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Li A, Abrahim A, Islam M, Mejías E, Hafizati Abdul Halim N, Frew R, Vlachou C, Kelly SD. A new approach to detecting sugar syrup addition to honey: Stable isotope analysis of hexamethylenetetramine synthesised from honey monosaccharides (fructose and glucose). Food Chem 2024; 434:137451. [PMID: 37748289 DOI: 10.1016/j.foodchem.2023.137451] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/10/2023] [Accepted: 09/08/2023] [Indexed: 09/27/2023]
Abstract
One of the most common types of adulteration of honey involves the addition of invert sugar syrups. A new method was developed to measure the stable isotope ratios of carbon and carbon-bound non-exchangeable (CBNE) hydrogen from specific molecular positions in fructose and glucose in honey. This was achieved through periodate oxidation of the sugars to produce formaldehyde, followed by reaction with ammonia to form hexamethylenetetramine (HMT). The preparation was simplified, optimized, and validated by isotopic analysis of replicate syntheses of HMT from fructose, glucose, sugar syrup and a representative authentic honey sample. The optimized method had a repeatability standard deviation from 1.5‰ to 3.0‰ and from 0.1‰ to 0.4‰ for δ2H and δ13C, respectively. This methodology has advantages over alternative isotopic methods, for measuring CBNE hydrogen isotope ratios in sugars, in terms of time, sensitivity and operability and offers a complementary method to differentiate authentic honey from invert sugar syrups.
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Affiliation(s)
- An Li
- Food Safety and Control Laboratory Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna International Centre, Wagramer Strasse 5, PO Box 100, 1400 Vienna, Austria; Institute of Quality Standards and Testing Technology, Beijing Academy of Agriculture and Forestry Sciences, 100097 Beijing, China
| | - Aiman Abrahim
- Food Safety and Control Laboratory Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna International Centre, Wagramer Strasse 5, PO Box 100, 1400 Vienna, Austria
| | - Marivil Islam
- Food Safety and Control Laboratory Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna International Centre, Wagramer Strasse 5, PO Box 100, 1400 Vienna, Austria
| | - Enrique Mejías
- Nuclear Technologies Center in Vulnerable Ecosystems, Nuclear Research and Applications Division, Chilean Nuclear Energy Commission, Santiago, Chile
| | | | - Russell Frew
- Oritain Global Limited, Dunedin, Otago 9016, New Zealand
| | - Christina Vlachou
- Food Safety and Control Laboratory Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna International Centre, Wagramer Strasse 5, PO Box 100, 1400 Vienna, Austria
| | - Simon D Kelly
- Food Safety and Control Laboratory Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna International Centre, Wagramer Strasse 5, PO Box 100, 1400 Vienna, Austria.
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2
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Gatzert X, Chun KP, Hermanowski R, Mäder R, Breuer L, Gattinger A, Orlowski N. Application of multiple stable isotopes to aid identification of the origin of regional and organic animal products in Hesse, Germany. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2023; 59:490-510. [PMID: 37981783 DOI: 10.1080/10256016.2023.2273941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 10/09/2023] [Indexed: 11/21/2023]
Abstract
There is an increasing global demand for regional and organic produce. However, the growth of these markets depends on consumers' trust. Thus, novel methods must be developed to aid the verification of the origin of produce. We built on our previous study to identify the geographical origin and production method of animal-derived food products. Thirty-samples of eggs, 99 of milk, 34 of beef, and 62 of pork were collected from different regions in central Germany and analysed for their stable isotopic composition. The analysis followed a single-variate authentification approach using five isotope signatures, δ18O, δ2H, δ13C, δ15N, and δ34S. The best-performing indicators for verification of the geographical origin were δ15N and δ34S for beef; δ18O, δ2H, and δ13C for milk, and δ2H and δ13C for pork. These tracers indicated statistically significant differences among regions with the exception of pork; the results recorded for eggs were inconclusive. It was possible to distinguish between production methods by means of δ15N and δ34S (beef); all five tracers (eggs), and δ13C, δ15N, and δ34S (milk). This study demonstrated how the analysis of stable isotopes can be employed to determine the geographic region of origin and production method of animal-derived products in Germany.
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Affiliation(s)
- Xenia Gatzert
- Research Institute of Organic Agriculture (FiBL), Frankfurt am Main, Germany
- Institute for Plant Production and Plant Breeding II - Organic Farming with Focus on Sustainable Soil Use, Justus Liebig University Giessen, Giessen, Germany
| | - Kwok P Chun
- Department of Geography and Environmental Management, University of the West of England, Bristol, UK
| | - Robert Hermanowski
- Research Institute of Organic Agriculture (FiBL), Frankfurt am Main, Germany
| | - Rolf Mäder
- Research Institute of Organic Agriculture (FiBL), Frankfurt am Main, Germany
| | - Lutz Breuer
- Institute for Landscape Ecology and Resources Management (ILR), Research Centre for BioSystems, Land Use and Nutrition (iFZ), Justus Liebig University Giessen, Giessen, Germany
- Center for Sustainable Food Systems, Justus Liebig University Giessen, Giessen, Germany
| | - Andreas Gattinger
- Institute for Plant Production and Plant Breeding II - Organic Farming with Focus on Sustainable Soil Use, Justus Liebig University Giessen, Giessen, Germany
- Center for Sustainable Food Systems, Justus Liebig University Giessen, Giessen, Germany
| | - Natalie Orlowski
- Chair of Hydrology, Faculty of Environment and Natural Resources, University of Freiburg, Freiburg, Germany
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3
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Díaz-Galiano FJ, Heinzen H, Gómez-Ramos MJ, Murcia-Morales M, Fernández-Alba AR. Identification of novel unique mānuka honey markers using high-resolution mass spectrometry-based metabolomics. Talanta 2023; 260:124647. [PMID: 37172434 DOI: 10.1016/j.talanta.2023.124647] [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: 03/05/2023] [Revised: 05/02/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023]
Abstract
Mānuka honey is a valuable commodity produced by bees foraging the flowers of Leptospermum scoparium, a bush native to New Zealand and Australia. Due to its high value and proven health benefits, authenticity fraud in the sale of this food is a significant risk, as recounted in the literature. Four compulsory natural products must be present at minimum concentrations to authenticate mānuka honey (3-phenyllactic acid, 2'-methoxyacetophenone, 2-methoxybenzoic acid, and 4-hydroxyphenyllactic acid). However, spiking other kinds of honey with these compounds and/or the dilution of mānuka honey with other varieties may result in fraud going undetected. In this work, liquid chromatography coupled with high-resolution mass spectrometry and a metabolomics-based strategy has allowed us to tentatively identify 19 natural products -putative mānuka honey markers-, nine of which are reported for the first time. Chemometric models applied to these markers allowed the detection of both spiking and dilution fraud attempts of mānuka honey, even at 75% mānuka honey purity. Thus, the herein-reported methodology can be employed in the prevention and detection of mānuka honey adulteration even at low levels, and the tentatively identified markers presented in this work proved valuable for mānuka honey authentication procedures.
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Affiliation(s)
- Francisco José Díaz-Galiano
- University of Almería, Department of Physics and Chemistry, Agrifood Campus of International Excellence (ceiA3), Ctra. Sacramento s/n, La Cañada de San Urbano, 04120, Almería, Spain
| | - Horacio Heinzen
- Pharmacognosy & Nat. Products, DQO, Facultad de Química Universidad de la República, Gral. Flores 2124, Montevideo, Uruguay
| | - María José Gómez-Ramos
- University of Almería, Department of Physics and Chemistry, Agrifood Campus of International Excellence (ceiA3), Ctra. Sacramento s/n, La Cañada de San Urbano, 04120, Almería, Spain
| | - María Murcia-Morales
- University of Almería, Department of Physics and Chemistry, Agrifood Campus of International Excellence (ceiA3), Ctra. Sacramento s/n, La Cañada de San Urbano, 04120, Almería, Spain
| | - Amadeo R Fernández-Alba
- University of Almería, Department of Physics and Chemistry, Agrifood Campus of International Excellence (ceiA3), Ctra. Sacramento s/n, La Cañada de San Urbano, 04120, Almería, Spain.
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4
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Hegazi NM, Elghani GEA, Farag MA. The super-food Manuka honey, a comprehensive review of its analysis and authenticity approaches. JOURNAL OF FOOD SCIENCE AND TECHNOLOGY 2021; 59:2527-2534. [DOI: 10.1007/s13197-021-05181-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 05/30/2021] [Accepted: 06/15/2021] [Indexed: 11/25/2022]
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5
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The Validity of Protein in Australian Honey as an Internal Standard for C4 Sugar Adulteration. FOOD ANAL METHOD 2021. [DOI: 10.1007/s12161-020-01938-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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6
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Kato Y, Kishi Y, Okano Y, Kawai M, Shimizu M, Suga N, Yakemoto C, Kato M, Nagata A, Miyoshi N. Methylglyoxal binds to amines in honey matrix and 2'-methoxyacetophenone is released in gaseous form into the headspace on the heating of manuka honey. Food Chem 2020; 337:127789. [PMID: 32795863 DOI: 10.1016/j.foodchem.2020.127789] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 07/31/2020] [Accepted: 08/04/2020] [Indexed: 10/23/2022]
Abstract
Reports on the thermal stability of manuka honey in terms of food processing have been few. This study investigated changes in nine characteristic chemicals of manuka honey during heating. Among these, methylglyoxal (MGO) and 2'-methoxyacetophenone (MAP) were significantly decreased by heating at 90 °C. To elucidate the mechanism for this decrease, artificial honey was prepared from sugars and water with MAP or MGO and then heated. The decrease of MGO was enhanced with l-proline, lysine, or arginine derivatives, accompanied by formation of 2-acetyl-1-pyrroline, MGO-derived lysine dimer, or argpyrimidine, respectively, suggesting that an amino-carbonyl reaction is one pathway for the loss of MGO. The decrease of MAP in the artificial honey depended on the volume of headspace in a vessel. MAP from heated manuka honey was also detected in the gas phase, indicating that MAP was vaporized. Heating could thus reduce the beneficial and/or signature molecules in honey.
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Affiliation(s)
- Yoji Kato
- School of Human Science and Environment, University of Hyogo, Himeji, Hyogo 670-0092, Japan; Research Institute for Food and Nutritional Sciences, University of Hyogo, Himeji, Hyogo 670-0092, Japan.
| | - Yui Kishi
- School of Human Science and Environment, University of Hyogo, Himeji, Hyogo 670-0092, Japan
| | - Yayako Okano
- School of Human Science and Environment, University of Hyogo, Himeji, Hyogo 670-0092, Japan
| | - Masaki Kawai
- School of Human Science and Environment, University of Hyogo, Himeji, Hyogo 670-0092, Japan
| | - Michiyo Shimizu
- School of Human Science and Environment, University of Hyogo, Himeji, Hyogo 670-0092, Japan
| | - Naoko Suga
- School of Human Science and Environment, University of Hyogo, Himeji, Hyogo 670-0092, Japan
| | - Chisato Yakemoto
- School of Human Science and Environment, University of Hyogo, Himeji, Hyogo 670-0092, Japan
| | - Mai Kato
- School of Food and Nutritional Sciences, University of Shizuoka, Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Akika Nagata
- School of Food and Nutritional Sciences, University of Shizuoka, Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Noriyuki Miyoshi
- School of Food and Nutritional Sciences, University of Shizuoka, Yada, Suruga-ku, Shizuoka 422-8526, Japan
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7
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Setijadi CH, Felix JN, Ellis HC, Alumbro JSS, Bello G, Dumancas GG. Development of a Facile and Convenient Method for Sugar Determination in Low Moisture Confectioneries and Honeys Using Fourier Transform Infrared Attenuated Total Reflectance Spectroscopy and Chemometrics. ANAL LETT 2020. [DOI: 10.1080/00032719.2020.1712605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Catherine H. Setijadi
- Department of Mathematics and Physical Sciences, Louisiana State University - Alexandria, Alexandria, LA, USA
| | - Jonathan N. Felix
- Department of Mathematics and Physical Sciences, Louisiana State University - Alexandria, Alexandria, LA, USA
| | - Helena C. Ellis
- Department of Mathematics and Physical Sciences, Louisiana State University - Alexandria, Alexandria, LA, USA
| | | | - Ghalib Bello
- MRC London Institute of Medical Sciences, London, United Kingdom
| | - Gerard G. Dumancas
- Department of Mathematics and Physical Sciences, Louisiana State University - Alexandria, Alexandria, LA, USA
- Department of Chemistry, University of the Philippines Visayas, Iloilo, Philippines
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8
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Chernyshev A, Braggins T. Investigation of Temporal Apparent C4 Sugar Change in Manuka Honey. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:4261-4267. [PMID: 32159341 DOI: 10.1021/acs.jafc.9b06965] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
New Zealand manuka honeys are known for their propensity to increase apparent C4 sugar content during storage. Depending on the particular storage regime and the initial content of dihydroxyacetone (DHA) in honey, the ready-to-market product often fails the C4 sugar test because of the above phenomenon. We have used DHA labeled with a radioactive 14C isotope in a set of honeys subject to an incubation experiment. These honeys were analyzed for DHA, methylglyoxal (MG), hydroxymethylfurfural (HMF), apparent C4 sugars, and 14C scintillation counts over a period of 18 months. The major conclusion of this experiment is that neither DHA nor MG is responsible for the δ13C shift in the honey protein extract. There must be some other yet unknown substance of manuka honey, which binds to the protein and causes negative δ13C shift. One identified candidate for such a binding is carbon dioxide.
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Affiliation(s)
- Anatoly Chernyshev
- Analytica Laboratories Ltd., Ruakura Research Centre, 10 Bisley Rd, Hamilton 3240, New Zealand
| | - Terry Braggins
- Analytica Laboratories Ltd., Ruakura Research Centre, 10 Bisley Rd, Hamilton 3240, New Zealand
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10
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Zhou X, Taylor MP, Salouros H, Prasad S. Authenticity and geographic origin of global honeys determined using carbon isotope ratios and trace elements. Sci Rep 2018; 8:14639. [PMID: 30279546 PMCID: PMC6168535 DOI: 10.1038/s41598-018-32764-w] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 09/14/2018] [Indexed: 01/07/2023] Open
Abstract
Honey is the world's third most adulterated food. The addition of cane sugar or corn syrup and the mislabelling of geographic origin are common fraudulent practices in honey markets. This study examined 100 honey samples from Australia (mainland and Tasmania) along with 18 other countries covering Africa, Asia, Europe, North America and Oceania. Carbon isotopic analyses of honey and protein showed that 27% of commercial honey samples tested were of questionable authenticity. The remaining 69 authentic samples were subject to trace element analysis for geographic determination. One-way ANOVA analysis showed a statistical difference (p < 0.05) in trace element concentrations of honey from Australian regions and different continents. Principal component analysis (PCA) and canonical discriminant analysis (CDA) coupled with C5.0 classification modelling of honey carbon isotopes and trace element concentrations showed distinct clusters according to their geographic origin. The C5.0 model revealed trace elements Sr, P, Mn and K can be used to differentiate honey according to its geographic origin. The findings show the common and prevalent issues of honey authenticity and the mislabelling of its geographic origin can be identified using a combination of stable carbon isotopes and trace element concentrations.
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Affiliation(s)
- Xiaoteng Zhou
- Department of Environmental Sciences, Faculty of Science and Engineering, Macquarie University, North Ryde, Sydney, New South Wales, 2109, Australia.
| | - Mark Patrick Taylor
- Department of Environmental Sciences, Faculty of Science and Engineering, Macquarie University, North Ryde, Sydney, New South Wales, 2109, Australia.
- Energy and Environmental Contaminants Research Centre, Macquarie University, North Ryde, Sydney, New South Wales, 2109, Australia.
| | - Helen Salouros
- Australian Forensic Drug Laboratory, National Measurement Institute, North Ryde, Sydney, New South Wales, 2113, Australia
| | - Shiva Prasad
- Analytical Service Branch, National Measurement Institute, North Ryde, Sydney, New South Wales, 2113, Australia
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11
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1H-NMR Profiling and Chemometric Analysis of Selected Honeys from South Africa, Zambia, and Slovakia. Molecules 2018; 23:molecules23030578. [PMID: 29510542 PMCID: PMC6017463 DOI: 10.3390/molecules23030578] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/18/2018] [Accepted: 01/23/2018] [Indexed: 12/14/2022] Open
Abstract
Honey is the natural sweet substance produced by honeybee from nectar or honeydew, exhibiting several nutritional and health benefits. It contains a complex mixture of compounds in different proportions, with sugars being the main component. The physicochemical characteristics of ten honeys were evaluated; represented by five, three, and two from South Africa, Slovakia, and Zambia, respectively. The range of values for the pH (3.75–4.38), electrical conductivity (99–659 µS/cm), and moisture content (14.2–17.7%) are within the recommended limits for quality honeys. 1H-NMR (Nuclear Magnetic Resonance) profiling of the honeys in D2O was determined, and the data were analysed by chemometrics. This method is fast, reproducible, and sample pre-treatment is not necessary. The 1H-NMR fingerprints of various chemical shift regions showed similarity or dissimilarity across geographical origins that are useful for identification, detection of adulteration, and quality control. The principal component analysis PCA and partial linear square discriminant analysis PLS-DA of the 1H-NMR profiles successively categorises the honeys into two chemically related groups. The R2 values are higher than the corresponding Q2 values for all samples, confirming the reliability of the model. Honeys in the same cluster contain similar metabolites and belong to the same botanic or floral origin.
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12
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Dong H, Xiao K, Xian Y, Wu Y. Authenticity determination of honeys with non-extractable proteins by means of elemental analyzer (EA) and liquid chromatography (LC) coupled to isotope ratio mass spectroscopy (IRMS). Food Chem 2017; 240:717-724. [PMID: 28946334 DOI: 10.1016/j.foodchem.2017.08.008] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 07/14/2017] [Accepted: 08/01/2017] [Indexed: 10/19/2022]
Abstract
The present work aims to systematically demonstrate the authenticity of honeys with non-extractable proteins for the first time, by means of EA-IRMS and LC-IRMS. Fifty-three pure honeys of various botanical and geographical origins were studied and a criterion on the basis of the stable carbon isotope ratio characterization of total honey and the main sugars was established for pure honeys. Parameters such as δ13C values of total honey and the main sugars were well utilized to identify honeys with non-extractable proteins. Thirty-five honeys from which protein could not be extracted were all identified as adulterated with C-4 sugars or C-3 sugars. The use of isotopic compositions and some systematic differences permit the honeys with non-extractable proteins to be reliably identified. The findings obtained in this work could supplement the AOAC 998.12 C-4 sugar method, with regard to honeys from which protein cannot be extracted.
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Affiliation(s)
- Hao Dong
- School of Food Science and Technology, South China University of Technology, Guangzhou 510640, China
| | - Kaijun Xiao
- School of Food Science and Technology, South China University of Technology, Guangzhou 510640, China.
| | - Yanping Xian
- Guangzhou Quality Supervision and Testing Institute, National Centre for Quality Supervision and Testing of Processed Food (Guangzhou), Guangzhou 511447, China
| | - Yuluan Wu
- Guangzhou Quality Supervision and Testing Institute, National Centre for Quality Supervision and Testing of Processed Food (Guangzhou), Guangzhou 511447, China
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Spiteri M, Rogers KM, Jamin E, Thomas F, Guyader S, Lees M, Rutledge DN. Combination of 1H NMR and chemometrics to discriminate manuka honey from other floral honey types from Oceania. Food Chem 2017; 217:766-772. [DOI: 10.1016/j.foodchem.2016.09.027] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 05/30/2016] [Accepted: 09/05/2016] [Indexed: 11/25/2022]
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14
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Rapid and Reliable HPLC Method for the Simultaneous Determination of Dihydroxyacetone, Methylglyoxal and 5-Hydroxymethylfurfural in Leptospermum Honeys. PLoS One 2016; 11:e0167006. [PMID: 27861622 PMCID: PMC5115846 DOI: 10.1371/journal.pone.0167006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 11/07/2016] [Indexed: 11/29/2022] Open
Abstract
A reliable determination of dihydroxyacetone, methylglyoxal and 5-hydroxymethylfurfural is essential to establishing the commercial value and antimicrobial potential of honeys derived from the Leptospermum species endemic to Australia and New Zealand. We report a robust method for quantitation of all three compounds in a single HPLC run. Honey samples (n = 6) that are derivatized with o-(2,3,4,5,6-Pentafluorobenzyl) hydroxylamine were quantitated against a stable anisole internal standard. Linear regression analysis was performed using calibration standards for each compound (n = 6) and results indicated a high degree of accuracy (R2 = 0.999) for this method. The reliability of some commercial methylglyoxal solutions were found to be questionable. Effective quantitation of methylglyoxal content in honey is critical for researchers and industry, and the use of some commercial standards may bias data. Two accurate methylglyoxal standards are proposed, including a commercial standard and a derivative that can be prepared within the laboratory.
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15
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Dong H, Xiao K, Luo D, Xian Y, Luo H, Guo X, Li C, Zhao M. Adulteration Identification of Commercial Honey with the C-4 Sugar Content of Negative Values by an Elemental Analyzer and Liquid Chromatography Coupled to Isotope Ratio Mass Spectroscopy. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:3258-3265. [PMID: 27064147 DOI: 10.1021/acs.jafc.6b00691] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
According to the AOAC 998.12 method, honey is considered to contain significant C-4 sugars with a C-4 sugar content of >7%, which are naturally identified as the adulteration. However, the authenticity of honey with a C-4 sugar content of <0% calculated by the above method has been rarely investigated. A new procedure to determine δ(13)C values of honey, corresponding extracted protein and individual sugars (sucrose, glucose, and fructose), δ(2)H and δ(18)O values, sucrose content, and reducing sugar content of honey using an elemental analyzer and liquid chromatography coupled to isotope ratio mass spectroscopy, was first developed to demonstrate the authenticity of honey with a C-4 sugar content of <0%. For this purpose, 800 commercial honey samples were analyzed. A quite similar pattern on the pentagonal radar plot (isotopic compositions) between honey with -7 < C-4 sugar content (%) < 0 and 0 < C-4 sugar content (%) < 7 indicated that honey with -7 < C-4 sugar content (%) < 0 could be identified to be free of C-4 sugars as well. A very strong correlation is also observed between δ(13)C honey values and δ(13)C protein values of both honey groups. For the δ(18)O value, the C-4 sugar content (%) < -7 group has lower (p < 0.05) values (16.30‰) compared to other honey, which could be a useful parameter for adulterated honey with a C-4 sugar content (%) < -7. The use of isotopic compositions and some systematic differences permits the honey with a C-4 sugar content of <0% to be reliably detected. The developed procedure in this study first and successfully provided favorable evidence in authenticity identification of honey with a C-4 sugar content of <0%.
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Affiliation(s)
- Hao Dong
- Guangzhou Quality Supervision and Testing Institute, National Centre for Quality Supervision and Testing of Processed Food (Guangzhou) , Guangzhou, Guangdong 511400, People's Republic of China
- School of Food Science and Technology, South China University of Technology , Guangzhou, Guangdong 510640, People's Republic of China
| | | | - Donghui Luo
- Guangzhou Quality Supervision and Testing Institute, National Centre for Quality Supervision and Testing of Processed Food (Guangzhou) , Guangzhou, Guangdong 511400, People's Republic of China
- School of Food Science and Technology, South China University of Technology , Guangzhou, Guangdong 510640, People's Republic of China
- Guangzhou TaiHui Biological Technology Company, Limited , Guangzhou, Guangdong 510640, People's Republic of China
| | - Yanping Xian
- Guangzhou Quality Supervision and Testing Institute, National Centre for Quality Supervision and Testing of Processed Food (Guangzhou) , Guangzhou, Guangdong 511400, People's Republic of China
| | - Haiying Luo
- Guangzhou Quality Supervision and Testing Institute, National Centre for Quality Supervision and Testing of Processed Food (Guangzhou) , Guangzhou, Guangdong 511400, People's Republic of China
| | - Xindong Guo
- Guangzhou Quality Supervision and Testing Institute, National Centre for Quality Supervision and Testing of Processed Food (Guangzhou) , Guangzhou, Guangdong 511400, People's Republic of China
| | - Chao Li
- School of Food Science and Technology, South China University of Technology , Guangzhou, Guangdong 510640, People's Republic of China
| | - Mouming Zhao
- School of Food Science and Technology, South China University of Technology , Guangzhou, Guangdong 510640, People's Republic of China
- Guangzhou TaiHui Biological Technology Company, Limited , Guangzhou, Guangdong 510640, People's Republic of China
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16
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Kato Y, Fujinaka R, Ishisaka A, Nitta Y, Kitamoto N, Takimoto Y. Plausible authentication of manuka honey and related products by measuring leptosperin with methyl syringate. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:6400-6407. [PMID: 24941263 DOI: 10.1021/jf501475h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Manuka honey, obtained from Leptospermum scoparium flowers in New Zealand, has strong antibacterial properties. In this study, plausible authentication of the manuka honey was inspected by measuring leptosperin, methyl syringate 4-O-β-D-gentiobiose, along with methyl syringate. Despite a gradual decrease in methyl syringate content over 30 days at 50 °C, even at moderate 37 °C, leptosperin remained stable. A considerable correlation between nonperoxide antibacterial activity and leptosperin content was observed in 20 certified manuka honey samples. Leptosperin and methyl syringate in manuka honey and related products were analyzed using HPLC connected with mass spectrometry. One noncertified brand displayed significant variations in the leptosperin and methyl syringate contents between two samples obtained from different regions. Therefore, certification is clearly required to protect consumers from disguised and/or low-quality honey. Because leptosperin is stable during storage and specific to manuka honey, its measurement may be applicable for manuka honey authentication.
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Affiliation(s)
- Yoji Kato
- School of Human Science and Environment, and ‡Research Institute for Food and Nutritional Sciences, University of Hyogo , Hyogo, Japan
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17
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Khan F, Hill J, Kaehler S, Allsopp M, van Vuuren S. Antimicrobial properties and isotope investigations of South African honey. J Appl Microbiol 2014; 117:366-79. [DOI: 10.1111/jam.12533] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Revised: 04/11/2014] [Accepted: 04/21/2014] [Indexed: 11/30/2022]
Affiliation(s)
- F. Khan
- Department of Pharmacy and Pharmacology; University of the Witwatersrand; Johannesburg South Africa
| | - J. Hill
- Department of Zoology and Entomology; Rhodes University; Grahamstown South Africa
| | - S. Kaehler
- Department of Botany; Rhodes University; Grahamstown South Africa
| | - M. Allsopp
- Plant Protection Research Institute; Agricultural Research Council; Stellenbosch South Africa
| | - S. van Vuuren
- Department of Pharmacy and Pharmacology; University of the Witwatersrand; Johannesburg South Africa
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Rogers KM, Sim M, Stewart S, Phillips A, Cooper J, Douance C, Pyne R, Rogers P. Investigating C-4 sugar contamination of manuka honey and other New Zealand honey varieties using carbon isotopes. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:2605-2614. [PMID: 24568639 DOI: 10.1021/jf404766f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Carbon isotopes (δ(13)C honey and δ(13)C protein) and apparent C-4 sugar contents of 1023 New Zealand honeys from 15 different floral types were analyzed to investigate which New Zealand honey is prone to failing the AOAC 998.12 C-4 sugar test and evaluate the occurrence of false-positive results. Of the 333 honey samples that exceeded the 7% C-4 sugar threshold, 324 samples of these were New Zealand manuka honey (Leptospermum scoparium, 97.2% of all fails found in the study). Three monofloral honeys (ling, kamahi, and tawari) had nine samples (2.8% of all fails found in the study) with apparent C-4 sugars exceeding 7%. All other floral types analyzed did not display C-4 sugar fails. False-positive results were found to occur for higher activity New Zealand manuka honey with a methylglyoxal content >250 mg/kg or a nonperoxide activity >10+, and for some ling, kamahi and tawari honeys. Recommendations for future interpretation of the AOAC 998.12 C-4 sugar method are proposed.
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Affiliation(s)
- Karyne M Rogers
- National Isotope Centre, GNS Science, 30 Gracefield Road, Lower Hutt 5040, New Zealand
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