Selenium content, chemical composition and volatile components of essential oil and hydrosol from flowers of Cardamine violifolia.

Cardamine violifolia is a unique selenium hyperaccumulating vegetable in China, but its flowers are commonly wasted in large-scale cultivation. To better utilize this resource, this study explored the selenium content, chemical composition, and volatile organic compounds (VOCs) of hydro-distilling essential oil (EO) and hydrosol from C. violifolia flowers. ICP-MS results indicated that the EO and hydrosol contained selenium reaching 13.66±2.82 mg/kg and 0.0084±0.0013 mg/kg, respectively. GC-MS analysis revealed that organic acids, hydrocarbons, and amines were the main components of EO. Additionally, benzyl nitrile, benzaldehyde, benzyl isothiocyanate, benzyl alcohol, megastigmatrienone, and 2-methoxy-4-vinylphenol also existed in considerable amounts. The hydrosol extract had fewer components, mainly amines. HS-SPME-GC-MS corresponded to the composition analysis and aromatic compounds were the prevalent VOCs, while HS-GC-IMS primarily identified C2-C10 molecular alcohols, aldehydes, ethers, and sulfur-containing compounds. This study first described the chemical composition and VOC profiles of EO and hydrosol from selenium hyperaccumulating plant.

First review on the selenium status in Germany covering the last 50 years and on the selenium content of selected food items.

INTRODUCTION: Selenium is important for human health. However, the selenium status and selenium intake of the German population has not been recorded in a representative study so far. MATERIAL AND METHODS: Thus, literature from the last 50 years was screened in a systematic way and the results of various studies were pulled together to shed light on the selenium status of the German population. Moreover, the selenium content of selected food items that were either found on the German market or grown in Germany was researched and evaluated. RESULTS: Of 3542 articles identified, 37 studies met the inclusion criteria. These 37 studies comprised a total of 8,010 healthy adults living in Germany with a weighted arithmetic mean of 82 µg/l selenium in plasma or serum. The results will form a basis for interpreting upcoming results from national food consumption surveys. Furthermore, 363 selenium values for 199 food items were identified out of 20 data sources-published or analysed between 2002 and 2019. An estimation of the selenium intake of the German population will be possible with this data in future nutrition surveys.

Effects of selenium application concentration, period and method on the selenium content and grain yield of Tartary buckwheat of different varieties.

BACKGROUND: As a potential selenium-enriched crop, it is of great significance to study the selenium application of Tartary buckwheat. Therefore, to study the effects of selenium application concentration, variety, selenium application period and method on the grain selenium content and yield of Tartary buckwheat, an orthogonal experimental design was used to carry out field experiments in the Jinzhong and Northwest Shanxi ecological regions at the same time. Heifeng 1 and Jinqiao 2 were applied at the branching stage and flowering stage in the Jinzhong, and Heifeng 1 and Jinqiao 6 were applied at the early flowering stage and peak flowering stage in the Northwest Shanxi with different concentrations of sodium selenite (0, 1.37, 2.74, 5.48, 8.22, 12.33, 18.495, 27.7425 g hm-2 ) by foliar spraying and soil application. RESULTS: The results showed that the selenium content in Tartary buckwheat grains was positively correlated with the selenium application concentration and increased with increasing selenium application concentration, while the yield of Tartary buckwheat first increased and then decreased with the selenium application concentration. The grain selenium content and yield of Tartary buckwheat were affected by the selenium application concentration, variety and application method. CONCLUSION: The most effective selenium biofortification program was spraying 2.32 g hm-2 sodium selenite on the leaves of Heifeng 1 at the early flowering stage in the Jinzhong. In the Northwest Shanxi, spraying 11.01 g hm-2 sodium selenite on the leaves of Jinqiao 6 at the flowering stage was the most effective selenium biofortification program. © 2022 Society of Chemical Industry.

Distribution characteristics and main influencing factors of selenium in surface soil of natural selenium-rich area: a case study in Langao County, China.

In order to study the distribution of selenium in surface soil and its main influencing factor, we collected 360 surface soil samples and four groups of soil profiles with 210 corresponding parent rock samples in Langao County, Shaanxi Province (a typical high-selenium area of Daba Mountain). Samples were analyzed for trace elements by using ICP-MS, ICP-OES and HG-AFS. The results show the following. (1) selenium content in surface soils of Langao County varies greatly (0.03-16.96 mg/kg). The mean selenium content in surface soils of Langao County is 0.99 mg/kg, higher than the global (0.4 mg/kg) and China (0.29 mg/kg) soil average, and 3.4 times the mean of soil selenium in China. (2) Selenium content of bedrock in Langao County also varies greatly (0.01-56.22 mg/kg), with an average selenium content of 2.02 mg/kg, which is 40 times higher than the upper crust (0.05 mg/kg). (3) Selenium content in the strata of the Late Precambrian-Early Paleozoic and its variation is an important factor affecting the spatial variation of soil selenium content. The black rock series (carbonaceous slate and silicon-bearing carbonaceous slate) of the Upper Ediacaran-Cambrian on the north side has the highest mean selenium content (> 7.92 mg/kg), and the selenium content of the surface soil in the distribution area can reach up to 16.96 mg/kg. The Middle Cambrian, Upper Cambrian, Ordovician and Silurian (limestone and marl) in the south has the lowest mean selenium content (< 2 mg/kg), and the selenium content of surface soil in the distribution area is lower than 0.8 mg/kg mostly. (4) Soil samples at different depths in the same soil profile have similar composition of rare earth elements (REE), and bedrock and corresponding topsoil has similar composition of REE. This study indicates the selenium content in the topsoil varies greatly, even in high-selenium area. And the difference of selenium distribution is closely related to the original selenium content of the bedrock.

Selenium-Rich Black Soldier Fly Supplementation Enriches Serum Indexes and Egg Selenium Content in Laying Hens.

A certain amount of selenium (Se) is usually added to the diet of laying hens to improve the quality and nutritional value of eggs. The present study was carried out to investigate the effect of selenium-rich black soldier fly (BSF) supplementation in diets on laying production performance, egg quality, serum indexes, and egg selenium content of Hy-line variety brown laying hens. A total of 288 at 49-week-old healthy laying hens were divided into 3 treatment groups with 6 replicates per group and 16 hens per replicate using a single-factor completely randomized design. Treatments consisted of (1) control (basal diet without supplemental Se), (2) 0.30 mg/kg supplemental Se, (Se as sodium selenite, SS), and (3) 0.30 mg/kg supplemental Se (Se as selenium-rich black soldier fly, SE-BSF). Laying performance was not affected by dietary Se. There was no effect of selenium-rich BSF on egg quality (P > 0.05). The contents of malonaldehyde (MDA) were significantly reduced (P < 0.05). On the contrary, dietary Se supplementation increased the activity of superoxide dismutase (SOD, P < 0.05) and catalase (CAT, P < 0.05) and increased the concentration of reduced glutathione (P < 0.05). In addition, selenium-rich BSF supplementation significantly increased the Se content of eggs (P < 0.05). These results indicate that Se supplementation did not affect laying production performance and egg quality of laying hens, but the supplementation could improve antioxidant capacity and increased the Se content of eggs.

Selenium enhancement strategy under precise fertilization in foxtail millet rhizosphere.

Enhancing selenium content in millet is a crucial strategy to address malnutrition due to selenium deficiency. Jingu 21 was used as the experimental material in this study. The effects of selenium fertilizer application amount, vertical position of fertilization, and horizontal position of fertilization on the selenium content in various millet organs were assessed using a three-factor, five-level quadratic rotation combination design. The results indicate that selenium fertilizer application amount, vertical fertilization position, and horizontal fertilization position significantly affected the selenium content in various millet organs. Analysis of the selenium accumulation for different millet organs show that the recommended optimal agronomic strategy for producing selenium-enriched millet comprises a selenium fertilizer application amount ranging from 100.65 to 120.15 kg/hm2, a vertical fertilization position of 10.28-11.76 cm, and a horizontal fertilization position of 6.74-7.29 cm. This study elucidates the patterns of selenium content accumulation under precise fertilization measures of millet and provides valuable insights for implementing selenium enhancement techniques in the production of selenium-enriched millet.

Development and validation of a microwave-assisted digestion technique as a rapid sample preparation method for the estimation of selenium in pharmaceutical dosage forms by ICP-OES.

Selenium is a class 2B element according to the International Council for Harmonization Q3D guidelines. Selenium sulfide is an anti-infective agent with antifungal and antibacterial properties used to treat dandruff and seborrheic dermatitis. The literature survey revealed that most of the analytical techniques to estimate selenium were time-consuming and/or required high skill levels. The process involved identifying the isotopes, selecting the measurement approach, and optimizing a typical microwave-aided digesting procedure. Ammonium hydrogen difluoride, water, and concentrated nitric acid were added to the samples. The confirmed microwave digestion program was a two-step program where in the initial step, the samples were ramped at 200°C for 20 min and held for 5 min. Later, samples were cooled and neutralized by boric acid, then ramped for 20 min to a temperature of 180°C and held for 10 min. Selenium was estimated at 196.090 nm by inductively coupled plasma optical emission spectroscopy (ICP-OES). System suitability was run before initiating analysis to ensure that system performance was consistent. Analytical validation parameters, such as the specificity of the method, were demonstrated at 196.090 nm, linearity was proven from 10 ppm to 150 ppm of selenium concentration, the detection limit was 1.28 ppm, and the limit of quantification was 3.89 ppm. Robustness was confirmed for small changes to ICP-OES operating conditions. The precision of the method demonstrated by analyzing the percentage relative standard deviation for six injections was found to be less than 2.0%. Accuracy was confirmed from 10 ppm to 150 ppm, and all the samples were observed to be within the range of 95%-105%. A common microwave-assisted digestion technique was developed and validated as well. The precision, specificity, linearity, accuracy, and robustness of the method for estimating selenium in selenium sulfide drug substances and various pharmaceutical dosage forms were demonstrated. This newly developed microwave-assisted digestion technique has optimum sensitivity and is highly reproducible and time-saving than the existing methods This method can be applied to numerous matrices for a finished dosage of selenium sulfide formulations.

Effect of supplementation and withdrawal of selenium-enriched kale sprouts on productivity and egg selenium concentration of laying hens.

OBJECTIVE: The aim of this trial was to investigate the effect of supplementation and withdrawal of selenium-enriched kale sprouts (SeKS) on productivity and egg Se concentration of laying hens. Selenium from commercial Se-enriched yeast (SeY) was used as a comparative Se source. METHODS: One-hundred and eighty 61-week-old laying hens were randomly divided into 5 treatment groups with 4 replicates (9 hens each) in a 2×2+1 Augmented Factorial Experiment in a completely randomized design. The experimental diets were basal diet, basal diet supplemented with 0.2 and 0.4 mg Se/kg from SeKS and SeY, respectively. The 8-week feeding trial was divided into 2 periods, namely the Se supplemental period (week 1 to 4) and the Se withdrawal period (week 5 to 8). RESULTS: Productive performance, egg quality and egg Se concentration of laying hens were not affected by sources of Se (SeKS and SeY) during both, the Se supplemental and withdrawal periods. Egg production and egg Se concentration increased (p<0.05) with increasing levels of Se supplementation. The egg Se concentration increased and reached a peak 1 week after Se supplementation. However, concentration of Se in eggs of hens fed Se from both sources decreased rapidly from the second week of the Se withdrawal period to reach the same egg Se concentration of hens fed the basal diet by the fourth week of the Se withdrawal period. CONCLUSION: The efficacy of Se from SeKS on productivity and egg Se concentration in laying hens was comparable to commercial SeY. Thus, SeKS can provide an alternate organic Se source for production of Se-enriched eggs.

Effects of Basal Selenium Fertilizer Application on Agronomic Traits, Yield, Quality, and Se Content of Dryland Maize.

To explore the efficiency of selenium (Se) fertilizer application in dryland maize, we tested five Se fertilizer application treatments: 0 g ha-1 (Se0), 75 g ha-1 (Se1), 150 g ha-1 (Se2), 225 g ha-1 (Se3), and 300 g ha-1 (Se4). Compared with Se0, Se2 increased the leaf area, chlorophyll content, internode length, plant height, and ear height by 7.95%, 3.20%, 13.19%, 1.89%, and 7.98%, respectively. Se2 and Se3 significantly affected the stem internode diameter, cortex thickness, and cellulose content, which were positively correlated with lodging resistance. Compared with Se0, Se3 promoted the contents of soluble sugar, crude protein, crude fat, and starch in grains, which increased by 9.48%, 6.59%, 1.56%, and 4.82%, respectively. It implies that maize grain application of Se significantly improves their Se content. Se1 did not observably influence the growth of maize, and the promoting effect of Se4 on maize decreased. The lodging resistance of maize as analyzed by Pearson correlation analysis correlated with the application of Se fertilizer. It proved that higher yield, grain quality, grain Se content, and lodging resistance of stems were concerned with Se fertilizer application in the range of 150-225 g ha-1. The results provide useful information for Se fertilizer treatment in dryland maize.

Effects of Applying Different Doses of Selenite to Soil and Foliar at Different Growth Stage on Selenium Content and Yield of Different Oat Varieties.

(1) Background: With the increase in people's consumption of processed oat products, the production of selenium (Se)-enriched oat has become a possibility to supplement the human body with Se. Therefore, the effects of various factors on the Se-enriched ability and yield of different oat varieties were comprehensively studied. (2) Methods: cv."Pinyan 5" and cv."Bayou 18" were applied at the stem-elongation stage and heading stage in the Jinzhong (JZ), and cv."Bayou 1" and cv."Jinyan 18" were applied at the heading stage and flowering stage in the northwestern Shanxi (JXB) with different doses of Na2SeO3 (0, 5.48, 10.96, 21.92, 43.84, 65.76, 98.64, 0, 5.48, 10.96, 21.92, 43.84, 65.76, 98.64, 147.96 g hm-2) by soil application and foliar spraying. (3) Results: The grain Se content and yield of oat were affected by the variety, Se application dose, stage and method of Se supplementation. Additionally, the Se content in oat grain was positively correlated with the Se application dose while the yield of oat first increased and then decreased with the Se application dose. (4) Conclusions: In the JZ and JXB, 21.92 g hm-2 and 43.84 g hm-2 Se was sprayed on the leaves of cv."Bayou 18" and cv."Bayou 1" at the heading stage, respectively, was the most effective Se biofortification program.

Synthesis, characterization, and biological evaluation of novel selenium-containing chitosan derivatives.

Though great efforts have been made to develop selenium polysaccharides with unique properties using HNO3-Na2SeO3 methods, the Se content is still low due to the poor esterification efficiency of H2SeO3. Herein, selenodiacetic acid (SA) was introduced into chitosan (CS) to synthesize O-selenodiacetyl chitosan (OSAC) and chitosan-ammonium selenodiacetate (CASA) by covalent and non-covalent interaction, respectively. The obtained CS derivatives were characterized by UV-vis, FTIR, 1H NMR, XPS, TGA, and XRD spectra, and the OSAC and CASA showed high Se content up to 15,720 ± 475 and 26,363 ± 698 µg/g. The OSAC and CASA demonstrated increased antioxidant activities compared to the CS in DPPH and ABTS free radical scavenging assays. Moreover, they exhibited a potent anticancer effect on HepG2 cells with the IC50 values of 0.918 and 1.459 µg/mL. Taken together, this study provides a promising strategy for the design of novel selenium polysaccharides with high Se content and greater biological activity.

Investigation of selenium nutritional status and dietary pattern among children in Kashin-Beck disease endemic areas in Shaanxi Province, China using duplicate portion sampling method.

BACKGROUND AND OBJECTIVES: Selenium deficiency is a primary risk factor of Kashin-Beck disease (KBD). This study aimed to investigate whether children in endemic areas could maintain sufficient selenium intake after termination of selenium supplement administration, and evaluate their comprehensive nutritional status and dietary structure. METHODS: Duplicate portion sampling combined with a questionnaire was adopted to collect data on categories and quantity of all food ingested in three consecutive days. Occipital hair was also collected to detect selenium content by hydride generation atomic fluorescence spectrometry (HGAFS). CDGSS3.0 software and factor analysis were integrated to assess the children's comprehensive nutritional status and dietary structure. RESULTS: This study included 240 sex-matched (1:1) children aged 7-12 years from KBD endemic (n = 120) and non-endemic (n = 120) areas. Overall, 720 solid food, 720 liquid, and 240 hair samples were collected for selenium determination. The mean selenium level in hair of children in endemic areas (0.38 ± 0.16 mg/kg) was significantly lower than that in children in non-endemic areas (0.56 ± 0.28 mg/kg, Z = -5.249, p < 0.001). The dietary selenium intake of children in endemic areas was 40.0% lower than that in children in non-endemic areas (Z = -9.374, p < 0.001). Children in endemic areas consumed significantly less diverse dietary items leading to significantly less intake of multiple nutrients compared to children in non-endemic areas. CONCLUSIONS: The dietary selenium intake of most children in endemic areas was less than the recommended amount. The dietary structure of children was undiversified, which limited the intake of multiple nutrients. Therefore, comprehensive nutrition rather than sole selenium intake should be the primary concern in the future.

Selenium fertigation with nanobubbles influences soil selenium residual and plant performance by modulation of bacterial community.

Although selenium (Se) is an essential microelement for humans and animals, it is a potentially toxic element due to its bioaccumulation potential. In this study, Se fertilizer was supplied in a greenhouse vegetable (cucumber) plantation using an innovative system consisting of nanobubbles (NB_Se) and compared to that under conventional conditions of fertigation (C_Se) with six doses. The results revealed that NB_Se significantly reduced soil Se accumulation (38%-144%) and increased cucumber Se content compared with the C_Se treatments at the same Se dose. NB_Se significantly lowered the soil bacterial diversity, with an initial increase and then decrease with the Se doses. Bacterial associations and potential keystone taxa also differed between the NB_Se and C_Se. The greater abundance of oxidizing bacteria (indicated by the function composition of bacterial community) and the improved soil redox environment created by NBs sustained more available Se for plants, leading to a reduction in soil Se residual and an increase in the plant Se content. Our results highlight the feasibility and efficiency of NB_Se and demonstrate the important implications of Se for the maintenance of soil health and sustainability.

Effect of Different Cooking Methods on Selenium Content of Fish Commonly Consumed in Thailand.

Although fish are good sources of selenium (Se), an essential trace element for the human body, very limited data exist on Se content in commonly consumed fish in Thailand. Consequently, this study investigated selenium content and the effect of cooking among 10 fish species (5 freshwater and 5 marine) most-commonly consumed by the Thai people. The fish were purchased from three representative wholesale markets within or nearby to Bangkok. All fish species were prepared to determine their edible portions (EP) and moisture contents. Total Se in fresh, boiled, and fried fish were analysed using Inductively Coupled Plasma-Triple Quadrupole-Mass Spectrometry (ICP-QQQ-MS). In general, higher levels of Se were found in marine fish (37.1−198.5 µg/100 g EP in fresh fish, 48.0−154.4 µg/100 g EP in boiled fish, and 52.9−262.4 µg/100 g EP in fried fish) compared to freshwater fish (6.9−29.4 µg/100 g EP in fresh fish, 10.1−26.5 µg/100 g EP in boiled fish, and 13.7−43.8 µg/100 g EP in fried fish). While Longtail tuna showed significantly higher Se content than other fish (p < 0.05), boiled Longtail tuna had significantly lower true retention of Se than the other fish (p < 0.05). Most fish species retained a high level of selenium (ranged 64.1−100.0% true retention in boiling and frying). Longtail tuna, Short-bodied mackerel, Indo-pacific Spanish mackerel, Nile tilapia, and red Nile tilapia−cooked by boiling and frying−are recommended for consumption as excellent sources of selenium.

Determination of heavy metals and selenium content in chicken liver at Erbil city, Iraq.

Heavy metal contamination of poultry meat is a critical issue for human health due to associated risks of cytotoxicity and systemic pathologies after ingestion of such metals. A total of twenty chicken liver samples were collected from markets of Erbil city and analyzed for ten heavy metals contents by Inductively Coupled Plasma Optical Emission Spectrometry. The targeted metals were cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), mercury (Hg), zinc (Zn) and selenium (Se). The average concentrations (mg/kg) of targeted trace elements were 0.06±0.027, 0.06±0.05, 2.05±0.34, 1.85±0.47, 0.15±0.17, and 33.53±5.24 for Co, Cr, Cu, Mn, Ni, and Zn respectively. Copper (Cu) levels significantly exceeded the maximum permissible limit of WHO. Moreover, the average concentrations of toxic heavy metals and selenium were 0.07±0.037, 0.278±0.10, 0.11±0.083, and 2.01±0.454 mg/kg for Cd, Pb, Hg, and Se respectively. Hg and Pb levels exceeded the permissible limits of WHO. Higher levels of Cu and Hg in poultry may pose a serious threat to consumers which demand countermeasures and precautions to be taken. Iraqi Standards Authority and relevant official institutions are strongly recommended to regulate safe disposal of heavy metal waste in the environment to reduce animal exposure to such metals.

Effects of Selenium-Enriched Yeast on Performance, Egg Quality, Antioxidant Balance, and Egg Selenium Content in Laying Ducks.

This study investigated the effects of dietary selenium-enriched yeast (Se yeast) supplementation on the laying performance, egg quality, plasma antioxidant balance, and egg selenium (Se) content in laying Longyan ducks. A total of 480 32-week-old ducks were randomly divided into four dietary treatments, each consisting of six replicates of 20 ducks. The dietary treatments were a control basal diet and basal diets with supplementation of 0.05, 0.15, and 0.25 mg Se/kg via Se yeast. The analyzed Se contents of the four diets were 0.15, 0.21, 0.36, and 0.43 mg Se/kg, respectively. Dietary Se yeast supplementation had no apparent effects on laying performance and egg quality (p > 0.05), but it improved the antioxidant balance of ducks, as inferred by greater glutathione peroxidase and catalase activities, and decreased the malondialdehyde content in plasma of ducks (p < 0.05). It was suggested that the Se content in the basal diet containing 0.15 mg/kg of Se requirement is adequate for productive performance, but not for the antioxidant balance of laying ducks. Besides that, the Se contents in the yolk, albumen, and whole egg increased linearly as the Se supplementation levels increased. With more feeding days, the Se contents in the yolk and whole egg from non-Se-yeast-supplemented ducks increased linearly (p < 0.05), while those from Se-yeast-supplemented ducks showed a quadratic relationship (p < 0.05). In conclusion, the Se content of the basal diet at 0.15 mg/kg was adequate for laying performance and egg quality traits in laying ducks. Dietary Se yeast supplementation is beneficial to improve the antioxidant balance of laying ducks and increase the Se deposition in eggs for producing Se-enriched eggs. Based on the quadratic model or the quadratic broken-line model analyses, supplemental 0.19 mg Se/kg via Se yeast, with a total equivalent of 0.34 mg Se/kg in the diet, could provide the optimum antioxidant balance in laying ducks. Dietary supplementation of 0.25 mg Se/kg via Se yeast, with a total equivalent of 0.40 mg Se/kg in the diet, could lead to achieving the desired Se content in the whole egg.

Determination of Selenium in Common and Selenium-Rich Rice from Different Areas in China and Assessment of Their Dietary Intake.

In this study, 41 common rice varieties and 211 selenium-rich rice varieties from ten representative areas in China were collected in 2017-2019. The selenium contents of rice were analyzed with optimized inductively coupled plasma mass spectrometry (ICP-MS). Selenium concentrations of common rice and selenium-rich rice ranges were 0.81-7.26 and 0.76-180.73 µg/100 g, respectively. The selenium contents in selenium-rich rice from different areas were significantly different (p < 0.001) while those in common rice from different areas were not. The selenium-rich rice in Harbin and Keshan showed the lowest selenium level and those from selenium-rich areas (Enshi and Ankang) were highest. Based on the estimation of the risk assessment software @risk7.0 (Palisade Corporation, New York, NY, USA), the consumption of selenium-rich rice can effectively increase dietary selenium intake for the population. However, the risk index of P95 (Percentile 95) selenium exposure at the tolerable upper intake level for children at 2-14 years old exceeded 100%, with potential risk currently. Therefore, the consumption of selenium-rich rice should be properly monitored for young children and adolescents.

Effect of Selenium from Selenium-Enriched Kale Sprout Versus Other Selenium Sources on Productivity and Selenium Concentrations in Egg and Tissue of Laying Hens.

A 6-week trial was conducted to compare the effect of selenium (Se) from hydroponically produced Se-enriched kale sprout (HPSeKS), sodium selenite (SS), and Se-enriched yeast (SeY) in laying hens. A total of 144 40-week-old hens were randomly divided into four groups, according to a completely randomized design. Each group consisted of four replicates with nine hens per replicate. The dietary treatments were T1 (basal diet) and T2, T3, and T4 (basal diets supplemented with 0.30 mg Se/kg from SS, SeY, and HPSeKS, respectively). Results showed that Se supplement did not affect (p > 0.05) productivity and egg quality. Hens fed Se from HPSeKS and SeY exhibited higher (p < 0.05) Se bioavailability than hens fed Se from SS. Whole egg Se concentration of hens fed Se from HPSeKS was similar (p > 0.05) to that of hens fed Se from SeY, but higher (p < 0.05) than that of hens fed Se from SS. However, the breast muscle and heart tissue Se concentrations of hens fed Se from SS, SeY, and HPSeKS were not different (p > 0.05). The results of this trial demonstrated that Se from HPSeKS and SeY was more efficient than Se from SS on Se bioavailability and whole egg Se concentration in laying hens.

Selenium (Se) uptake and dynamic changes of Se content in soil-plant systems.

In this study, we collected crop plants and associated soil samples and determined these for selenium (Se) content to analyze the uptake, enrichment, and translocation of Se in the different soil-plant systems of an agricultural production area, elucidate the dynamic mechanisms relating to Se content in plants and soil during different growth periods, and screen plants for high Se enrichment ability. Bioconcentration factor determinations indicated that the grains of rice have the strongest Se enrichment ability, followed by soybean and corn. Translocation factor analysis indicated that the grains of rice and corn have similar low translocation abilities for Se compared with soybean. Within the study area, the Se content in plants was closely related to the soil available Se content and varied considerably among different growth periods and plant organs. This study provides a theoretical basis for the development and utilization of local agricultural products.

Is It the Appropriate Time to Stop Applying Selenium Enriched Salt in Kashin-Beck Disease Areas in China?

We aimed to identify significant factors of selenium (Se) nutrition of children in Kashin-Beck disease (KBD) endemic areas and non-KBD area in Shaanxi Province for providing evidence of whether it is the time to stop applying Se-enriched salt in KBD areas. A cross-sectional study contained 368 stratified randomly selected children aged 4-14 years was conducted with 24-h retrospective questionnaire based on a pre-investigation. Food and hair samples were collected and had Se contents determined with hydride generation atomic fluorescence spectrometry. Average hair Se content of 349.0 ± 60.2 ng/g in KBD-endemic counties was significantly lower than 374.1 ± 47.0 ng/g in non-KBD counties. It was significantly higher in the male children (365.2 ± 52.3 ng/g) than in the female (345.0 ± 62.2 ng/g, p = 0.002) and significantly higher in the 4.0-6.9 years group (375.2 ± 58.9 ng/g) than the 7.0-14.0 years group (347.0 ± 56.1 ng/g, p < 0.01). Gender, living area, Se intake without supplements, Se-enriched salt, oil source and protein intake were identified as significant factors of hair Se contents. Cereals, meat and milk were commonly included as significant food categories that mainly contributed to Se intake without supplement of the whole population. Balanced dietary structure without Se supplement could effectively enhance and maintain children's Se nutrition. It may be the time to stop applying Se-enriched salt in KBD areas in Shaanxi Province.