Trace metals in marine foodstuff: Bioavailability estimation and effect of major food constituents

Tracing metals in Mediterranean and Atlantic Sardina pilchardus: Unveiling impacts on food safety

This study evaluates the concentration of metals and trace elements (Al, Cd, Cu, Fe, Li, Pb, Zn) in the muscle tissue of Sardina pilchardus from three northeast Atlantic localities (Lisbon, Canary Islands, Rabat) and two western Mediterranean sites (Málaga, Cartagena) to assess food safety and environmental impact. A total of 100 sardines were sampled between January and June 2019, with specimens collected, homogenized by size and weight, and analyzed for metal content using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Results show significant geographical variation in metal concentrations, with Cartagena exhibiting the highest levels due to industrial and urban activities, while the Canary Islands had the lowest, likely influenced by geographical isolation and stringent environmental regulations. Intermediate levels were observed in Lisbon, Rabat, and Málaga, with Rabat ranking second highest. Importantly, none of the samples exceeded EU safety limits for lead (0.3 mg/kg) or cadmium (0.25 mg/kg), confirming their suitability for human consumption regarding metal content. These findings emphasize the role of local environmental and industrial factors in influencing metal bioaccumulation in marine ecosystems. Genetic and ecological dynamics, such as the Almería-Oran Front and the Canary Islands' isolation, likely contribute to these patterns. The study underscores the importance of continuous monitoring to safeguard food safety and marine ecosystem health. Despite Cartagena's elevated contamination levels, which pose a higher potential risk if sardine consumption is frequent, sardines from all locations remain within safety limits. Moving forward, research should prioritize long-term monitoring and explore genetic and ecological factors influencing bioaccumulation trends, contributing to sustainable management and effective pollution control measures. This highlights the interconnectedness of environmental health and human dietary safety, emphasizing the need for a proactive approach to monitoring marine contamination.

In vitro bioaccessibility of inorganic and organic copper in different diets

In poultry diets, copper is an essential nutrient that is critical for various physiological functions. Although copper sulfate is commonly used due to its cost-effectiveness, organic copper sources are gaining popularity because of their superior production outcomes and environmental benefits. Nevertheless, understanding the distinct bioaccessibility of inorganic and organic copper in diverse dietary setting remains limited. This study investigated the bioaccessibility of copper sulfate, copper amino acid chelate, and copper proteinate in the intestine via in vitro digestion and in situ dialysis. The results showed significant differences in the molecular size distribution of compounds formed by different copper salts within the intestinal environment, thereby leading to varying bioaccessibility. Copper sulfate has a bioaccessibility of 47 % ± 4%, which is significantly lower than copper amino acid chelate and copper proteinate (63% ± 5%, and 60% ± 4%, respectively) in purified diet systems. Similarly, in whey protein systems, sulfate records 54% ± 10% bioaccessibility compared to 78% ± 9% and 76% ± 5% for copper amino acid chelate and copper proteinate. Coexisting feed ingredients have a significant impact on copper bioaccessibility. Copper sulfate forms precipitates, reducing its bioaccessibility to 34% ± 1% in sodium nitrate solution. The addition of digestive enzyme increases the bioaccessibility of copper sulfate to 81% ± 2% by providing organic ligands. Digestive enzyme also enhanced the bioaccessibility of copper proteinate from 36% ± 4% to 81% ± 4% by degrading its ligands. However, feed ingredients may decrease copper bioaccessibility by forming macromolecular complexes with copper, as all the organic ligands can competitively bind with copper in the intestine. These findings emphasize the importance of considering copper salt types and diet composition in animal nutrition practices.

Elements in Serum, Muscle, Liver, and Kidney of Rabbits Fed Macroalgae-Supplemented Diets

The addition of marine macroalgae to animal feed has garnered interest due to the demonstrated benefits of gut health in many livestock species. Most macroalgae have a higher mineral content than terrestrial vegetables, making them an attractive, sustainable source of minerals. However, some macroalgae contain elevated concentrations of iodine and arsenic, which may be transferred to the meat of livestock fed with macroalgae. This study evaluated the mineral profile of rabbit serum, muscle, liver, and kidney of rabbits fed diets supplemented with different marine macroalgae, with the goal of improving post-weaning gut health and reducing reliance on antibiotics. We found increased deposition of iodine in muscle, liver, and kidney due to macroalgae supplementation, which is particularly promising for regions with low iodine endemicity. Higher, though relatively low arsenic concentrations, compared to those in other animal meats and food sources, were also detected in the muscle, liver, and kidney of macroalgae-fed rabbits. The absence of apparent interactions with other micronutrients, particularly selenium, suggests that the inclusion of macroalgae in rabbit diets will not affect the overall mineral content. Enhanced bioavailability of elements such as phosphorus and iron may provide additional benefits, potentially reducing the need for mineral supplementation.

In Vitro Evaluation of Bioavailability of Cr from Daily Food Rations and Dietary Supplements from the Polish Market

Only some of the nutrients consumed with food are able to be absorbed from the gastrointestinal (GI) tract and enter the systemic circulation (blood). Because some elements are essential minerals for humans, their beneficial effect on the body depends significantly on their bioavailable amount (the fraction that can be absorbed and used by the organism). The term bioavailability, which is very often used to describe the part of nutrients that is able to be absorbed, is influenced by various factors of exogenous and endogenous origin. The main purpose of the study was to assess the relative bioavailability of Cr from selected dietary supplements in the presence of various types of diets, which significantly influence the level of bioavailability. The research was performed using a previously developed and optimized two-stage in vitro digestion model using cellulose dialysis tubes of food rations with the addition of pharmaceutical products. Cr was determined using the ICP-OES and GF-AAS methods, depending on its concentration in particular fractions. The determined relative bioavailability ranged between 2.97 and 3.70%. The results of the study revealed that the type of diet, the chemical form of the molecule, and the pharmaceutical form of preparations have a significant influence on the bioavailability of Cr.

Metal content in Sardina pilchardus during the period 2014-2022 in the Canary Islands (Atlantic EC, Spain)

The contamination present in an organism varies depending on biological and oceanographic conditions, so monitoring the same species is of great importance to understand the state of the ecosystem. Fifteen specimens in Sardina pilchardus between 12 and 15 cm in total length were collected during the second half of January of each of the study years (2014, 2016, 2018, 2020 and 2022). Samples were analyzed with Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) to measure metals (Al, Cd, Cu, Fe, Li, Ni, Pb and Zn) in mg/Kg. There was a progressive decrease in Pb content over the period, with the highest concentration being obtained in 2014 (0.086 ± 0.065 mg/kg). Locally important oceanic-atmospheric events may occur in the study period that strongly impact the tissue composition of marine organisms. In this case, discontinuous trends were evident in some of the metal concentrations analyzed in the muscle of European sardine in the Canary Islands.

Influence of Diet on the Bioavailability of Active Components from Zingiber officinale Using an In Vitro Digestion Model

Ginger (Zingiber officinale Rosc.) is a plant known all over the world that is used as a spice and as an ingredient in drinks, dietary supplements, and cosmetics. The growing availability of its fresh rhizomes makes it even more likely to be used in the diet, mainly due to its beneficial health properties and high content of polyphenols (gingerols and shogaols). The main goal and motivation of the authors was to assess the bioavailability of active substances contained in the extract from ginger rhizomes in the presence of various types of diets using the in vitro digestion method, enabling simulation of the processes occurring during the digestion and absorption of metabolites in the small intestine. For the qualitative and quantitative analyses, the HPLC-MS (High Performance Liquid Chromatography-Mass Spectrometry) and HPLC (High Performance Liquid Chromatography) techniques were used, respectively. Based on the obtained results, it was found that the best bioavailability of the selected ginger polyphenols (6-gingerol, 8-gingerdione, 8-shogaol, and 10-gingerdione) was estimated for a high-fiber diet, while the weakest results were obtained for standard and basic diets. In the case of the high-fiber diet, the bioavailability of the mentioned compounds was estimated as 33.3, 21.4, 6.73, and 21.0%, while for the basic diet, it was only 21.3, 5.3, 2.0, and 1.0%, respectively.

Rehashing Our Insight of Seaweeds as a Potential Source of Foods, Nutraceuticals, and Pharmaceuticals

In a few Southeast Asian nations, seaweeds have been a staple of the cuisine since prehistoric times. Seaweeds are currently becoming more and more popular around the world due to their superior nutritional value and medicinal properties. This is because of rising seaweed production on a global scale and substantial research on their composition and bioactivities over the past 20 years. By reviewing several articles in the literature, this review aimed to provide comprehensive information about the primary and secondary metabolites and various classes of bioactive compounds, such as polysaccharides, polyphenols, proteins, and essential fatty acids, along with their bioactivities, in a single article. This review also highlights the potential of seaweeds in the development of nutraceuticals, with a particular focus on their ability to enhance human health and overall well-being. In addition, we discuss the challenges and potential opportunities associated with the advancement of pharmaceuticals and nutraceuticals derived from seaweeds, as well as their incorporation into different industrial sectors. Furthermore, we find that many bioactive constituents found in seaweeds have demonstrated potential in terms of different therapeutic attributes, including antioxidative, anti-inflammatory, anticancer, and other properties. In conclusion, seaweed-based bioactive compounds have a huge potential to play an important role in the food, nutraceutical, and pharmaceutical sectors. However, future research should pay more attention to developing efficient techniques for the extraction and purification of compounds as well as their toxicity analysis, clinical efficacy, mode of action, and interactions with regular diets.

A new evaluation system of iron bioavailability in seaweed

In marine ecosystems, the avid binding of iron (Fe) to organic ligands influences Fe bioavailability in seaweed. This study aimed to elucidate Fe's biological availability to seaweed and develop a simple and rapid bioassay method as a new evaluation system. Undaria pinnatifida was used as a model seaweed species and the actual seaweed samples were collected using the 0.5 m × 0.5 m quadrat from the Mashike Bay area of Hokkaido, Japan. Chlorophyll fluorescence measurements were utilized as an index to evaluate the biological -effectiveness of Fe and compared with the results of culture tests based on growth. The effect of Fe content on media, pre-culture, concentrations and types of chelating and reducing agents in clearing solutions, cleaning time, Fe removal effect, and resistance to seaweed were systematically optimized to obtain the maximum efficacy of the washing solution. A bioassay was developed to evaluate the Fe environment by combining chlorophyll fluorescence measurements. The findings suggest that the tolerance of seaweeds to the wash solution is strongly influenced by the concentrations of the chelating and reducing agents than their types. Washing with 0.02 M Ti-Citrate/EDTA solution for 80 s was the most effective in terms of maximum Fe removal with minimum cell damage. The application of pre-culture and chemical pre-treatment methods under Fe deficiency to the culture strain confirmed the maximum reproducibility in the culture test. Finally, the developed method was applied to actual seaweed samples and was found to be applicable to many seaweed species. However, the method was less robust for some seaweed species and depended on the seaweed growth stage.

In Vitro Evaluation of Bioavailability of Se from Daily Food Rations and Dietary Supplements

Bioavailability refers to a fraction of a substance that is potentially absorbed from the gastrointestinal tract and enters the systemic circulation (blood). This term is related to various substances, including minerals, that are present in a complex matrix of food which is consumed every day as natural products and pharmaceutical preparations, e.g., dietary supplements. The purpose of the study was to assess the bioavailability of Se from selected dietary supplements, with the simultaneous assessment of the effect the diet type (standard, basic and high-residue diets) has on relative bioavailability. The research included a two-stage in vitro model of digestion using cellulose dialysis tubes of the food rations with the addition of dietary supplements. Se was determined using the ICP-OES method. The bioavailability of Se from dietary supplements, in the presence of food matrix, was determined to be within the range of 19.31-66.10%. Sodium selenate was characterized by the highest value of this parameter, followed by organic forms and sodium selenite. The basic diet, characterized by moderate protein and high carbohydrate and fiber contents, positively influenced the bioavailability of Se. The bioavailability of Se was also influenced by the pharmaceutical form of the product-the highest was for tablets, followed by capsules and coated tablets.

Effects of Marine Bioactive Compounds on Gut Ecology Based on In Vitro Digestion and Colonic Fermentation Models

Digestion and the absorption of food compounds are necessary steps before nutrients can exert a role in human health. The absorption and utilization of nutrients in the diet is an extremely complex dynamic process. Accurately grasping the digestion and absorption mechanisms of different nutrients or bioactive compounds can provide a better understanding regarding the relationship between health and nutrition. Several in vitro models for simulating human gastrointestinal digestion and colonic fermentation have been established to obtain more accurate data for further understanding of the metabolism of dietary components. Marine media is rich in a wide variety of nutrients that are essential for humans and is gaining increased attention as a research topic. This review summarizes some of the most explored in vitro digestion and colonic fermentation models. It also summarizes the research progress on the digestion and absorption of nutrients and bioactive compounds from marine substrates when subjected to these in vitro models. Additionally, an overview of the changes imparted by the digestion process on these bioactive compounds is provided, in order to support those marine resources that can be utilized for developing new healthy foods.

Toxic and Trace Elements in Seaweeds from a North Atlantic Ocean Region (Tenerife, Canary Islands)

Canary Islands is a North Atlantic Ocean archipelago in the Macaronesian region that stand out for its great algae diversity and its climatic conditions. However, even in this low industrialised area, human activities tend to increase the marine pollution. Asparagopsis spp. and Liagora spp. algae are red algae frequent in the Canary Islands’ coasts. Therefore, they could be used as bio-indicators of marine pollution for trace elements. A total of 30 samples of both algae’s species from Tenerife’s southern coast, specifically in Playa Grande, Porís de Abona, in Arico (Tenerife, Spain) were used to determine trace element content (Mn, B, Ba, Cu, Cd, Co, Fe, Li, Mo, Ni, Pb, Sr, V, Zn, Al, Cr) through inductively coupled plasma atomic emission spectroscopy (ICP—OES). Highest Fe concentrations were found in Liagora spp. concentrations (1190 ± 1545 mg/kg dw) and Al (288 ± 157 mg/kg dw) was more significant in Asparagopsis spp. High concentrations of B were also registered in both species 80.2 ± 34.2 mg/kg dw and 77.9 ± 34.2 mg/kg dw, respectively. The recorded concentrations show a high contamination scenario in the collected area. Porís is known by its marine diversity and by its higher pollution levels, compared with other locations of Tenerife, due to the currents present on the Canary Island and its singular north orientation, actions must be taken to reduce pollution.

In situ analysis of copper speciation during in vitro digestion: Differences between copper in drinking water and food

In recent years, the safety of copper in drinking water has increasingly been questioned. Copper speciation is an important factor that affects its bioavailability and toxicity; thus, it is critical to investigate the speciation of copper that is ingested from food and drinking water during in vitro digestion. After digestion, water- and food-derived copper formed 60 ± 4% 0.1-1 kDa and 49 ± 6% 10-1,000 kDa copper complexes, respectively. Under simulated fasting drinking water conditions, up to 90 ± 2% 0.1-1 kDa copper complexes formed. In addition, using ion selective electrode analysis, water-derived copper was detected that contained higher Cu²⁺ concentrations after digestion than those of food-derived copper. These results indicate that water-derived copper forms smaller-sized species and exhibits higher Cu²⁺ concentrations during digestion than those of food-derived copper, thereby highlighting the importance of reassessing the safety limit for copper in drinking water.

The influence of gastrointestinal pH on speciation of copper in simulated digestive juice

Speciation can provide knowledge about absorption, reactivity to binding sites, bioavailability, toxicity, and excretion of elements. In this study, the speciation of copper in different model solutions under the influence of gastrointestinal (GI) pH was studied by ion selective electrode (ISE) and inductively coupled plasma optical emission spectrometry (ICP OES). It was found that the electrode response (mV) against Cu2+ decreased with the increase in pH and dropped to the lowest point at pH 7.5 in all model solutions. When amino acids and organic acids were present, the ratio of filtered copper (0.45 μm, pH 7.5) was more than 90%. When casein was present, whey protein, pancreatin, and starch were added, and the ratio of filtered copper was 85.6 ± 0.3, 56.7 ± 8.8, 38.5 ± 5.1, and 1.0 ± 0.3%, respectively. When there is not enough organic ligand, excessive copper will form copper hydroxide precipitation with the increase in pH, but it got the highest electrode response (mV) against Cu2+. From this study, it can be concluded that the speciation of copper in GI tract is strongly influenced by the pH and the composition of food. When there are few ligands coexisting in the GI tract, the concentration of copper ion may be relatively high.

In vitro assessment of major and trace element bioaccessibility in tea samples

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.

Seasonal and ontogenic variations of metal content in the European pilchard (Sardina pilchardus) in northwestern African waters

Marine fishes are exposed to great human-induced alterations due to the indiscriminate discharges into the sea, increasing marine pollution. For this study, 324 specimens of Sardina pilchardus from the Canary Islands were analized during a period of 2 years (June 2016 to May 2018). The concentration of 11 metals and trace elements (Al, B, Cd, Cr, Cu, Fe, Li, Ni, Pb, V and Zn) was determined in each individual using the Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) technique. Statistical analyses were carried out considering the following factors: oceanographic season, maturity of the gonads in the seasons, size of the specimens. Sardina pilchardus specimens captured in the hot season presented higher Ni, Li and Pb levels than the specimens caught in the cold season. Immature specimens had higher concentration in more metals than the mature specimens. This fact may be due to the fact that these specimens require a much higher metabolic rate due to their growth and do not detoxify like mature specimens. Significant differences were found in the concentration of metals in all the analyzes performed.

Risks of consuming cadmium-contaminated shellfish under seawater acidification scenario: Estimates of PBPK and benchmark dose

We aim to assess the risks of renal dysfunction and osteoporosis that is attributed to the seawater acidification caused cadmium (Cd) level increase in human consumed shellfish. A physiology-based pharmacokinetic model was used to estimate Cd concentrations in urine and blood among shellfish-only consumers and among the general population. We used the benchmark dose (BMD) method to determine the threshold limits of Cd in urine for renal dysfunction and in blood for osteoporosis for assessing the human health risk. Our results revealed that seawater acidification could increase the Cd accumulation in shellfish by 10-13% compared to the situations under current pH levels. Under the lower seawater pH level, the daily intake of Cd could increase by 21%-67% among shellfish-only consumers, and by 13%-17% among the general population. Our findings indicated that seawater acidification would lead to a marginal increase in Cd intake among humans in shellfish-only consumers. The results of BMDs of urinary Cd showed that the threshold limits for renal dysfunction at 5% were 3.00 μg g^-1 in males and 12.35 μg g^-1 in females. For osteoporosis, the estimated BMDs of blood Cd were 7.95 μg L^-1 in males and 1.23 μg L^-1 in females. These results of the risk of Cd intake showed that the consumption of Cd-contaminated shellfish in the general population is largely unaffected by changes in seawater pH levels. Notably, the potential impact of seawater acidification on renal dysfunction for males in shellfish-only consumers face a 14% increase of risk.

Seaweed Potential in the Animal Feed: A Review

Seaweed (known as marine algae) has a tradition of being part of the animal feed in the coastal areas, from ancient times. Seaweeds, are mixed with animal feed, because when consumed alone can have negative impact on animals. Thus, seaweeds are very rich in useful metabolites (pigments, carotenoids, phlorotannins, polyunsaturated fatty acids, agar, alginate and carrageenan) and minerals (iodine, zinc, sodium, calcium, manganese, iron, selenium), being considered as a natural source of additives that can substitute the antibiotic usage in various animals. In this review, we describe the nutritional values of seaweeds and the seaweed effects in the seaweed-based animal feed/supplements.

Bioaccumulation and health risk assessment of trace metals in fish from freshwater polyculture ponds in Chengdu, China

The freshwater polyculture pond culturing occupied an important position in the aquaculture industry. Accumulation of trace metals was investigated in water, sediments, and fish (Carassius auratus, Cyprinus carpio, Ctenopharyngodon idellus) from typical polyculture ponds in Chengdu, China. The results showed most of the pond water in Chengdu were safe for fish cultivation. The Cd and Cr concentrations in sediment samples from sites S3, S4, and S9 which were near the industrial park and road with a high traffic volume were higher than those of the other sites. Cu, Cr, Fe, Zn, Mn, Ni, and Pb in sediments were unpolluted, while Cd was unpolluted to moderately polluted due to anthropogenic activities. Cu, Cd, and Pb in fish pond sediment of Chengdu had higher potential mobility under normal environmental circumstances. The trace metal concentrations in liver of three fish species were all higher than those in muscle tissues. The order of bioaccumulation factor (BAF) values for trace metals was Cr > Cu > Pb > Zn > Cd > Ni > 20. The concentrations of Cu, Cd, Pb, Zn, and Cr in the muscle of three fish species were all below the local and international maximum permissible levels. The target hazard quotient (THQ) and hazard index (HI) of trace metals in aquaculture fish ponds in Chengdu were lower than 1, which indicated that the consumption of grass, crucian, and common carp cultivated in the aquaculture ponds of Chengdu pose no health risk to the residents.

Nutritional status affects the bioaccessibility and speciation of arsenic from soils in a simulator of the human intestinal microbial ecosystem

Arsenic (As) is a highly toxic contaminant in food and soil. In this study, we investigated the effects of four nutritional states (including a fed state with vitamin C, a fed state with protein powder, a fed state with glucose and a fasted state) on the variability of soil As bioaccessibility and biotransformation using the physiologically based extraction test (PBET) combined with a simulator of the human intestinal microbial ecosystem model (SHIME). The results indicated that the vitamin C and protein powder increased As bioaccessibility in gastric digests. In the colon phase, As bioaccessibility was observably enhanced by protein powder, and it varied under the vitamin C and glucose conditions. Additionally, the order of As methylation percentages in the four nutritional states was protein powder > vitamin C > fasted state > glucose (except S2); As bioaccessibility increased 1.3-13.7% and 15.8-35.4% in treatments of the vitamin C and protein powder, respectively. Meanwhile, large amounts of monomethylarsonic acid (MMA^V) were observed in the colon digest in the protein powder condition. In contrast, As methylation was significantly decreased with the addition of glucose, with a decline of 25.9-45.5%. Additionally, glucose enhanced the reduction of As(V). Therefore, nutritional status is a crucial parameter for the prediction of bioaccessibility and speciation of As when assessing health risks from As following oral exposure.

Minerals from Macroalgae Origin: Health Benefits and Risks for Consumers

Seaweeds are well-known for their exceptional capacity to accumulate essential minerals and trace elements needed for human nutrition, although their levels are commonly very variable depending on their morphological features, environmental conditions, and geographic location. Despite this variability, accumulation of Mg, and especially Fe, seems to be prevalent in Chlorophyta, while Rhodophyta and Phaeophyta accumulate higher concentrations of Mn and I, respectively. Both red and brown seaweeds also tend to accumulate higher concentrations of Na, K, and Zn than green seaweeds. Their valuable mineral content grants them great potential for application in the food industry as new ingredients for the development of numerous functional food products. Indeed, many studies have already shown that seaweeds can be used as NaCl replacers in common foods while increasing their content in elements that are oftentimes deficient in European population. In turn, high concentrations of some elements, such as I, need to be carefully addressed when evaluating seaweed consumption, since excessive intake of this element was proven to have negative impacts on health. In this regard, studies point out that although very bioaccessible, I bioavailability seems to be low, contrarily to other elements, such as Na, K, and Fe. Another weakness of seaweed consumption is their capacity to accumulate several toxic metals, which can pose some health risks. Therefore, considering the current great expansion of seaweed consumption by the Western population, specific regulations on this subject should be laid down. This review presents an overview of the mineral content of prevalent edible European macroalgae, highlighting the main factors interfering in their accumulation. Furthermore, the impact of using these marine vegetables as functional ingredients or NaCl replacers in foods will be discussed. Finally, the relationship between macroalgae’s toxic metals content and the lack of European legislation to regulate them will be addressed.

In vitro human bioavailability of major, trace and ultra-trace elements in Chilean ‘natural’ wines from Itata Valley

In vitro human bioavailability of elements in ‘natural’ wines from Chile's Itata Valley has been assessed using an in vitro dialyzability approach.

Oral bioaccessibility of toxic and essential elements in raw and cooked commercial seafood species available in European markets

The oral bioaccessibility of several essential and toxic elements was investigated in raw and cooked commercially available seafood species from European markets. Bioaccessibility varied between seafood species and elements. Methylmercury bioaccessibility varied between 10 (octopus) and 60% (monkfish). Arsenic (>64%) was the toxic element showing the highest bioaccessibility. Concerning essential elements bioaccessibility in raw seafood, selenium (73%) and iodine (71%) revealed the highest percentages. The bioaccessibility of elements in steamed products increased or decreased according to species. For example, methylmercury bioaccessibility decreased significantly after steaming in all species, while zinc bioaccessibility increased in fish (tuna and plaice) but decreased in molluscs (mussel and octopus). Together with human exposure assessment and risk characterization, this study could contribute to the establishment of new maximum permissible concentrations for toxic elements in seafood by the European food safety authorities, as well as recommended intakes for essential elements.

Algae as nutritional and functional food sources: revisiting our understanding

Global demand for macroalgal and microalgal foods is growing, and algae are increasingly being consumed for functional benefits beyond the traditional considerations of nutrition and health. There is substantial evidence for the health benefits of algal-derived food products, but there remain considerable challenges in quantifying these benefits, as well as possible adverse effects. First, there is a limited understanding of nutritional composition across algal species, geographical regions, and seasons, all of which can substantially affect their dietary value. The second issue is quantifying which fractions of algal foods are bioavailable to humans, and which factors influence how food constituents are released, ranging from food preparation through genetic differentiation in the gut microbiome. Third is understanding how algal nutritional and functional constituents interact in human metabolism. Superimposed considerations are the effects of harvesting, storage, and food processing techniques that can dramatically influence the potential nutritive value of algal-derived foods. We highlight this rapidly advancing area of algal science with a particular focus on the key research required to assess better the health benefits of an alga or algal product. There are rich opportunities for phycologists in this emerging field, requiring exciting new experimental and collaborative approaches.

Food wastes as fish feeds for polyculture of low-trophic-level fish: bioaccumulation and health risk assessments of heavy metals in the cultured fish

The major purpose of this study was to use different types of food wastes which serve as the major sources of protein to replace the fish meal used in fish feeds to produce quality fish. Two types of food waste-based feed pellets FW A (with cereals) and FW B (with cereals and meat products) and the commercial feed Jinfeng® were used to culture fingerlings of three low-trophic-level fish species: bighead carp, grass carp, and mud carp (in the ratio of 1:3:1) for 1 year period in the Sha Tau Kok Organic Farm in Hong Kong. Heavy metal concentrations in all of the fish species fed with food waste pellets and commercial pellets in Sha Tau Kok fish ponds were all below the local and international maximum permissible levels in food. Health risk assessments indicated that human consumption of the fish fed with food waste feed pellets was safe for the Hong Kong residents. The present results revealed that recycling of food waste for cultivating low-trophic-level fish (mainly herbivores and detritus feeders) is feasible, and at the same time will ease the disposal pressure of food waste, a common problem of densely populated cities like Hong Kong.

Trace metal determination as it relates to metallosis of orthopaedic implants: Evolution and current status

In utilising metal surfaces that are in constant contact with each other, metal-on-metal (MoM) surgical implants present a unique challenge, in the sense that their necessity is accompanied by the potential risk of wear particle generation, metal ion release and subsequent patient toxicity. This is especially true of orthopaedic devices that are faulty and subject to failure, where the metal surfaces undergo atypical degradation and release even more unwanted byproducts, as was highlighted by the recent recall of orthopaedic surgical implants. The aim of this review is to examine the area of metallosis arising from the wear of MoM articulations in orthopaedic devices, including how the surgical procedures and detection methods have advanced to meet growing performance and analytical needs, respectively.

Risk assessments of human exposure to bioaccessible phthalate esters through market fish consumption

The bioaccessibility of phthalate esters in 20 fish species collected from Hong Kong market was evaluated using an in vitro gastrointestinal model. The ∑phthalate ester concentration detected in fresh water fish ranged from 1.66 to 3.14μg/g wet weight (ww) and in marine fish ranged from 1.57 to 7.10μg/g ww, respectively. di-2-Ethylhexyl phthalate (DEHP) and di-n-butyl phthalate (DBP) were the predominant compounds in both freshwater fish and marine fish. The digestible concentrations of phthalate esters ranged from 0.20 to 1.23μg/g ww (mean 0.35μg/g ww), and account for 2.44 to 45.5% (mean 16.8%) for raw concentrations of phthalate esters. In the present study, the accumulation ratio Rnn value of all phthalate esters was greater than 1 except for diisobutyl phthalate (DIBP), DBP and di-n-hexyl phthalate (DHP), suggesting that these phthalate esters could be accumulated during gastrointestinal digestion. Based on this health risk assessment, most of fish species were considered safe for consumption, however Hong Kong residents should take caution when consuming Mud carp and Bighead carp.

Bioaccessibility of metals in fish, shellfish, wild game, and seaweed harvested in British Columbia, Canada

Fish, shellfish, wild game, and seaweed are important traditional foods that are essential to the physical and cultural well-being of Indigenous peoples in Canada. The goal of this study was to measure the concentration and bioaccessibility of As, Cd, Hg, Se, Cu and Mn in 45 commonly consumed traditional foods collected by harvested by the First Nations Food, Nutrition, and Environment Study (FNFNES) from 21 First Nations communities in British Columbia, Canada, in 2008-2009. A significant and negative correlation was observed between Hg concentration and Hg bioaccessibility. Metal bioaccessibility tended to be high; median values ranging between 52% (Mn) and 83% (Cu). The notable exceptions were observed for As in wild game organs (7-19%) and rabbit meat (4%) as well as Hg in salmon eggs (10%). Results of Principal Components Analysis confirmed the unique pattern of bioaccessibility of As and Hg in traditional foods, suggesting that, unlike other metals, As and Hg bioaccessibility are not simply controlled by food digestibility under the operating conditions of the in vitro model. These data provide useful information for dietary contaminant risk assessment and intake assessments of essential trace elements.