Selenium in Gluten-free Products

Enhanced determination of iodine by molecular absorption spectrometry after dispersive solid-phase extraction with direct quantification of selenium in foods

The determination of iodine after the enrichment on solid sorbent ZrO2 in the combination with molecular absorption spectrometric (MAS) detection is presented. The detection limit and enrichment factor obtained were 0.009 μg mL-1 and 9, respectively. The main extraction parameters were: sample pH = 3, 40 mg of ZrO2 and 300 μL of eluent (4 % C6H8O6). The correctness was evaluated by analyzing the matrix-compatible standard reference materials (SRMs). The iodine and selenium contents measured in these reference materials were in satisfactory agreement with the certified values according to the t-test for a 95 % confidence level. The method was used to determine iodine in food samples. To discuss the impact of iodine on human health, the selenium content was also determined. The results obtained can provide consumers with information on the iodine and selenium content of food, and thus help them to better control the functioning of important organs such as the thyroid.

Selenium in plant-based beverages: Total content, estimated bioaccessibility and contribution to daily intake

BACKGROUND

The search for alternative protein sources has increased the consumption and commercialization of plant-based beverages (PBBs). This study aimed to determine the total Se content, estimate the bioaccessibility of selenium (Se) in commercial PBBs derived from different raw materials, and evaluate their contribution to the reference daily intake (RDI).

METHODS

An ultrasound assisted acid digestion method and ICP-MS was used to determine Se, and the INFOGEST method to estimate the bioaccessible percentages. Validation of this method was also performed, and the parameters obtained were: LOD and LOQ were 2.1 and 4.0 µg/kg, respectively. For accuracy, recovery percentages ranged from 99 % and 111 % (certified reference materials), and 95 % and 101 % (spiked experiments for bioaccessible extracts as recoveries).

RESULTS

The PBBs presented total Se content between 4 and 226 µg/kg. Bioaccessible percentages ranged from 63.5 % (mix of plant sources) to 95.9 % (produced with organic cashew nuts). Only one cashew nut PBBs supplied the daily demand of Se, representing 64.6 %, 75.3 % and 82.2 % of the RDI; for lactating and pregnant women, children (≥ 4 years) and adults, respectively.

CONCLUSIONS

The Se determination method through acid digestion assisted by ultrasound and ICP-MS was considered adequate for the PBBs samples. Se content varied according to the raw material used in sample preparation. High percentages (> 60 %) of bioaccessibility were observed and only one PBBs derived from organic cashew nuts supplied the recommended Se demand for different groups of individuals.

Association of selenium levels with the prevention and control of Keshan disease: A cross-sectional study

PURPOSE

The prevalence of Keshan disease (KD) is low and has reached controlled or eliminated levels even in counties that had a high KD prevalence in the past. Few nationwide surveys on selenium levels in KD areas have been conducted in the past 2 decades. We conducted a cross-sectional study to investigate the selenium levels and their association with KD control and prevention in areas where KD is prevalent.

METHODS

We collected 2143 human-hair, 698 soil, 701 rice, 607 flour, 521 corn, and 330 other-food samples from 49 counties with KD and 19 non-KD counties of nine KD provinces of China. The selenium content of samples was examined with hydride generation atomic fluorescence spectrometry. The difference in selenium levels between the KD and non-KD areas was analyzed. Cochran-Armitage trend tests were used to evaluate the association between selenium levels and KD control.

RESULTS

The selenium levels in human hair, soil, staple foods, and other foods in the KD areas (0.2996 mg/kg, 0.1380 mg/kg, 0.0190 mg/kg and 0.0076 mg/kg, respectively) were lower than those in the non-KD areas (0.3700 mg/kg, 0.1930 mg/kg, 0.0240 mg/kg and 0.0165 mg/kg, respectively). The Cochran-Armitage tests showed that there was a trend for the selenium standard ratio in the counties to increase in the order of KD uncontrolled, to controlled, to eliminated (Z = 2.229, P < 0.05).

CONCLUSION

The residents in the KD areas were found to be selenium-deficient. Improving the supply of staple foods containing selenium levels exceeding 0.025 mg/kg and abundant foodstuffs might contribute to KD control and prevention.

Effects of selenium on macro- and micro nutrients and selected qualitative parameters of oat (Avena sativa L.)

The article deals with the effect of foliar Se application on macro-and micro-elements and selected quantitative parameters (the content of ash, starch, and fat) in oat grains. The three-year experiments were carried out on Research and Breeding Station Vígľaš – Pstruša in the years 2014, 2015, 2016. The used oat variety was Valentin. The experiment was performed by a block method within a parcel size of 10 square meters (8 x 1.25 m) with the span of rows amounting to 0.125 m in four replications. Alfalfa was grown as forecrop. A potato and wheat production area (III-C2) with a height of 375 m above the sea level. The experimental area is characterized by warm, slightly wet weather with an average annual temperature of 7.8 °C and average annual precipitations of 666 mm. Basic fertilizing was planned before the sowing in the form of 100 kg of Ammonium nitrate containing dolomite (27% N), 100 kg of 60% KCl (60% of K2O), and100 kg of MAP (Monoammonium phosphate 12% N and 52% P2O5). Selenium was foliar applied in doses 25 g and 50 g Se per hectare in a solution form of sodium selenate (Na2SeO4). The harvest was realized by a small plot harvester in BBCH 91. The results of the experiments showed a statistically non-significant effect on microelements and most macroelements. Only sulfur content in oat grains was statistically significantly influenced by Se foliar treatment. The contents of ash, starch, and fat in oat grains were monitored, which showed statistically significant effect only in fat. Se content in grains showed a statistically significant increase by both Se foliar treatments.

Tuning of the Amount of Se in Rice (Oryza sativa) Grain by Varying the Nature of the Irrigation Method: Development of an ICP-MS Analytical Protocol, Validation and Application to 26 Different Rice Genotypes

The amount of specific trace elements like selenium (Se) may be of health concern for humans if contained in too high (or low) quantities in staple foods like rice. Among the attempts aimed to optimize the Se concentration in rice, only few studies have been focused on the use of irrigation methods other than continuous flooding. Since intermittent irriguous methods, like sprinkler and saturation, have found to be effective in modifying the bioaccumulation of arsenic and cadmium in rice kernels, the main goal of this study is to measure the amount of the total Se contained in grains of 26 rice genotypes cultivated for two consecutive agrarian vintages in the same open field and with the same water, but differently irrigated with continuous flooding, sprinkler or saturation. To do this, an original and validated ICP-MS method has been developed. The validation parameters accounted for a high sensitivity and accuracy. Sprinkler irrigation is able to reduce in the average of 90% the amount of total Se in kernels in comparison to values measured in rice irrigated with continuous flooding. In conclusion, different irrigation techniques and rice genotypes seem to be valuable tools in order to allow in the future the customized modulation of the Se concentration in rice grain according to the needs of the various populations.

Evaluation of Qualitative Dietary Protocol (Diet4Hashi) Application in Dietary Counseling in Hashimoto Thyroiditis: Study Protocol of a Randomized Controlled Trial

The current state of knowledge related to diet in Hashimoto thyroiditis (HT) is far from satisfactory, as many HT subjects experience several disorders and report reduced quality of life. There are three aims of the study: (1) to develop a qualitative dietary protocol (QDP; 'Diet4Hashi') as a simple, graphic-text tool dedicated to TH subjects, (2) to evaluate the use of the QDP in dietetic counseling compared to conventional dietetic counseling (CDC) in HT women, and (3) to assess the impact of both the QDP and the CDC on the diet quality, quality of life, adiposity, and metabolic parameters of HT women. The QDP is based on subject self-monitoring supported with a graphic-text tool to help them in food selection and adequate food frequency consumption, while the CDC on oral explanation and printed sample menus were provided by a dietician. The QDP contains two lists: (A) foods recommended for consumption and (B) foods with limited consumption, along with indicated consumption frequency per day/week/month. Both approaches include the same dietary recommendations for HT extracted from the literature but differ in subject-dietician cooperation. To summarize the evidence regarding dietary recommendations in HT, the PubMed, Embase, and Cochrane Library databases (to March 2019) and the bibliographies of key articles were searched. The study is designed as a dietary intervention lasting six months in two parallel groups: experimental and control. In the experimental group, the QDP will be applied, while in the control group, the CDC will be applied. In total, the study will include a baseline of 100 women with diagnosed HT. The subjects will be randomly allocated into the experimental/control groups (50/50). Data related to diet quality and other lifestyle factors, nutrition knowledge, quality of life, thyroid function, body composition, blood pressure, serum fasting glucose, and lipid profile at baseline and after a six-month follow-up will be collected. This study was conducted to develop a dietary protocol (Diet4Hashi) that is easy to follow for HT subjects, and it will contribute to providing valuable data that are useful to dieticians and physicians. It is anticipated that this graphic-text qualitative dietary protocol, by improving food selection and diet quality, may reduce adiposity and improve metabolic parameters and the quality of life of HT women.

Selenium and Autoimmune Diseases: A Review Article

BACKGROUND

Selenium is an essential trace element with fundamental effects on human biology. Trace elements deficiency is not an uncommon finding in autoimmune diseases. This deficiency may be a consequence of autoimmune diseases or may contribute to their etiology. With regard to evidence showing the association between selenium deficiency and generation of reactive oxygen species and subsequent inflammation, reviewing the role of selenium in collagen vascular diseases could help researchers to devise strategies for managing these diseases.

OBJECTIVE

The present study aimed to evaluate the role of selenium and autoimmune rheumatic diseases.

DATA SOURCES

PubMed, Scopus, Science Direct, and Google Scholar.

STUDY ELIGIBILITY CRITERIA

All the studies on the use of selenium without any limitations in terms of the preparation method, administration route, or formulation process were included in the study. The exclusion criteria were: 1) Articles published in languages other than English, 2) Administration of chemical and hormonal drugs rather than selenium, 3) Investigation of the effects of selenium on the autoimmune problems in animal models, and 4) Insufficiency of the presented data or poor description of the applied methods. Furthermore, review articles, meta-analyses, expert opinions, editorial letters, case reports, consensus statements, and qualitative studies were excluded from the study.

DATA EXTRACTION

In this systematic review, articles were evaluated through searching following keywords in combination with selenium: "autoimmune rheumatic diseases "or "scleroderma" or "systemic sclerosis" or "Behcet's disease" or "Sjögren syndrome" or "systemic lupus erythematosus" or "musculoskeletal diseases" or "rheumatoid arthritis" or "vasculitis" or "seronegative arthritis" or "antiphospholipid antibody syndrome".

RESULTS

Of 312 articles, 280 were excluded and 32 articles were entered in this study. Based on the majority of studies assessing selenium level in patients with collagen vascular diseases, lower selenium levels were observed in these patients. Moreover, the majority of articles showed an improvement in clinical symptoms of collagen vascular diseases compared to controls after the treatment of patients with different dosages of L-selenomethionine.

CONCLUSION

A decrease in the serum level of selenium was noted in patients with autoimmune diseases, which may be a risk factor for inflammation and initiation of autoimmunity in these patients. A sufficient quantity of selenium has been shown to contribute to the management of complications of autoimmune diseases and even improved survival in patients with autoimmune diseases, which may be due to the anti-inflammatory effects of selenium. Since this issue is of clinical importance, it can be considered in potential nutrition interventions and have beneficial effects on some autoimmune diseases.

Chemometric analysis of minerals in gluten-free products

BACKGROUND

Numerous studies indicate mineral deficiencies in people on a gluten-free (GF) diet. These deficiencies may indicate that GF products are a less valuable source of minerals than gluten-containing products. In the study, the nutritional quality of 50 GF products is discussed taking into account the nutritional requirements for minerals expressed as percentage of recommended daily allowance (%RDA) or percentage of adequate intake (%AI) for a model celiac patient. Elements analyzed were calcium, potassium, magnesium, sodium, copper, iron, manganese, and zinc. Analysis of %RDA or %AI was performed using principal component analysis (PCA) and hierarchical cluster analysis (HCA).

RESULTS

Using PCA, the differentiation between products based on rice, corn, potato, GF wheat starch and based on buckwheat, chickpea, millet, oats, amaranth, teff, quinoa, chestnut, and acorn was possible. In the HCA, four clusters were created. The main criterion determining the adherence of the sample to the cluster was the content of all minerals included to HCA (K, Mg, Cu, Fe, Mn); however, only the Mn content differentiated four formed groups.

CONCLUSION

GF products made of buckwheat, chickpea, millet, oats, amaranth, teff, quinoa, chestnut, and acorn are better source of minerals than based on other GF raw materials, what was confirmed by PCA and HCA. © 2017 Society of Chemical Industry.

Selenium deficiency in subtropical littoral pampas: environmental and dietary aspects

Se deficiency has a critical effect on human health. The littoral near Patos Lagoon in the south of Brazil is composed of Quaternary sandy deposits and nutrient-deficient soils, which contribute to Se deficiency in the surrounding environment. The average concentration of Se in littoral soils is six times lower than the metalloid deficiency threshold of 0.5 mg kg^-1 and is close to that in countries where Keshan disease is registered. The sediments in the Patos Estuary are also notably lower in Se than near-shore marine sediments. Foodstuffs produced in the littoral pampas are characterised by extremely low Se concentrations compared with the same alimentary products reported worldwide. The total daily dietary intake of Se in the region is 24 μg day^-1, which is half the Estimated Average Requirement for adults. Black beans in the local diet provide over 40% of daily Se intake. Prescriptive addition of Se to prevalent products seems the most effective solution to the problem of metalloid dietary deficiency in the region. Similar environmental conditions and significant concentration of the population in the littoral zone suggest that the problem of Se deficiency probably affects a large proportion of the population along the Atlantic coast of Brazil.

Tef: The Rising Ancient Cereal: What do we know about its Nutritional and Health Benefits?

This review covers the nutritional significance of tef cereal as compared to other common cereals with emphasis on carbohydrate content and starch digestibility, protein content, iron and zinc bioavailability and antioxidant potentials. Tef is a gluten free cereal and contains the highest iron and calcium among other cereals. It has high micro- and macro- nutritional profile and is becoming globally popular in the healthy grain food chain. Tef starch has a high gelatinization temperature, an essential precondition in the preparation of low glycemic index foods. There are significantly conflicting reports of iron content of tef ranging from 5 to 150 mg/100 g dm. The traditional fermentation of injera reduced majority of the phytic acid but no significant change to mineral bioavailability was observed. This review indicated that studies on starch digestibility, protein characterization, amylase and protease inhibitors, mineral bioavailability and antioxidant potentials are needed to further explore the nutritional and health benefits of tef.

Chemical composition and food uses of teff (Eragrostis tef)

Teff (Eragrostis tef) is a cereal native to Ethiopia and Eritrea. It has an excellent adaptability to harsh environmental conditions and plays an important role in food security. In recent years, teff is becoming globally popular due to the attractive nutritional profile such as gluten free and high dietary fiber content. This review documents the recent advances in the genetic diversity, nutritional composition and food uses of teff grain. The attractive nutrients of teff include protein, dietary fiber, polyphenols, and certain minerals. Whole grain teff flour becomes increasingly important in healthy food market, and has been used to produce various gluten free food items such as pasta and bread. Efforts have been made to enhance the sensory quality of teff based products. There is great potential to adapt teff to the other parts of the world for healthy food and beverage production.

Cultivation of Agaricus bisporus enriched with selenium, zinc and copper

BACKGROUND

Agaricus bisporus (white button mushroom) is an important culinary and medicinal species of worldwide importance. The present study investigated for the first time whether it may be grown on substrates supplemented with Se alone or in combination with Cu and/or Zn (0.1-0.8 mmol L^-1 ) to produce fruiting bodies of increased nutritional value.

RESULTS

As found, substrate supplementation did not affect yielded biomass up to 0.6 mmol L^-1 element concentrations regardless of the cultivation model. At 0.8 mmol L^-1 Se + Cu and Se + Zn supplementation biomass comparable with controls still developed. The accumulation of trace elements in the fruiting bodies generally increased over the concentration gradient reaching its maximum at 0.6 mmol L^-1 (for Se + Zn and Se + Cu + Zn) and 0.8 mmol L^-1 (for Se and Se + Cu). The organic Se constituted the greatest share in total Se quota. As calculated, each 10 g of dried fruiting bodies of A. bisporus obtained from 0.6 or 0.8 mmol L^-1 supplementation would represent 342-469% of the Recommended Daily Allowance (RDA) for Se, 43.4-48.5% for Cu and 5.2-5.8% for Zn.

CONCLUSION

Considering inexpensive methods of A. bisporus cultivation, global popularity and use of this mushroom, its biofortification with Se, Cu and Zn could have a practical application in deficiency prevention and assisted treatment. © 2016 Society of Chemical Industry.