Bioavailability Of Iodine Research Articles

Iodine Bioavailability and Biochemical Effects of Brassica oleracea var. sabellica L. Biofortified with 8-Hydroxy-7-iodo-5-quinolinesulfonic Acid in Wistar Rats

Background: Iodine is one of the essential trace elements for human life. The main objective of the biofortification of plants with iodine is to obtain food with a higher content of this element compared to conventional food. Biofortification of plants with iodine can increase the intake of this trace element by different populations. In addition, it may reduce the risk of iodine deficiency diseases. Objectives: The aim of the study was to investigate the effect of kale biofortified with 8-hydroxy-7-iodo-5-quinolinesulfonic acid (8-OH-7-I-5QSA) on iodine bioavailability and biochemical effects in Wistar rats. Methods: Kale biofortified with (8-OH-7-I-5QSA) was tested for iodine levels in urine, feces, and selected tissues using the ICP-MS/MS technique. The feeding experiment was designed to investigate potential changes in selected thyroid-regulated biochemical parameters in blood serum of Wistar rats. Results: The dietary intake of Wistar rats fed kale biofortified with (8-OH-7-I-5QSA) from both the “Oldenbor F1” and “Redbor F1” cultivars for 8 weeks resulted in significantly (p ≤ 0.05) higher iodine concentrations in the urine and kidneys of rats, which proves iodine bioavailability. Rats’ diets with “Oldenbor F1” and “Redbor F1” kale non- and -biofortified with 8-OH-7-I-5QSA had a significantly (p ≤ 0.05) lower or a tendency for lower concentration of TSH, triglyceride, total and direct bilirubin, TBARs, uric acid, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations in serum. Dietary intake of “Oldenbor F1” and “Redbor F1” kale biofortified with 8-OH-7-I-5QSA significantly (p ≤ 0.05) increased the total antioxidant status (TAS). Conclusions: Our study confirms that kale biofortified with iodine in organic form iodoquinoline 8-OH-7-I-5QSA is bioavailable and well absorbed by the Wistar rat and has a positive effect on selected biochemical parameters. The results obtained in this study may be highly predictive for further studies in humans.

Evaluation of the Bioavailability of Iodine and Arsenic in Raw and Cooked Saccharina japonica Based on Simulated Digestion/Caco-2 Cell Model.

Kelp is a traditional healthy food due to its high nutritional content; however, its relatively high contents of iodine and arsenic have raised concerns about its edible safety. This study explored the effects of different cooking treatments on the contents of iodine and arsenic in kelp, evaluated the bioaccessibility and bioavailability of iodine and arsenic in kelp using in vitro digestion, and compared the differences in the transport characteristics of iodine in kelp and KIO3 using a Caco-2 monolayer cell transport model. The results show that the content of target elements that reached systemic circulation could be reduced by cooking and gastrointestinal digestion. The highest reductions in iodine and arsenic were 94.4% and 74.7%, respectively, which were achieved by boiling for 10 min. The bioaccessibility and bioavailability of iodine and arsenic were significantly improved by a cooking treatment. However, the contents of iodine and arsenic decreased significantly, with the bioaccessibility of iodine reducing from 3188.2 μg/L to 317.0 μg/L and that of arsenic reducing from 32.5 μg/L to 18.1 μg/L in the gastric phase after boiling. The findings also show that the efficiency of iodine transport in kelp and KIO3 was positively correlated with the transport time and negatively correlated with the concentration of iodine. With the increase in the iodine concentration, the rate of iodine transport in kelp decreased from 63.93% to 3.14%, but that of KIO3 was stable at around 35%, which indicates that the absorption efficiency of iodine from kelp was limited, even when too much kelp was ingested. In conclusion, the edible safety of kelp is significantly improved after cooking. The risk of excessive iodine and arsenic intake caused by consuming kelp is extremely low, and as an effective iodine supplement source, kelp has higher edible safety compared with KIO3. This study clarifies the safety of algae based on iodine and arsenic contents and also provides a basis for the formulation of food safety standards.

Goiter, iodine bioavailability and intrauterine growth restriction in Indigenous and Afro-descendant pregnant women from six non-metropolitan areas of Colombia (2019-2020).

Iodine is an essential mineral for fetal growth and brain development. The aim of this research was to evaluate goiter, iodine deficiency and intrauterine growth restriction in pregnant women of minority ethnic groups in Colombia. A cross-sectional study was performed in six non-metropolitan areas of Colombia. A total of 318 Indigenous and Afro-descendant pregnant women were invited to participate: 248 (83.2%) Indigenous and 50 (16.8%) Afro-descendants were studied. The mean age was 24 years (range 13-44 years). Of the women, 130 (43.5%) were from the department of Cauca, 72 (24.1%) were from C&oacute;rdoba, 28 (9.4%) were from Guajira, 26 (8.8%) were from Sierra Nevada de Santa Marta, 22 (7.4%) were from Amazonas, 16 (5.4%) were from Meta and 4 (1.3%) were from the department of Cesar. A total of 244 (81.8%) were illiterate and 291 (97.7%) were of very low socioeconomic level. Goiter was observed in 69 (23.3%) pregnant women (38 (41.7%) from the department of Cauca, 10 (35.7%) from Guajira, 5 (31.2%) from Meta, 6 (27.2%) from Amazonas and 10 (13.8%) from C&oacute;rdoba). Iodine deficiency (<100 &micro;g/L) was observed in 42 (14.9%) pregnant women (16 (11.6%) mild (50-99 &micro;g/L), 19 (13.8%) moderate (20-49 &micro;g/L) and 7 (5.1%) severe (<20 &micro;g/L)). Being literate was a protective factor for iodine deficiency (odds ratio (OR)=0.19, 95% confidence interval (CI) 0.04-0.84, p=0.016). Being illiterate and iodine deficient was only a risk factor for goiter (OR=6.72, 95%CI 3.9-9.5, p=0.038) in the department of Cauca. A high prevalence of goiter, iodine deficiency and intrauterine growth restriction was observed in minority ethnic groups of Colombia. The highest prevalence and risk was observed in the department of Cauca.

Total Iodine Quantification and In Vitro Bioavailability Study in Abalone (Haliotis discus hannai) Using Inductively Coupled Plasma Mass Spectrometry.

The aim of this study is to determine the total iodine content in Korean abalone (Haliotis discus hannai) and to investigate the bioavailability of iodine using an in vitro method. This research paper focuses on total iodine quantification in abalone (Haliotis discus hannai) and its components (viscera and muscle) using inductively coupled plasma mass spectrometry (ICP-MS). Additionally, an in vitro bioavailability study explored iodine absorption potential. Abalone pretreatment involved both the European standard method (ES) and microwave-assisted extraction method (MAE). The limits of detection (LOD) were 0.11 ng/g for both ES and MAE, with a limit of quantification (LOQ) of 5.4 ng/g for MAE. Accuracy, assessed using a reference material (fish muscle, ERM-BB422), showed values of 1.5 ± 0.010 mg/kg for ES and 1.6 ± 0.066 mg/kg for MAE, within an acceptable range of 1.4 ± 0.42 mg/kg. Precision, evaluated using the Horwitz ratio (HorRat) with a reference material, was determined to be 0.45 for ES and 0.27 for MAE. Therefore, total iodine contents were estimated as 74 ± 2.2 µg/g for abalone viscera and 17 ± 0.77 µg/g for abalone muscle with ES, and 76 ± 1.0 µg/g for abalone viscera and 17 ± 0.51 µg/g for abalone muscle with MAE. Recovery tests demonstrated an acceptable range of 90-110%. In the in vitro bioavailability assessment, digestion efficiency yielded ranges of 42-50.2% for viscera and 67-115% for muscle. Absorption efficiency variations were determined as 37-43% for viscera and 48-75% for muscle.

Climate changes affecting global iodine status.

Global warming is now universally acknowledged as being responsible for dramatic climate changes with rising sea levels, unprecedented temperatures, resulting fires and threatened widespread species loss. While these effects are extremely damaging, threatening the future of life on our planet, one unexpected and paradoxically beneficial consequence could be a significant contribution to global iodine supply. Climate change and associated global warming are not the primary causes of increased iodine supply, which results from the reaction of ozone (O3) arising from both natural and anthropogenic pollution sources with iodide (I-) present in the oceans and in seaweeds (macro- and microalgae) in coastal waters, producing gaseous iodine (I2). The reaction serves as negative feedback, serving a dual purpose, both diminishing ozone pollution in the lower atmosphere and thereby increasing I2. The potential of this I2 to significantly contribute to human iodine intake is examined in the context of I2 released in a seaweed-abundant coastal area. The bioavailability of the generated I2 offers a long-term possibility of increasing global iodine status and thereby promoting thyroidal health. It is hoped that highlighting possible changes in iodine bioavailability might encourage the health community to address this issue.

Curly Kale (Brassica oleracea var. Sabellica L.) Biofortified with 5,7-Diiodo-8-quinolinol: The Influence of Heat Treatment on Iodine Level, Macronutrient Composition and Antioxidant Content.

Many disorders are a result of an inadequate supply of macronutrients and micronutrients in the diet. One such element is iodine. This study used curly kale (Brassica oleracea var. Sabellica L.) biofortified with the 5,7-diiodo-8-quinolinol iodine compound. The effect of the heat treatment on the chemical composition of the curly kale was studied. In addition, iodine bioavailability was evaluated in in vivo studies. Our investigation showed that iodine loss depends on the type of heat treatment as well as on the variety of kale. Curly kale biofortified with iodoquinoline had significantly higher iodine levels after thermal processing (steaming, blanching, boiling) than the vegetable biofortified with KIO3. Generally, steaming was the best thermal processing method, as it contributed to the lowest iodine loss in curly kale. The red variety of kale, 'Redbor F1', showed a better iodine stability during the heat treatment than the green variety, 'Oldenbor F1'. The thermal treatment also significantly affected the dry matter content and the basic chemical composition of the tested varieties of the 5,7-diI-8-Q biofortified kale. The steaming process caused a significant increase in total carbohydrates, fiber, protein and crude fat content ('Oldenbor F1', 'Redbor F1'), and antioxidant activity ('Oldenbor F1'). On the other hand, boiling caused a significant decrease, while steaming caused a significant increase, in protein and dry matter content ('Oldenbor F1', 'Redbor F1'). The blanching process caused the smallest significant decrease in ash compared to the other thermal processes used ('Oldenbor F1'). A feeding experiment using Wistar rats showed that iodine from the 5,7-diI-8-Q biofortified kale has a higher bioavailability than that from the AIN-93G diet. A number of promising results have been obtained, which could form the basis for further research.

Bioavailability of iodine from a meal consisting of sushi and a wakame seaweed salad-A randomized crossover trial.

The consumption of seaweed is on the rise in the Western world. Seaweeds may contain substantial amounts of iodine, and some species could serve as a potential dietary iodine source. However, limited data on the iodine content and in vivo bioavailability of iodine from seaweeds exist. The objective was to assess whether iodine from a meal consisting of sushi with nori, (Porphyra spp) and a wakame seaweed salad (Undaria pinnatifida) had similar bioavailability as a potassium iodide reference supplement of similar iodine content. A randomized 2 × 2 crossover trial (AB/BA model) was conducted in 20 healthy young women. One intervention arm consisted of a meal with sushi and wakame salad (231 μg iodine), and the other of potassium iodide (KI) supplement (225 μg iodine). Urinary iodine concentration (UIC) was measured at 11 different time points for 48 h after the interventions. The UIC increased after consumption of both the sushi and wakame meal and the KI supplement, but the median UIC was higher after ingestion of the KI supplement. The estimated bioavailability of iodine during the first 24 h was 75% from sushi with wakame and 97% from the KI supplement. The bioequivalence analyses confirmed that the KI supplement had higher estimated bioavailability than the sushi and wakame meal, however, with small margins. Our findings on iodine bioavailability imply that sushi and wakame could be potential iodine sources in the diet, which may be favorable for population groups at risk for iodine deficiency. However, further research is needed to account for the variability of iodine content in seaweeds by different locations and degree of processing, to assure that the iodine levels are stable and predictable for the consumers.

Impact of Iodine Biofortification on Tomato Bioaccessibility through Cooking, Soaking and Simulated Digestion

Background: Even though iodine is not an essential micronutrient for the plant, it is very much needed for a person's mental and physical development. Due to the presence of negative charge on iodine it is highly susceptible to leaching. Further iodine is also highly prone to volatilization loss due to biochemical and physiochemical properties of soil leading to iodine deficiency. Agronomic biofortification of iodine is one of the ways to address iodine deficiency globally. Numerous studies have focused on the process by which plants absorb iodine from the soil, but there is still paucity of knowledge on stability of biofortified iodine in fruits. Methods: In our work, we assessed iodine bioavailability (Cooking, soaking and digestion) in tomato fruit from different sources of chitosan and potassium iodate alone and combinations using main and residual crop trials. The field experiment was carried out in Thondamuthur block of Viraliyur village at Coimbatore district of Tamil Nadu in 2021. Potassium iodate and chitosan were applied in the form of soil, foliar, and chitosan iodate complex at different stages of plant growth. Results: The results suggested that combination and potassium iodate and chitosan complex has increased the iodine stability in fruits of main crop and also retained the iodine in residual crop. As electrostatic interaction between chitosan and iodate prevents volatilization and gradually stabilizes the bioavailability of iodine in fruits. Our findings offer more details on iodine mobility and behaviour in fruits when it is used alone and combination with chitosan at different rates

Effect of chitosan iodate complex biofortification on nutrient uptake in ‘shivam’ hybrid of tomato (Solanum lycopersicum L.)

Iodine deficiency occurs when iodine levels in the soil are inadequate, resulting in limited crop uptake and, as a result, a population with insufficient iodine intake. Iodine deficiency can be avoided by biofortifying commonly consumed crops with iodine. A field experiment was conducted to investigate the effect of iodine biofortification on the nutrient uptake of fruits and plants of ‘shivam’ hybrid tomato. Potassium iodate and chitosan were applied in the form of soil, foliar, and chitosan iodate complex with control comprising 16 treatments (T1 to T16) at different stages of plant growth. Iodine accumulation in tomato fruits and plants was achieved by combining foliar and iodine chitosan forms as electrostatic interaction between chitosan and iodate prevents volatilization and gradually increases the bioavailability of iodine from soil to fruits. Biofortification of iodine throughT14- Chitosan-KIO3Complex (CsKIO3) - (SA)-10Kgha-1 + FA-KIO3-0.3% @ 60 and 90 DAT the iodine content in tomato fruit at green (0.95ppm), pink (1.01ppm) and red ripen (0.99ppm) stages of tomato and introducing it in present-day daily diet may help to reduce iodine deficiency disorder. Iodine biofortification also influenced the uptake of nitrogen, phosphorous and potassium in plants and fruits of tomatoes.

Role of different organic and inorganic amendments in the biofortification of iodine in Coriandrum sativum crop

Iodine deficiency disorder (IDDs) is one of the most prevailing and common health issues in mountainous communities. An effective way to control the prevalence and emergence of IDDs in remote areas is to use iodized salt. However, recent studies indicated that iodized salt is mostly lost during the cooking process. The current study of iodine biofortification differed from the previous studies in two main aspects: it involved exogenous organic iodine (OI), and inorganic iodine such as potassium iodide (KI), added in the amended soils, which previous studies did not consider. Moreover, the translocation, transformation, and distribution of iodine from soil to plants are poorly understood in amended soil. Thus, identifying an effective management option to enhance iodine (I) bioavailability in nutrient-deficient soils is currently a significant challenge. Therefore, a greenhouse study was conducted to investigate the effects of organic and inorganic soil amendments on the uptake of different iodine sources in coriander crops. Results showed that applying an inorganic iodine source significantly enhanced the iodine edible part of the crop compared to the control (p &amp;lt; 0.05). The application of soil amendments relatively improved iodine uptake by the coriander crop compared to the control. The highest iodine was found in crop tissues grown in wood ash-amended soil supplemented with KI (291.97 μg kg−1). The KI uptake was significantly higher than the OI (p &amp;lt; 0.05). Compared to OI, a higher translocation factor (0.96) and distribution coefficient (3.51) were found for plants treated with KI. Thus, this study indicates that a suitable soil amendment can be a better option for iodine biofortification and that it can serve as an alternative to iodized salt in preventing IDDs.

Residual effect of biofortified iodine in soil, plant, crop yield and quality of tomato (Solanum lycopersicum L.)

When iodine levels in the soil are inadequate, resulting in limited crop uptake and as a result, a population with insufficient iodine intake. Iodine deficiency can be avoided by biofortifying commonly consumed crops with iodine. Tomato is the best crop for biofortification study as it is having the capacity to store excess iodine in pholoem. The field experiment was carried out in Thondamuthur block of Viraliyur village at Coimbatore district of Tamil Nadu in 2021. The purpose of this study was to determine the effect of biofortication of iodine in residual tomato growth, yield, quality and iodine content. Potassium iodate and Chitosan were applied in the form of soil, foliar and Chitosan iodate complex at different stages of plant growth. The results revealed that the soil fertilization of potassium iodate alone resulted in lower uptake of residual iodine in fruits because the iodine was susceptible to high volatilization and less phyto-availability. While foliar spray alone increased the residual iodine content in roots and stem. However, residual higher iodine accumulation in the tomato fruits was achieved through the combination of foliar and iodine Chitosan forms. As electrostatic interaction between Chitosan and iodate prevents volatilization and gradually increases the bioavailability of iodine from soil to fruits. Based on the discussion, biofortification of iodine through potassium iodate Chitosan complex paved the way for the improvement of growth, yield, quality and iodine content in fruits. Hence, biofortification of iodine through iodate Chitosan complex increased the iodine content in tomato fruit and introducing it in our daily diet may be helpful to reduce iodine deficiency disorder.

Iodine Bioavailability and Accumulation of Arsenic and Cadmium in Rats Fed Sugar Kelp (Saccharina latissima).

Suboptimal iodine status is a prominent public health issue in several European coun-tries. Brown algae have a high iodine content that, upon intake, may exceed the recommended dietary intake level, but iodine bioavailability has been reported to be lower than from potassium iodide (KI) and highly depends on algae species. Further, potential negative effects from other components in algae, such as cadmium (Cd) and arsenic (As), have also been addressed. In this study, we observed a lower bioavailability of iodine from farmed sugar kelp (Saccharina latissima) than from KI in female Wistar IGS rats. Urinary iodine excretion was 94-95% in rats fed KI and 73-81% in rats fed sugar kelp, followed by increased faecal iodine levels in rats fed sugar kelp. No effects on body weight, feed efficiency, or plasma markers for liver or kidney damage were detected. The highest dose of iodine reduced plasma free thyroxine (fT4) and total T4 levels, but no significant effects on circulating levels of thyroid-stimulating hormone (TSH) and free triiodo-thyronine (fT3) were detected. Faeces and urine measurements indicate that 60-80% of total As and 93% of Cd ingested were excreted in rats fed 0.5 and 5% kelp. Liver metabolomic profiling demonstrates that a high inclusion of sugar kelp in the diet for 13 weeks of feeding modulates metabolites with potential antioxidant activity and phytosterols.

Iodine level and Hardness in Drinking Water in Selected Areas of Howrah and Purba Medinipur District, West Bengal state of India

Endemic goiter has been reported from the southern part of West Bengal. The bioavailability of iodine and hardness of water used for drinking in the region are inversely and directly related to goiter prevalence in several geographical regions. These factors were evaluated to study the etiological factors for the persistence of endemic goiter. The local drinking water concentration can give an induction of the iodine content of the soil. Water hardness is defined by the high concentrations of calcium and magnesium present. In the present study, 5 Community Development (CD) Blocks and 8 CD Blocks attached to the river Ganga are selected from Howrah and coastal areas of Purba Medinipur district, respectively. From each CD Block, at least 8 drinking water samples were collected and analyzed for iodine, calcium, and magnesium content. Iodine content in drinking water samples was found in the range from 7.5 to 95.4 μg/L and the hardness of drinking water was found to range from 210.3 to 625.7 ppm. The presence of magnesium was found to be higher than the calcium salts in most of the samples. These findings suggest that all most all the studied region is environmentally iodine sufficient but water is relatively hard and thus, the possibility of the hardness of water for the persistence of endemic goiter may not be ruled out.

Influence of potassium iodate and chitosan iodate complex on growth, yield, quality and iodine uptake in ‘shivam’ hybrid of tomato (Solanum lycopersicum L.)

An iodine biofortification experiment was conducted by applying potassium iodate fertilizer in soil and foliar form and chitosan complex forms to investigate the growth, yield, quality and uptake of iodine in shivam hybrid of tomato in Palaviduthi soil series of Coimbatore region. Soil fertilization alone resulted in lower uptake of iodine in fruits because the iodine is susceptible to high volatilization and less phytoavailability and also resulted in less yield and poor quality of fruits. When the chitosan and potassium iodate were applied in combination through foliar form, the quality of the fruits was found to be superior (carotene-1.24 mg 100gm-1 ascorbic acid- 3.56 mg 100gm-1, titrable acidity-0.96%), with higher fruit yield (94.81 t ha-1) and uptake of iodine in fruits (0.99ppm). Potassium iodate alone, either in the form of soil or foliar application, increased the quality of fruits, but it did not prevent the loss of various pigments and acids during ripening and also the loss of iodine through volatilization. But chitosan conserved the losses by reducing the respiration rate and oxygen permeability. Further, chitosan formed an electrostatic interaction with potassium iodate, preventing volatilisation and gradually increasing the bioavailability of iodine from soil to fruits. Hence biofortifying iodine in the form of potassium iodate chitosan complex was preferred for enhancing yield, improving quality and increasing the iodine content in fruits.

Iodine from brown algae in human nutrition, with an emphasis on bioaccessibility, bioavailability, chemistry, and effects of processing: A systematic review.

Brown algae are becoming increasingly popular as a food source and dietary supplement in Europe and other Western countries. As they are highly rich in iodine, they represent a potential new dietary iodine source. Iodine deficiency has been re-emerging in Europe, and it is important to ensure adequate intake through one's diet. However, macroalgae, and especially brown algae, may contain very high amounts of iodine, and both iodine deficiency and excessive iodine may increase the risk of negative health effects. The iodine content of algae or foods containing algae is currently not regulated in the European Union. The aim of this paper is to review the literature to determine the chemical species of iodine in brown algae, the loss of iodine during processing, and the bioavailability and bioaccessibility of iodine. A systematic search of the literature was performed in April 2021, via the databases Web of Science and PubMed. The review includes studies of iodine in brown macroalgae in relation to bioavailability, bioaccessibility, processing and speciation. A meta-analysis was conducted in relation to the following topics: (i) the correlation between total iodine and iodide (I- ) content in brown algae; (ii) the correlation between the loss of iodine during processing and the I- content; and (iii) the correlation between bioavailability and the I- content. The bioavailability of iodine from brown algae was generally high, with in vivo bioavailability ranging from 31% to 90%. The in vitro bioavailability of iodine (2%-28%) was systematically lower than in vivo bioavailability (31%-90%), indicating an inadequate in vitro methodology. Processing may reduce the iodine content of brown algae, and a higher I- content was positively correlated with increased iodine loss during processing. Although processing strategies may reduce the iodine content of brown algae significantly, the iodine content may still be high after processing. These findings may be used in food safety evaluations of brown algae as well as in the development of macroalgae-containing foods with iodine contents suitable for human consumption. Further research on processing techniques to reduce the iodine content in brown macroalgae are warranted.

Effects of Different Pretreatment Methods and Dietary Factors on the Form and Bioavailability of Iodine in Laminaria japonica

ABSTRACT The present study was aimed to evaluate the effects of different pretreatment methods (soaking, boiling, steaming) and dietary factors (ascorbic acid, citric acid, oxalic acid, phytic acid, tyrosine) on the bioavailability of iodine from Laminaria japonica by using In vitro simulated gastrointestinal digestion combined with Caco-2 cell model. The results showed that steamed L. japonica had the highest retention of iodine content (83.30 ± 3.91%), while boiling led to the largest iodine loss (38.46 ± 1.96%). Moreover, boiled L. japonica exhibited the greatest bioavailability (47.12 ± 5.28%) followed by steamed L. japonica (43.60 ± 3.05%). The presence of ascorbic acid, citric acid, or tyrosine promoted the cellular iodine absorption, while oxalic acid and phytic acid produced inhibitory effects. These findings suggested that the pretreatment methods and dietary factors could influence the actual intake of L. japonica sourced proteins and iodine by regulating their digestion characteristics and bioavailability.

THE EFFECT OF THE ADDITION OF ALGAE TO RYE BREAD ON THE CONTENT AND IN VITRO AVAILABILITY OF SELECTED MICRO- AND MACROELEMENTS

Background. Efficient methods of cultivating microalgae have been developed for the fuel industry in photobioreactors or open recirculation tanks. Reduced world fuel demand makes the production of thirdgeneration biofuels less profitable. Algae producers are looking for alternative applications for them and have high hopes for the food industry. Algae biomass is an excellent source of food ingredients – it is rich in easily digestible and well-balanced protein and is characterized by a high content of macro- and microelements occurring in easily digestible forms as complex or organometallic compounds. The presented study shows the results of an experiment aimed at examining the effect of adding microalgae in various forms (Arthrospira platensis and Ascophyllum nodosum - dried, granulated and smoked) to rye bread on the nitrogen, phosphorus, iron and iodine content. In order to test the bioavailability of these elements, the produced bread was subjected to a simulated in vitro digestion process. The dialysates and mineralized bread samples obtained were used to analyze the content of the above-mentioned macro- and microelements using spectrophotometric methods. Results and conclusion. The results obtained indicate a statistically significant effect of the addition of algae on an increase in the level of the elements discussed. The largest differences in the content of the analyzed macro- and microelements compared to the bread without additives were observed for the samples containing dried spirulina (Arthospira platensis) and Ascophyllum nodosum in the form of granules. The microalgae introduced into the rye bread also increased the bioavailability of iron and iodine.

Iodine Biofortificationin Tomato with a Strategy to Prevent Iodine Deficiency

A field experiment was conducted to investigate the potential of iodine biofortification in tomato fruits by fertilizing potassium iodate in soil, foliar form and chitosan complex forms. While foliar spray alone increases iodine content in leaves (95%), chitosan iodate complex alone and soil application alone increased iodine contentin roots (11% and 16%) and stems (19% and 27%). However, higher iodine accumulation (3%) in tomato fruits was achieved through the combination of foliar and iodine chitosan forms, as electrostatic interaction between chitosan and iodate prevents volatilization and gradually increases the bioavailability of iodine from soil to fruits. The transfer factor was higher for iodate and chitosan complex from soil to plant. Further, the average and relative distribution of iodine in plants revealed that the chitosan iodate complex and foliar spray combination is proven to be the most effective, as it keeps adequate amounts of iodine in roots, stems, and leaves while also increasing iodine content in final fruit. Biofortifying iodine through iodate chitosan complex increases iodine content in tomato fruit and introducing it in our daily diet may help to reduce iodine deficiency.

Evaluation of protein digestibility and iodine bioavailability in raw and cooked Sargassum fusiforme (harvey) setchell using in vitro methods

PurposeSargassum fusiforme is a popular edible seaweed in coastal cities of China that contains diverse nutrients including iodine. Cooking is an effective way to improve food safety, but it can alter both the contents of elements along with speciation and bioavailability. Three common cooking methods, the soaking, steaming and boiling, were evaluated for their effects on the protein structures, protein digestibility, iodine content and iodine bioavailability of S. fusiforme.Design/methodology/approachFourier transform infrared spectroscopy was used to study the structural changes of protein, and an in vitro digestion/Caco-2 cell culture system was used to evaluate the digestibility of protein, bioaccessibility and bioavailability of iodine.FindingsBoiling and steaming altered the protein secondary structure demonstrated by increased a-helix and random coil and decreased β-sheet, which improved the in vitro protein digestibility. Iodine content was reduced by cooking, with the highest loss observed after boiling, followed by soaking and steaming, while it was found that both bioaccessibility and cellular uptake of iodine were significantly elevated by boiling and steaming using an in vitro digestion/Caco-2 cell culture system. The presence of ascorbic acid, citric acid or tyrosine was beneficial for the iodine absorption, while oxalic acid and phytic acid hindered the iodine bioavailability.Originality/valueThe present finding suggested that cooking was conducive to the digestion and absorption of iodine in S. fusiforme. In addition, different dietary factors could have a certain impact on the absorption of iodine. Results of the study are essential for improving the application value of S. fusiforme to ensure reasonable consumption of seaweeds.

Extractability of iodine from soils using different methods in relation to soil properties

Variations in the iodine distribution in soil may occur due to the different soil parameters. There is a general consensus that the extractability of iodine from soils can provide useful information on the bioavailability of iodine. The purpose of this study was to compare the results of three methods namely Kesari et al. (Chem Anal 43:201-207, Kesari et al. 1998) (KM), Sandell and Kolthoff (J Am Chem Soc 56(6):1426-1426, Sandell and Kolthoff 1934) (SK), and titration method (DeMaeyer et al. 1979) (TM) for the iodine determination in soils, under different types of use and management. Soil properties were correlated with the availability of iodine. Results showed that iodine contents were higher in the forest and pasture soils compared to the barren soil. A superior recovery of iodine was achieved by KM and this also showed a greater relationship of iodine contents with soil properties. The extractability of iodine contents was positively associated with cation exchange capacity (CEC) and organic carbon (OC) and negatively related to soil pH. The relationship of iodine with soil properties predicted the substantial effects of land uses on the extractability of iodine contents from soils. It was confirmed that iodine variations in soils were largely dependent upon soil properties as well as extraction methods.