The silicon content of beer and its bioavailability in healthy volunteers

Dietary Si, as soluble orthosilicic acid (OSA), may be important for the growth and development of bone and connective tissue. Beer appears to be a major contributor to Si intake, although the Si content of beer and its bioavailability in human subjects have not been well established. Here we investigated the Si content of different beers and then estimated Si absorption from beer in healthy volunteers. The Si content of seventy-six different beers was estimated using inductively coupled plasma optical emission spectrometry and one of the beers, used in the ingestion study, was ultrafiltered to determine OSA content. Next, following the ingestion of 0·6 litres beer (22·5mg Si; 4·6% (v/v) ethanol), serum and urinary Si levels were measured in nine healthy volunteers over a 6h period. A solution of OSA was similarly investigated as a positive control and water and 4·6% ethanol as negative controls. The mean Si level of beer was 19·2 (SD 6·6) mg/l; the median Si level was 18·0mg/l. There was no significant difference in the Si levels of the different beers by geographical origin or type of beer. Serum and urinary Si levels increased considerably following the ingestion of beer or a solution of OSA but not with the ingestion of either 4·6% ethanol or water. The ultrafilterability of Si from beer (about 80%) and its absorption in volunteers (about 55%) was comparable with that of a solution of OSA suggesting that Si in beer is present chiefly in a monomeric form and is readily bioavailable.

Download Full-text

The comparative absorption of silicon from different foods and food supplements

British Journal Of Nutrition ◽

10.1017/s0007114509311757 ◽

2009 ◽

Vol 102 (6) ◽

pp. 825-834 ◽

Cited By ~ 87

Author(s):

Supannee Sripanyakorn ◽

Ravin Jugdaohsingh ◽

Wacharee Dissayabutr ◽

Simon H. C. Anderson ◽

Richard P. H. Thompson ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Optical Emission ◽

Positive Control ◽

Emission Spectrometry ◽

Orthosilicic Acid ◽

Green Beans ◽

Inductively Coupled ◽

Gastrointestinal Conditions ◽

Kinetics Of Dissolution

Dietary Si (orthosilicic acid; OSA) appears important in connective tissue health, and although the sources and intakes of Si are well established, its absorption is not. Si absorption was measured from eight high-Si-containing sources: alcohol-free beer; OSA solution (positive control); bananas; green beans; supplemental choline-stabilised OSA (ChOSA); supplemental monomethyl silanetriol (MMST); supplemental colloidal silica (CS); magnesium trisilicate British Pharmacopoeia antacid (MTBP). Two of the supplements and the antacid were pre-selected following an in vitro dissolution assay. Fasting, healthy subjects (CS, n 3; others, n ≥ 5) each ingested two of the sources separated by a 1-week wash-out period. Blood and urine were collected and measured for total Si concentrations by inductively coupled plasma optical emission spectrometry. Absorption, based on urinary Si excretion, was highest for MMST and alcohol-free beer (64 % of dose), followed by green beans (44 %), OSA (43 %), ChOSA (17 %), bananas and MTBP (4 %) and CS (1 %). Peak serum concentrations occurred by 0.5 h for MMST and green beans, 1.5 h for OSA and alcohol-free beer, 2 h for ChOSA and CS, and 4 h for MTBP. Area under the serum curves correlated positively with urinary Si output (r 0·82; P < 0·0001). Absorption of Si from supplements and antacids was consistent with their known chemical speciation and kinetics of dissolution under simulated gastrointestinal conditions. Monomeric silicates were readily absorbed, while particulate silicates were decreasingly well absorbed with increasing polymerisation. The present results highlight the need to allow for relative absorption of Si from different foods or supplements in subsequent epidemiological and intervention studies.

Download Full-text

Iron Redistribution Upon Thermokarst Processes in the Yedoma Domain

Frontiers in Earth Science ◽

10.3389/feart.2021.703339 ◽

2021 ◽

Vol 9 ◽

Author(s):

Arthur Monhonval ◽

Jens Strauss ◽

Elisabeth Mauclet ◽

Catherine Hirst ◽

Nathan Bemelmans ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Optical Emission ◽

The Arctic ◽

Emission Spectrometry ◽

Amorphous Oxides ◽

Inductively Coupled ◽

Lake Formation ◽

Significant Difference ◽

Induced Changes ◽

Flooding Events

Ice-rich permafrost has been subject to abrupt thaw and thermokarst formation in the past and is vulnerable to current global warming. The ice-rich permafrost domain includes Yedoma sediments that have never thawed since deposition during the late Pleistocene and Alas sediments that were formed by previous thermokarst processes during the Lateglacial and Holocene warming. Permafrost thaw unlocks organic carbon (OC) and minerals from these deposits and exposes OC to mineralization. A portion of the OC can be associated with iron (Fe), a redox-sensitive element acting as a trap for OC. Post-depositional thaw processes may have induced changes in redox conditions in these deposits and thereby affected Fe distribution and interactions between OC and Fe, with knock-on effects on the role that Fe plays in mediating present day OC mineralization. To test this hypothesis, we measured Fe concentrations and proportion of Fe oxides and Fe complexed with OC in unthawed Yedoma and previously thawed Alas deposits. Total Fe concentrations were determined on 1,292 sediment samples from the Yedoma domain using portable X-ray fluorescence; these concentrations were corrected for trueness using a calibration based on a subset of 144 samples measured by inductively coupled plasma optical emission spectrometry after alkaline fusion (R2 = 0.95). The total Fe concentration is stable with depth in Yedoma deposits, but we observe a depletion or accumulation of total Fe in Alas deposits, which experienced previous thaw and/or flooding events. Selective Fe extractions targeting reactive forms of Fe on unthawed and previously thawed deposits highlight that about 25% of the total Fe is present as reactive species, either as crystalline or amorphous oxides, or complexed with OC, with no significant difference in proportions of reactive Fe between Yedoma and Alas deposits. These results suggest that redox driven processes during past thermokarst formation impact the present-day distribution of total Fe, and thereby the total amount of reactive Fe in Alas versus Yedoma deposits. This study highlights that ongoing thermokarst lake formation and drainage dynamics in the Arctic influences reactive Fe distribution and thereby interactions between Fe and OC, OC mineralization rates, and greenhouse gas emissions.

Download Full-text

ICP/XRF Analysis for Trace Elements in Soil Samples from Gezira and Suki Schemes, Sudan

International Journal of Scientific Research and Management ◽

10.18535/ijsrm/v9i02.c01 ◽

2021 ◽

Vol 9 (02) ◽

pp. 32-39

Author(s):

Marwa M Adam ◽

Mustafa M Osman ◽

Ahmed Salih Elhag ◽

Mohamed A Elsheikh

Keyword(s):

Inductively Coupled Plasma ◽

Optical Emission ◽

Hierarchical Cluster ◽

Soil Samples ◽

Emission Spectrometry ◽

Inductively Coupled ◽

Elemental Concentrations ◽

Accuracy Of Measurements ◽

Significant Difference ◽

Plasma Optical Emission Spectrometry

In the present study, soil samples have been collected from two different agriculture areas: Gezira and Suki schemes in Sudan, The elemental concentrations for Cr, Ni, Cu, Zn, and Pb have been determined using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and X-ray Fluorescence spectrometry (XRF). The accuracy of measurements has been investigated by using ISE (PT) 1&4 and fortified samples for ICP, IAEA-Soil-7 XRF, respectively. A good agreement was found between certified and measured values. The average elemental concentrations by ICP of these elements Cr, Ni, Cu, Zn, and Pb in loc1 were found as follows: 84.7, 48.15, 33.5, 65.43, and 12.57 ppm, respectively. While the results obtained in loc2 were found as follows: 105, 65.1, 41.3, 55.4, and 12.74 ppm, respectively. The average elemental concentrations by XRF of these elements Cr, Ni, Cu, Zn, and Pb in loc1 were found as follows: 77.21, 43.72, 27.62, 86.96, and 18.74 ppm, respectively. While the results obtained in loc2 were found as follows: 123.33, 57.41, 35.99, 98.85, and 16.43 ppm, respectively. A statistical test (t-test) was applied to the data of both methods without any significant difference between the two techniques. The results obtained were compared to WHO permissible limits. Correlations between different elements were performed. Hierarchical cluster analysis was done for the data. The average elemental concentrations were calculated and compared with data from the literature.

Download Full-text

Silicon absorption and excretion is independent of age and sex in adults

British Journal Of Nutrition ◽

10.1017/s0007114513000184 ◽

2013 ◽

Vol 110 (6) ◽

pp. 1024-1030 ◽

Cited By ~ 9

Author(s):

Ravin Jugdaohsingh ◽

Supannee Sripanyakorn ◽

Jonathan J. Powell

Keyword(s):

Older Adults ◽

Inductively Coupled Plasma ◽

Optical Emission ◽

Emission Spectrometry ◽

Orthosilicic Acid ◽

Post Dose ◽

Baseline Serum ◽

Inductively Coupled ◽

Time To Peak ◽

Age And Sex

Host factors influencing the absorption and excretion of Si are poorly understood, although previous murine and human studies have suggested that age, sex and oestrogen status may affect Si metabolism and thus function. Here, serum and urine samples were collected from twenty-six healthy adults at baseline and over a 6 h period following ingestion of 17·4 mg Si (orthosilicic acid) and analysed by inductively coupled plasma optical emission spectrometry. Fasting baseline serum and urinary Si concentrations were marginally higher in older adults (51–66 years old) compared with young adults (20–47 years old); however, there was no difference in the absorption of Si into serum (overall profile, rate of Si appearance, peak concentration and time to peak) between the different adult groups. The rate of elimination of Si from serum did not significantly differ with age or sex, although serum concentration at 6 h was higher in older adults and significantly correlated with age (r 0·5; P= 0·01). There were, however, no significant differences in the excretion of Si into urine (a proxy for overall uptake) between the groups, averaging approximately 45 %. Oestradiol levels did not correlate with any of the above measures of Si. Thus, overall, host age and sex did not appear to markedly influence Si absorption or excretion in human adults and no correlations were found with serum oestradiol status. The marginally higher baseline and 6 h post-dose Si levels in older adults may reflect modestly impaired renal function and/or the loss of Si from connective tissues with ageing.

Download Full-text

Copper(II) and Sulfur Dioxide in Chardonnay Juice and Shiraz Must: Impact on Volatile Aroma Compounds and Cu Forms in Wine

Beverages ◽

10.3390/beverages5040070 ◽

2019 ◽

Vol 5 (4) ◽

pp. 70

Author(s):

Xinyi Zhang ◽

Nikolaos Kontoudakis ◽

John W. Blackman ◽

Andrew C. Clark

Keyword(s):

Inductively Coupled Plasma ◽

Grape Juice ◽

Optical Emission ◽

Emission Spectrometry ◽

Inductively Coupled ◽

Volatile Aldehyde ◽

Wine Composition ◽

Significant Difference ◽

Bottle Aging ◽

Plasma Optical Emission Spectrometry

This work outlines the influence of Cu(II) and SO2 concentrations in Chardonnay juice or Shiraz must on the respective wine composition. Analyses were conducted pre- and post-fermentation, after cold stabilization, after bentonite treatment (Chardonnay only), at bottling, and 15 months after bottling. The quantification of total Cu was conducted by inductively coupled plasma optical emission spectrometry and free Cu by stripping potentiometry. Low molecular weight sulfur compounds, volatile aldehyde compounds, and general volatile compounds, including esters and terpenes, were quantified with gas-chromatography- or liquid-chromatography-QQQ-mass spectrometry. For Chardonnay, increased Cu concentration in the juice resulted in higher concentrations of Cu in the respective wine, while Shiraz wines showed no significant difference. Increased Cu addition to Chardonnay juice also produced significantly higher concentrations of H2S, 3-methylbutanal, and methional, but lower concentrations of methanethiol and phenylacetaldehyde, while SO2 addition increased 3-methylbutanal and phenylacetaldehyde, and decreased methanethiol production from post-fermentation to post-bottle aging. For the Shiraz, SO2 led to higher concentrations of H2S, and both SO2 and Cu addition increased the concentrations of hexanal, 3-methylbutanal, and phenylacetaldehyde in wine, but this effect diminished after cold stabilization. This study shows that SO2 and Cu in grape juice/must can have long-term implications for wine composition.

Download Full-text