption and the influence of diet-derived factors on bioaccessibility and bioavailability as well as intrinsic luminal and basolateral factors with an impact on zinc uptake are discussed. Their investigation is increasingly performed using in vitro cellular intestinal models, which are continually being refined and keep gaining importance for studying zinc uptake and transport via the human intestinal epithelium. The vast majority of these models is based on the human intestinal cell line Caco-2 in combination with other relevant components of the intestinal epithelium, such as mucin-secreting goblet cells and in vitro digestion models, and applying improved compositions of apical and basolateral media to mimic the in vivo situation as closely as possible. Particular emphasis is placed on summarizing previous applications as well as key results of these models, comparing their results to data obtained in humans, and discussing their advantages and limitations.

In vitro bioaccessibility of minerals from microalgae-enriched cookies

Microalgae can be used as an ingredient to enrich cookies with minerals. Cookies enriched with microalgae presented a higher content in minerals compared to control samples.

Bioavailability Assessment of Copper, Iron, Manganese, Molybdenum, Selenium, and Zinc from Selenium-Enriched Lettuce

Cu, Fe, Mn, Mo, Selenium (Se), and Zn bioavailability from selenate- and selenite-enriched lettuce plants was studied by in vitro gastrointestinal digestion followed by an assay with Caco-2 cells. The plants were cultivated in the absence and presence of two concentrations (25 and 40 µmol/L of Se). After 28 days of cultivation, the plants were harvested, dried, and evaluated regarding the total concentration, bioaccessibility, and bioavailability of the analytes. The results showed that biofortification with selenate leads to higher Se absorption by the plant than biofortification with selenite. For the other nutrients, Mo showed high accumulation in the plants of selenate assays, and the presence of any Se species led to a reduction of the plant uptake of Cu and Fe. The accumulation of Zn and Mn was not strongly influenced by the presence of any Se species. The bioaccessibility values were approximately 71%, 10%, 52%, 84%, 71%, and 86% for Cu, Fe, Mn, Mo, Se, and Zn, respectively, and the contribution of the biofortified lettuce to the ingestion of these minerals is very small (except for Se and Mo). Due to the low concentrations of elements from digested plants, it was not possible to estimate the bioavailability for some elements, and for Mo and Zn, the values are below 6.9% and 3.4% of the total concentration, respectively. For Se, the bioavailability was greater for selenite-enriched than selenate-enriched plants (22% and 6.0%, respectively), because selenite is biotransformed by the plant to organic forms that are better assimilated by the cells.

In vitro gastrointestinal digestion to evaluate the total, bioaccessible and bioavailable concentrations of iron and manganese in açaí (Euterpe oleracea Mart.) pulps

Açaí pulp consumption has increased in Brazil and worldwide. Recently, a high average content of manganese (450 mg/kg) was observed in açaí pulp, raising the hypothesis of toxicological effects associated to its ingestion. However, the total concentration of an element does not reflect the real benefits and risks of consuming a food. In this context, the total, bioaccessible and bioavailable concentrations of Fe and Mn were assessed in 9 açaí pulps. Fe and Mn contents ranged from 27.6 to 73 and from 145 to 1197 mg kg^-1, respectively. Fe and Mn bioaccessibilities represented from 29 to 40 and from 39 to 55% of total amounts. Fe bioavailabilities were lower than LOQ and those of Mn varied from 8 to 17% of total. A daily consumption of 100 g of açaí pulp exceeds by at least 1.5-fold the recommended Mn daily intakes for adults whereas poorly contributes to Fe intakes. Since the lowest Mn bioaccessible and bioavailable fraction corresponded to a Mn intake value higher than the tolerable upper intakes for children and that high amounts of Mn intake may impair Fe absorption, higher açaí consumption may be worrisome. Future nutritional, toxicological and speciation studies must be undertaken.

Bioaccessibility of Some Essential Minerals in Three Selected Australian Pulse Varieties Using an In Vitro Gastrointestinal Digestion Model

Australian produced pulse grains are exported worldwide, predominantly to developing countries where severe essential mineral deficiencies putatively subsist. An in vitro digestion model that simulates human gastric, intestinal and colonic digestion and fermentation, was used to examine the bioaccessibility of Fe, Mg, K, Ca, P, Zn, Mn, and Cu in commercially available cultivars of Australian field pea, lentil, and sweet lupin. The hull and dehulled seeds were prepared following a traditional cooking method, and quantities of bioaccessible minerals were assessed at each stage of in vitro digestion using ICP-OES elemental analyses. Results revealed that dehulled field pea (100 g dry weight) had the highest bioaccessible quantity of Fe (2.44 ± 0.73 mg), K (717.10 ± 56.66 mg), P (272.88 ± 9.30 mg), Zn (1.72.028 ± 0.28 mg), and Cu (0.41 ± 0.02 mg). Dehulled lupin was the best source of Mg (138.62 ± 1.53 mg) and Mn (1.28 ± 0.0.06 mg), and lentil hull showed the greatest Ca bioaccessible quantity (116.33 ± 16.73 mg/100 g dry weight). Additionally, the fed state digestion (11.7 mg bile/mL sample) increased the bioaccessibility of all elements significantly (P < 0.05) compared to fasted (1.95 mg bile/mL sample), except for Zn and Mn in lupin and lentils. These results demonstrated that dehulled seeds possess higher mineral bioaccessibility on a percentage basis compared with hulls, and that the fed state of in vitro digestion generally improved the mineral solubility significantly (P < 0.05). PRACTICAL APPLICATION: This research aimed to assess the prospective biological accessibility of various essential elements in three commercially available Australian pulses. Results of the study provided an insight into the contents of essential minerals in Australian pulses and illustrated the impact of traditional cooking of dehulled pulses on these minerals bioaccessibility. These findings will provide the consumers with information about some nutritional aspects of major Australian pulses.

Effect of inoculation with arbuscular mycorrhizal fungi and blanching on the bioaccessibility of heavy metals in water spinach (Ipomoea aquatica Forsk.)

A plant's tolerance to heavy metals (HMs) and its detoxification mechanisms are associated with the subcellular distribution of HMs and their chemical forms. In this study, water spinach (Ipomoea aquatica Forsk.) was grown in two soils contaminated with a single HM (cadmium, Cd) or combined HMs (Cd and nickel, Ni). Inoculation of arbuscular mycorrizal fungi (AMF) was conducted to increase the accumulation of phosphorus (P) in plants. One major exception was to decrease the migration and accumulation of HMs in edible parts by the formation of P-HM complexes. The effects of blanching and simulated digestion on bioaccessibility were also assessed. The experimental results showed that the water spinach species used in this study had a high capacity to accumulate HMs. AMF treatment improved water spinach growth and decreased the accumulation of Ni but not that of Cd. Soluble and inorganic Cd and Ni were the major subcellular fractions and chemical forms in water spinach; these two HMs also exhibited higher migration capacities in comparison to chromium (Cr). Relative to raw tissues, 45-84% of Cd, Cr, and Ni were leached after blanching. Approximately 32-55%, 16-50%, and 27-40% of Cd, Cr, and Ni, respectively, were bioaccessible and could be metabolized by in vitro digestive fluids.

The Distribution of Essential, Trace, and Nonessential Minerals in Weanling Male Rats Fed Sheep or Cow Milk

SCOPE

The aim of the study is to determine the effects of sheep milk consumption in comparison to cow milk on the mineral distribution in the soft organs and serum in a growing animal model system. As the mineral composition of cow and sheep milk differs, different effects on the bio-accumulations in the body may be observed. Differences in the mineral composition of cow and sheep milk may lead to different bioavailability or accumulation of minerals in the body. Newly weaned rats were fed either cow milk, sheep milk, or sheep milk diluted so that it had the same solid content as cow milk. At the end of the feeding trial, the concentration of minerals in the organs and plasma of the rats was assessed. The results indicate that the consumption of the high level of minerals in sheep milk does not have any negative effects in the rat model.

METHODS AND RESULTS

Newly weaned male rats were fed ad libitum for 28 days on either cow milk, sheep milk, or sheep milk diluted to have the same concentration of milk solids as cow milk. Animals were euthanized and the soft organs and serum were harvested and then analyzed for mineral composition by inductively coupled plasma MS. Rats fed sheep milk had lower iron concentrations in the liver and higher concentrations of rubidium and cesium in all of the soft organs. The growth rate of the rats was not affected by the type of milk consumed.

CONCLUSION

The concentration of essential and trace minerals in the liver is found to be significantly different between rats fed sheep milk compared to those fed cow milk (p < 0.05). The consumption of sheep milk does not affect the growth of animals.

Estimation of the bioaccessibility and bioavailability of Fe, Mn, Cu, and Zn in Chinese vegetables using the in vitro digestion/Caco-2 cell model: the influence of gut microbiota

The influence of the human gut microbiota on the bioaccessibility and bioavailability of trace elements in vegetables has barely been studied. An in vitro digestion model combining the physiologically based extraction test (PBET) and the Simulator of Human Intestinal Microbial Ecosystem (SHIME) was applied. Results showed that the gut microbiota increased the bioaccessibility of iron (Fe) in ten test vegetables by 1.3-1.8 times, but reduced the bioaccessibility of manganese (Mn), copper (Cu), and zinc (Zn) in vegetables in the colon phase by 3.7% to 89.6%, 24.8% to 100.0%, and 59.9% to 100.0%, respectively. Using the Caco-2 cell model to simulate the human absorption process, the bioavailable contents and the bioavailability of the trace elements were further determined. Swamp cabbage was the best source of Fe and Cu; spinach and lettuce provided the highest amounts of bioavailable Mn and Zn, respectively. Referring to the daily reference intakes of trace elements, the obtained data provide a scientific basis for both reasonable ingestion of vegetables in diets and diversification of diets.