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Pua A, Goh RMV, Huang Y, Tang VCY, Ee KH, Cornuz M, Liu SQ, Lassabliere B, Yu B. Recent advances in analytical strategies for coffee volatile studies: Opportunities and challenges. Food Chem 2022; 388:132971. [PMID: 35462220 DOI: 10.1016/j.foodchem.2022.132971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/08/2022] [Accepted: 04/10/2022] [Indexed: 11/29/2022]
Abstract
Coffee has attracted significant research interest owing to its complex volatile composition and aroma, which imparts a pleasant sensorial experience that remains challenging to analyse and interpret. This review summarises analytical challenges associated with coffee's volatile and matrix complexity, and recent developments in instrumental techniques to resolve them. The benefits of state-of-the-art analytical techniques applied to coffee volatile analysis from experimental design to sample preparation, separation, detection, and data analysis are evaluated. Complementary method selection coupled with progressive experimental design and data analysis are vital to unravel the increasing comprehensiveness of coffee volatile datasets. Considering this, analytical workflows for conventional, targeted, and untargeted coffee volatile analyses are thus proposed considering the trends towards sorptive extraction, multidimensional gas chromatography, and high-resolution mass spectrometry. In conclusion, no single analytical method addresses coffee's complexity in its entirely, and volatile analysis must be tailored to the key objectives and concerns of the analyst.
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Affiliation(s)
- Aileen Pua
- Mane SEA Pte Ltd, 3 Biopolis Drive, #07-17/18/19 Synapse, Singapore 138623, Sigapore; Department of Food Science and Technology, National University of Singapore, S14 Level 5, Science Drive 2, Singapore 117542, Sigapore
| | - Rui Min Vivian Goh
- Mane SEA Pte Ltd, 3 Biopolis Drive, #07-17/18/19 Synapse, Singapore 138623, Sigapore
| | - Yunle Huang
- Mane SEA Pte Ltd, 3 Biopolis Drive, #07-17/18/19 Synapse, Singapore 138623, Sigapore; Department of Food Science and Technology, National University of Singapore, S14 Level 5, Science Drive 2, Singapore 117542, Sigapore
| | - Vivien Chia Yen Tang
- Mane SEA Pte Ltd, 3 Biopolis Drive, #07-17/18/19 Synapse, Singapore 138623, Sigapore
| | - Kim-Huey Ee
- Mane SEA Pte Ltd, 3 Biopolis Drive, #07-17/18/19 Synapse, Singapore 138623, Sigapore
| | - Maurin Cornuz
- Mane SEA Pte Ltd, 3 Biopolis Drive, #07-17/18/19 Synapse, Singapore 138623, Sigapore
| | - Shao Quan Liu
- Department of Food Science and Technology, National University of Singapore, S14 Level 5, Science Drive 2, Singapore 117542, Sigapore.
| | - Benjamin Lassabliere
- Mane SEA Pte Ltd, 3 Biopolis Drive, #07-17/18/19 Synapse, Singapore 138623, Sigapore
| | - Bin Yu
- Mane SEA Pte Ltd, 3 Biopolis Drive, #07-17/18/19 Synapse, Singapore 138623, Sigapore.
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Alafeef AK, Ariffin F, Zulkurnain M. Organic Selenium as Antioxidant Additive in Mitigating Acrylamide in Coffee Beans Roasted via Conventional and Superheated Steam. Foods 2020; 9:E1197. [PMID: 32872507 PMCID: PMC7555674 DOI: 10.3390/foods9091197] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 08/22/2020] [Accepted: 08/24/2020] [Indexed: 12/18/2022] Open
Abstract
Selenium is an essential micronutrient with significant antioxidant activity promising in mitigating the formation of acrylamide during high-temperature roasting. In this study, green coffee beans pretreated with selenium (Se-coffee) were investigated on their selenium uptake, selenium retention in green and roasted beans, antioxidant activities, and formation of acrylamide during conventional and superheated steam roasting. Comparisons were made with positive (pretreated without selenium) and negative (untreated) controls. The acrylamide formation was significantly inhibited in Se-coffee (108.9-165.3 μg/kg) compared to the positive and negative controls by 73.9% and 52.8%, respectively. The reduction of acrylamide by superheated steam roasting only observed in the untreated coffee beans (negative control) by 32.4% parallel to the increase in its antioxidant activity. Selenium pretreatment significantly increased antioxidant activity of the roasted Se-coffee beans after roasting although soaking pretreatment significantly reduced antioxidant activity in the green beans. Acrylamide reduction in the roasted coffee beans strongly correlated with the change in antioxidant capacities after roasting (∆FRAP, 0.858; ∆DPPH, 0.836). The results indicate that the antioxidant properties of the organic selenium suppressed acrylamide formation during coffee roasting.
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Affiliation(s)
| | - Fazilah Ariffin
- Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia; (A.K.A.); (M.Z.)
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Baldovini N, Chaintreau A. Identification of key odorants in complex mixtures occurring in nature. Nat Prod Rep 2020; 37:1589-1626. [PMID: 32692323 DOI: 10.1039/d0np00020e] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Covering: up to 2019Soon after the birth of gas chromatography, mass spectrometry and olfactometry were used as detectors, which allowed impressive development to be achieved in the area of odorant determinations. Since the mid-80s, structured methods of gas chromatography-olfactometry have appeared, allowing the determination of which odor constituents play a key role in materials. Progressively, numerous strategies have been proposed for sample preparation from raw materials, the representativeness evaluation of extracts, the identification of odor constituents, their quantification, and subsequently, the recombination of the key odorants to mimic the initial odor. However, the multiplicity of options at each stage of the analysis leads to a confusing landscape in this field, and thus, the present review aims at critically presenting the available options. For each step, the most frequently used alternatives are described, together with their strengths and weaknesses based on theoretical and experimental justifications according to the literature. These techniques are exemplified by many applications in the literature on aromas, fragrances and essential oils, with the initial focus on wine odorants, followed by a short overview on the molecular diversity of key odorants, which illustrates most of the facets and complexities of odor studies, including the issues raised by odorant interactions such as synergies.
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Affiliation(s)
- Nicolas Baldovini
- Institut de Chimie de Nice, Faculté des Sciences, Université Côte d'Azur, 06108 Nice Cedex 2, France.
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Messaoudi M, Begaa S, Hamidatou L, Salhi M. Determination of selenium in roasted beans coffee samples consumed in Algeria by radiochemical neutron activation analysis method. RADIOCHIM ACTA 2017. [DOI: 10.1515/ract-2017-2782] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The essential trace element selenium is a focus of attention due to its effects on human health, there being consequences of both its deficiency and excess. Due to the ultra-trace content of selenium, the neutron activation analysis method (NAA) is difficult to apply. We therefore made use of the radiochemical neutron activation analysis (RNAA) to determine Se at low level concentrations in several consumed food items in Algeria. A radiochemical procedure based on liquid–liquid separation was established in our laboratory. In this research we focused on the determination of selenium in two species of coffee: Arabica and Robusta. The accuracy of the method was assessed by analyzing the certified reference material NIST-SRM 1573a (tomato leaves). The results obtained show a selenium variation from 0.025 to 0.052 μg/g in coffee beans and an average yield of the separation of about 85%. The results of this study were compared with those obtained with samples from Brazilian, Caribbean, Indian and Kenyan coffee beans.
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Affiliation(s)
- Mohammed Messaoudi
- Nuclear Research Centre of Birine , P.O. Box 180, Ain Oussera , 17200 Djelfa , Algeria
| | - Samir Begaa
- Nuclear Research Centre of Birine , P.O. Box 180, Ain Oussera , 17200 Djelfa , Algeria
| | - Lylia Hamidatou
- Nuclear Research Centre of Birine , P.O. Box 180, Ain Oussera , 17200 Djelfa , Algeria
| | - M’hamed Salhi
- Nuclear Research Centre of Birine , P.O. Box 180, Ain Oussera , 17200 Djelfa , Algeria
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5
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Quantification of volatile-alkylated selenium and sulfur in complex aqueous media using solid-phase microextraction. J Chromatogr A 2015; 1407:11-20. [PMID: 26150251 DOI: 10.1016/j.chroma.2015.06.054] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 06/16/2015] [Accepted: 06/19/2015] [Indexed: 01/20/2023]
Abstract
Biologically produced volatile-alkylated Se and S compounds play an important role in the global biogeochemical Se and S cycles, are important constituents of odorous industrial emissions, and contribute to (off-)flavors in food and beverages. This study presents a fully automated direct-immersion solid-phase microextraction (DI-SPME) method coupled with capillary gas chromatography-mass spectrometry (GC/MS) for the simultaneous quantification of 10 volatile-alkylated Se and S compounds in complex aqueous media. Instrumental parameters of the SPME procedure were optimized to yield extraction efficiencies of up to 96% from complex aqueous matrices. The effects of sample matrix composition and analyte transformation during sample storage were critically assessed. With the use of internal standards and procedural calibrations, the DI-SPME-GC/MS method allows for trace-level quantification of volatile Se and S compounds in the ng/L range (e.g. down to 30 ng/L dimethyl sulfide and 75 ng/L dimethyl selenide). The applicability and robustness of the presented method demonstrate that the method may be used to quantify volatile Se and S compounds in complex aqueous samples, such as industrial effluents or food and beverage samples.
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Bodnar M, Szczyglowska M, Konieczka P, Namiesnik J. Methods of Selenium Supplementation: Bioavailability and Determination of Selenium Compounds. Crit Rev Food Sci Nutr 2014; 56:36-55. [DOI: 10.1080/10408398.2012.709550] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Fischer MJ, Beatty AM. Solid phase microextraction (SPME) combined with TGA as a technique for guest analysis in crystal engineering. CrystEngComm 2014. [DOI: 10.1039/c4ce00419a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Guest identification using SPME – a technique for analysis of TGA off-gas that eliminates the need for direct TGA-GC/MS coupling.
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Affiliation(s)
- Matthew J. Fischer
- Department of Chemistry and Biochemistry and the Center for Nanoscience
- University of Missouri-St. Louis
- , USA
| | - Alicia M. Beatty
- Department of Chemistry and Biochemistry and the Center for Nanoscience
- University of Missouri-St. Louis
- , USA
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8
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Yin Y, Liu J, Jiang G. Recent advances in speciation analysis of mercury, arsenic and selenium. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/s11434-012-5497-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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9
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A method for analysis of dimethyl selenide and dimethyl diselenide by LC-ICP-DRC-MS. Anal Bioanal Chem 2010; 398:3081-6. [DOI: 10.1007/s00216-010-4242-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 09/19/2010] [Accepted: 09/21/2010] [Indexed: 11/25/2022]
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10
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Gabel-Jensen C, Lunøe K, Gammelgaard B. Formation of methylselenol, dimethylselenide and dimethyldiselenide in in vitro metabolism models determined by headspace GC-MS. Metallomics 2010; 2:167-73. [DOI: 10.1039/b914255j] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Matich AJ, McKenzie MJ, Brummell DA, Rowan DD. Organoselenides from Nicotiana tabacum genetically modified to accumulate selenium. PHYTOCHEMISTRY 2009; 70:1098-1106. [PMID: 19570557 DOI: 10.1016/j.phytochem.2009.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Revised: 05/28/2009] [Accepted: 06/01/2009] [Indexed: 05/08/2023]
Abstract
Nicotiana tabacum L. (tobacco) plants were transformed to overexpress a selenocysteine methyltransferase gene from the selenium hyperaccumulator Astragalus bisulcatus (Hook.) A. Gray (two-grooved milkvetch), and an ATP-sulfurylase gene from Brassica oleracea L. var. italica (broccoli). Solvent extraction of leaves harvested from plants treated with selenate revealed five selenium-containing compounds, of which four were identified by chemical synthesis as 2-(methylseleno)acetaldehyde, 2,2-bis(methylseleno)acetaldehyde, 4-(methylseleno)-(2E)-nonenal, and 4-(methylseleno)-(2E,6Z)-nonadienal. These four compounds have not previously been reported in nature.
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Affiliation(s)
- Adam J Matich
- The New Zealand Institute for Plant and Food Research Limited (Plant and Food Research), Private Bag 11600, Palmerston North 4442, New Zealand.
| | - Marian J McKenzie
- The New Zealand Institute for Plant and Food Research Limited (Plant and Food Research), Private Bag 11600, Palmerston North 4442, New Zealand
| | - David A Brummell
- The New Zealand Institute for Plant and Food Research Limited (Plant and Food Research), Private Bag 11600, Palmerston North 4442, New Zealand
| | - Daryl D Rowan
- The New Zealand Institute for Plant and Food Research Limited (Plant and Food Research), Private Bag 11600, Palmerston North 4442, New Zealand
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12
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Novel approaches for selenium speciation in foodstuffs and biological specimens: A review. Anal Chim Acta 2009; 634:135-52. [DOI: 10.1016/j.aca.2008.12.026] [Citation(s) in RCA: 206] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 11/06/2008] [Accepted: 12/15/2008] [Indexed: 11/21/2022]
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13
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Tao H, Nakazato T. A Test Method for Determining Volatility and Degradability of Polybrominated Diphenylethers Using Headspace/Gas Chromatograph/Inductively Coupled Plasma Mass Spectrometer. BUNSEKI KAGAKU 2009. [DOI: 10.2116/bunsekikagaku.58.363] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Hiroaki Tao
- National Institute of Advanced Industrial Science and Technology (AIST)
| | - Tetsuya Nakazato
- National Institute of Advanced Industrial Science and Technology (AIST)
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14
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Headspace solid-phase microextraction-gas chromatographic-time-of-flight mass spectrometric methodology for geographical origin verification of coffee. Anal Chim Acta 2008; 617:72-84. [PMID: 18486643 DOI: 10.1016/j.aca.2008.04.009] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Revised: 03/25/2008] [Accepted: 04/01/2008] [Indexed: 11/22/2022]
Abstract
Increasing consumer awareness of food safety issues requires the development of highly sophisticated techniques for the authentication of food commodities. The food products targeted for falsification are either products of high commercial value or those produced in large quantities. For this reason, the present investigation is directed towards the characterization of coffee samples according to the geographical origin. The conducted research involves the development of a rapid headspace solid-phase microextraction (HS-SPME)-gas chromatography-time-of-flight mass spectrometry (GC-TOFMS) method that is utilized for the verification of geographical origin traceability of coffee samples. As opposed to the utilization of traditional univariate optimization methods, the current study employs the application of multivariate experimental designs to the optimization of extraction-influencing parameters. Hence, the two-level full factorial first-order design aided in the identification of two influential variables: extraction time and sample temperature. The optimum set of conditions for the two variables was 12 min and 55 degrees C, respectively, as directed by utilization of Doehlert matrix and response surface methodology. The high-throughput automated SPME procedure was completed by implementing a single divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) 50/30 microm metal fiber with excellent durability properties ensuring the completion of overall sequence of coffee samples. The utilization of high-speed TOFMS instrument ensured the completion of one GC-MS run of a complex coffee sample in 7.9 min and the complete list of benefits provided by ChromaTOF software including fully automated background subtraction, baseline correction, peak find and mass spectral deconvolution algorithms was exploited during the data evaluation procedure. The combination of the retention index (RI) system using C(8)-C(40) alkanes and the mass spectral library search was utilized for the confirmation of analyte identity in the reference authentic Brazilian coffee sample. The semi-quantitative results were then submitted to statistical evaluation, namely principal component analysis (PCA) for the establishment of geographical origin discriminations.
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15
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Simultaneous determination of selenium and arsenic contents in different extracts of Radix Astragali by enhancement effect of ethanol in hydride generation-inductively coupled plasma-atomic emission spectrometry. Microchem J 2007. [DOI: 10.1016/j.microc.2007.04.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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16
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Campillo N, Peñalver R, Hernández-Córdoba M, Pérez-Sirvent C, Martínez-Sánchez MJ. Comparison of two derivatizing agents for the simultaneous determination of selenite and organoselenium species by gas chromatography and atomic emission detection after preconcentration using solid-phase microextraction. J Chromatogr A 2007; 1165:191-9. [PMID: 17692323 DOI: 10.1016/j.chroma.2007.07.064] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Revised: 07/23/2007] [Accepted: 07/26/2007] [Indexed: 11/15/2022]
Abstract
Two methods for the simultaneous determination of selenite and two organoselenium compounds, dimethylselenide (DMSe) and dimethyldiselenide (DMDSe), are proposed. Both methods involve sample preconcentration by solid-phase microextraction (SPME) and capillary gas chromatography coupled to atomic emission detection (GC-AED). The main difference between the methods is the derivatizing agent used to complex the inorganic species: sodium tetraethylborate and 4,5-dichloro-1,2-phenylenediamine. The parameters affecting the derivatization and preconcentration steps, chromatographic separation as well as detection of the compounds were optimized. Direct immersion (DI) mode and a relatively long extraction time were selected for the method involving the formation of the piazselenol complex, better sensitivity being achieved for the three analytes under study. In this case, detection limits ranged between 3 and 25 ng L(-1), depending on the compound. Headspace mode (HS) and extraction times of 20 min were selected for the method involving tetraalkylborate, and detection limits of between 7.3 and 55 ng L(-1) were obtained. DMSe and Se(IV) were found in several of the water samples analyzed at concentrations of 0.07-1.0 ng mL(-1).
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Affiliation(s)
- Natalia Campillo
- Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia, Spain
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Gomes-Junior RA, Gratão PL, Gaziola SA, Mazzafera P, Lea PJ, Azevedo RA. Selenium-induced oxidative stress in coffee cell suspension cultures. FUNCTIONAL PLANT BIOLOGY : FPB 2007; 34:449-456. [PMID: 32689372 DOI: 10.1071/fp07010] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2007] [Accepted: 03/28/2007] [Indexed: 05/07/2023]
Abstract
Selenium (Se) is an essential element for humans and animals that is required for key antioxidant reactions, but can be toxic at high concentrations. We have investigated the effect of Se in the form of selenite on coffee cell suspension cultures over a 12-day period. The antioxidant defence systems were induced in coffee cells grown in the presence of 0.05 and 0.5 mm sodium selenite (Na2SeO3). Lipid peroxidation and alterations in antioxidant enzymes were the main responses observed, including a severe reduction in ascorbate peroxidase activity, even at 0.05 mm sodium selenite. Ten superoxide dismutase (SOD) isoenzymes were detected and the two major Mn-SOD isoenzymes (bands V and VI) responded more to 0.05 mm selenite. SOD band V exhibited a general decrease in activity after 12 h of treatment with 0.05 mm selenite, whereas band VI exhibited the opposite behavior and increased in activity. An extra isoenzyme of glutathione reductase (GR) was induced in the presence of selenite, which confirmed our previous results obtained with Cd and Ni indicating that this GR isoenzyme may have the potential to be a marker for oxidative stress in coffee.
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Affiliation(s)
- Rui A Gomes-Junior
- Centro de Estudos Superiores de Balsas, Universidade Estadual do Maranhão, 65800-000, Balsas, MA, Brazil
| | - Priscila L Gratão
- Departamento de Genética, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, 13418-900 Piracicaba, SP, Brazil
| | - Salete A Gaziola
- Departamento de Genética, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, 13418-900 Piracicaba, SP, Brazil
| | - Paulo Mazzafera
- Departamento de Fisiologia Vegetal, Instituto de Biologia, CP 6109, Universidade Estadual de Campinas, 13083-970 Campinas, SP, Brazil
| | - Peter J Lea
- Department of Biological Sciences, University of Lancaster, Lancaster, LA1 4YQ, UK
| | - Ricardo A Azevedo
- Departamento de Genética, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, 13418-900 Piracicaba, SP, Brazil
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Shah M, Meija J, Caruso JA. Relative Mass Defect Filtering of High-Resolution Mass Spectra for Exploring Minor Selenium Volatiles in Selenium-Enriched Green Onions. Anal Chem 2007; 79:846-53. [PMID: 17263309 DOI: 10.1021/ac060703k] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, the presence of minor Se-containing volatiles in Se-enriched green onions (Allium fistulosum) was investigated using the combination of high-resolution mass spectrometry, inductively coupled plasma mass spectrometry, and a simple relative mass defect-based algorithm to aid trace level analysis of unknown components. This confirmed the structures of volatiles reported previously, along with several unreported small molecular weight Se-containing volatiles from plants, such as MeSeSeSMe. This data analysis technique was also useful to link the results obtained from molecular and elemental mass spectrometry thus aiding in the search for new trace level Se-containing volatiles.
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Affiliation(s)
- Monika Shah
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, USA
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B'Hymer C, Caruso JA. Selenium speciation analysis using inductively coupled plasma-mass spectrometry. J Chromatogr A 2006; 1114:1-20. [PMID: 16551466 DOI: 10.1016/j.chroma.2006.02.063] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Revised: 02/14/2006] [Accepted: 02/21/2006] [Indexed: 10/24/2022]
Abstract
Selenium exists in several oxidation states and a variety of inorganic and organic compounds, and the chemistry of selenium is complex in both the environment and living systems. Selenium is an essential element at trace levels and toxic at greater levels. Interest in speciation analysis for selenium has grown rapidly in this last decade, especially in the use of chromatographic separation coupled with inductively coupled plasma-mass spectrometry (ICP-MS). Complete characterization of selenium compounds is necessary to understand selenium's significance in metabolic processes, clinical chemistry, biology, toxicology, nutrition and the environment. This review describes some of the essential background of selenium, and more importantly, some of the currently used separation methodologies, both chromatographic and electrophoretic, with emphasis on applications of selenium speciation analysis using ICP-MS detection.
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Affiliation(s)
- C B'Hymer
- Department of Chemistry, University of Cincinnati, Mail location 0172, Cincinnati, OH 45221-0172, USA
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Meija J, Caruso JA. Selenium and sulfur trichalcogenides from the chalcogenide exchange reaction. Inorg Chem 2004; 43:7486-92. [PMID: 15530099 DOI: 10.1021/ic0494206] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Various selenium- and sulfur-containing volatiles have been detected and characterized as products of chalcogen exchange reactions. The formation of all possible selenium- and sulfur-containing trichalcogenide isomers (-SeSS-, -SSeS-, -SeSeS-, -SeSSe- and -SeSeSe-) was observed at room temperature in the solutions containing diselenide and trisulfide. Because of the low activation barrier of the selenium exchange reaction, these species are expected also to form in biological systems in the presence of diselenides and higher sulfides. Methyl and ethyl derivatives of these species were characterized using gas chromatography coupled to time-of-flight mass spectrometry with electron impact, chemical, and field ionization. Rearrangements of triselenides lead also to the formation of isomeric branched-structure triselenides, selanadiselenides. Because of the very similar structural properties, the behavior of these novel species was studied under various ionization modes (EI+, CI+, EI-, and CI-).
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Affiliation(s)
- Juris Meija
- Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221-0172, USA
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Meija J, Beck TL, Caruso JA. Interpretation of alkyl diselenide and selenosulfenate mass spectra. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2004; 15:1325-1332. [PMID: 15337513 DOI: 10.1016/j.jasms.2004.05.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2003] [Revised: 05/18/2004] [Accepted: 05/18/2004] [Indexed: 05/24/2023]
Abstract
The mass spectral fragmentation of aliphatic diselenides and selenosulfenates is analyzed to gain a better understanding of the behavior of these species. The main fragmentation pathways of these species include the fragmentation along the Se?C bond, fragmentation along the Se?Se or Se?S bonds and intra-molecular rearrangements. In general, negative ionization favors the fragmentation along the Se?Se or Se?S bonds while positive ionization leads to stable molecular ions. Density functional theory calculations of bond dissociation energies and molecular orbital analysis was undertaken to explain the observed trends in molecular fragmentation. Besides the analysis of molecular fragmentation, a phenomenon of molecular association in negative electron impact and positive chemical ionization conditions was observed and investigated using a high resolution time-of-flight mass spectrometer. Molecular association that occurs during the ionization of species includes the formation of symmetrical diselenides from asymmetrical selenosulfenates and formation of alkylseleno adducts from the corresponding diselenides. For species which is hard to resolve by mass analysis, such as isobars of CHSe, CH(2)Se, and CH(3)Se, the isotope pattern superimposition procedure was applied to define the overlapping clusters.
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Affiliation(s)
- Juris Meija
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, USA
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