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Dr Graham Eyres

Senior Lecturer

PhD (Otago), BSc (Hons) (Otago)

Graham Eyres

Contact

Tel 64 3 479 7661 Ext 7661
Email graham.eyres@otago.ac.nz
Location CSB 108

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About

The goal of Graham’s research is to investigate and understand the physico-chemical factors that drive sensory perception of flavour. His interests are in taste and aroma compounds and their effect on sensory perception, dynamic flavour release, hop aroma in beer, fermentation science, flavour chemistry, and analytical flavour techniques.

His professional specialities are in flavour science / chemical analysis using GC/MS, GC-olfactometry, PTR-MS and sensory evaluation and perception.

His current research focuses on how flavour compounds interact within a food matrix, the effect of food composition and structure on the dynamic release of taste and aroma compounds and the influence on overall sensory perception of flavour. He is also interested in the interaction of sensory modalities, such as the cross-modal interactions between taste and aroma, and their effect on flavour perception.

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Teaching

Course Co-ordinator

Contributor to

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Research

Research interests

  • Identification of aroma compounds in complex food samples and essential oils
  • Oral breakdown of food during mastication and impact on flavour release and sensory perception.
  • Dynamic flavour release and perception during consumption
  • Sensory interactions between taste and aroma and the effect on overall flavour perception
  • Hop aroma compounds, flavour generation during fermentation, and the impact on beer flavour

Research projects

  • Identification of aroma compounds in complex food samples and essential oils. 
  • Using gas chromatography-olfactometry to identify odour-active compounds and to identify the compounds responsible using gas chromaotography and mass spectrometry. 
  • Correlation of instrumental methods of analysis to sensory perception.
  • Oral breakdown of food during mastication, dynamic flavour release and impact on sensory perception. 
  • Perception of food during eating has a temporal dimension related to the breakdown of food during chewing. 
  • Food composition and structure affect time-intensity perception and perceived quality. 
  • Measurement of dynamic flavour release during consumption using proton transfer reaction mass spectrometry (PTR-MS) 
  • Application for reformulation of products to achieve healthier foods (e.g. lower fat)
  • Sensory interactions between taste and aroma and the effect on overall flavour perception. 
  • Understanding integration of different taste and aroma stimuli and the integrated perception of flavour.
  • Hop aroma compounds, flavour generation during fermentation, and the impact on beer flavour. 
  • Identify odour-active compounds in hops, focusing on compounds responsible for unique characters of New Zealand hop varieties 
  • Investigate flavour generation by yeast during fermentation and the impact on beer flavour. 
  • Investigate the fate of hop aroma compounds during fermentation and the compounds responsible for hop derived flavour in beer.

Postgraduate supervision

Current students

Rajkumar Nandakumar (PhD), "Understanding the effect of pulsed electric field treatment on secondary metabolite production in Allium cepa L. suspension cultures."

Adam Rowe (MSc thesis), "Characterisation of Volatile Organic Compounds in New Zealand Honey."

Andrea Warburton (PhD), "The impact of sensory interactions on flavour of sourdough bread"

Previous Students

Tobias Richter (PhD), "Hope aroma in beer - changes in flavour profile associated with different yeast strains."

Zahra Zolfaghari (PhD), "Characterization of unifloral honeys based on volatile compounds, physicochemical properties and bioactivity."

Sung-Tong Chin (PhD Monash University, Melbourne, Australia). "Hyphenated techniques in multidimensional gas chromatography for analysis of wine aroma and related odorants."

Bridget Lysaght (Hons 2015), "Characterisation of aroma compounds in selected New Zealand hop (Humulus lupulus) varieties."

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Publications

Adadi, P., Harris, A., Bremer, P., Silcock, P., Ganley, A. R. D., Jeffs, A. G., & Eyres, G. T. (2021). The effect of sound frequency and intensity on yeast growth, fermentation performance and volatile composition of beer. Molecules, 26, 7239. doi: 10.3390/molecules26237239

Pavan, E., Ye, Y., Eyres, G. T., Guerrero, L., Reis, M. G., Silcock, P., … Realini, C. E. (2021). Relationships among consumer liking, lipid and volatile compounds from New Zealand commercial lamb loins. Foods, 10(5). doi: 10.3390/foods10051143

Purdy, V., Kebede, B., Beatson, R., Templeton, K., Silcock, P., & Eyres, G. T. (2021). Differences in New Zealand hop cultivars based on their unique volatile compounds: An integrated fingerprinting and chemometrics approach. Foods, 10(2), 414. doi: 10.3390/foods10020414

High, R., Eyres, G. T., Bremer, P., & Kebede, B. (2021). Characterization of blue cheese volatiles using fingerprinting, self-organizing maps, and entropy-based feature selection. Food Chemistry, 347, 128955. doi: 10.1016/j.foodchem.2020.128955

Ye, Y., Eyres, G. T., Reis, M. G., Schreurs, N. M., Silcock, P., Agnew, M. P., … Realini, C. E. (2020). Fatty acid composition and volatile profile of M. longissimus thoracis from commercial lambs reared in different forage systems. Foods, 9, 1885. doi: 10.3390/foods9121885

Loi, C. C., Eyres, G. T., & Birch, E. J. (2018). Protein-stabilised emulsions. In G. Smithers (Ed.), Reference module in food science. Elsevier. doi: 10.1016/B978-0-08-100596-5.22490-6

Chapter in Book - Research

Chin, S.-T., Eyres, G. T., & Marriott, P. J. (2017). Gas chromatography: Mass spectrometry in odorant analysis. In A. Buettner (Ed.), Springer handbook of odor. (pp. 343-353). Cham, Switzerland: Springer. doi: 10.1007/978-3-319-26932-0_17

Chapter in Book - Research

Eyres, G., & Dufour, J.-P. (2009). Hop essential oil: Analysis, chemical composition and odor characteristics. In V. R. Preedy (Ed.), Beer in health and disease prevention. (pp. 239-254). Burlington, MA: Elsevier.

Chapter in Book - Research

Eyres, G., Dufour, J.-P., Hallifax, G., Sotheeswaran, S., & Marriott, P. J. (2006). Identification of character-impact odorants in coriander and wild coriander leaves using GC-olfactometry and GC x GC-TOFMS. In W. L. P. Bredie & M. A. Petersen (Eds.), Flavour science: Recent advances and trends. (pp. 197-200). Amsterdam, The Netherlands: Elsevier.

Chapter in Book - Research

Adadi, P., Harris, A., Bremer, P., Silcock, P., Ganley, A. R. D., Jeffs, A. G., & Eyres, G. T. (2021). The effect of sound frequency and intensity on yeast growth, fermentation performance and volatile composition of beer. Molecules, 26, 7239. doi: 10.3390/molecules26237239

Journal - Research Article

High, R., Eyres, G. T., Bremer, P., & Kebede, B. (2021). Characterization of blue cheese volatiles using fingerprinting, self-organizing maps, and entropy-based feature selection. Food Chemistry, 347, 128955. doi: 10.1016/j.foodchem.2020.128955

Journal - Research Article

Pavan, E., Ye, Y., Eyres, G. T., Guerrero, L., Reis, M. G., Silcock, P., … Realini, C. E. (2021). Relationships among consumer liking, lipid and volatile compounds from New Zealand commercial lamb loins. Foods, 10(5). doi: 10.3390/foods10051143

Journal - Research Article

Purdy, V., Kebede, B., Beatson, R., Templeton, K., Silcock, P., & Eyres, G. T. (2021). Differences in New Zealand hop cultivars based on their unique volatile compounds: An integrated fingerprinting and chemometrics approach. Foods, 10(2), 414. doi: 10.3390/foods10020414

Journal - Research Article

Kebede, B., Ting, V., Eyres, G., & Oey, I. (2020). Volatile changes during storage of shelf stable apple juice: Integrating GC-MS fingerprinting and chemometrics. Foods, 9(2), 165. doi: 10.3390/foods9020165

Journal - Research Article

Loi, C. C., Eyres, G. T., Silcock, P., & Birch, E. J. (2020). Application of a novel instantized glycerol monooleate ingredient in a protein-stabilized oil-in-water emulsion. Foods, 9(9), 1237. doi: 10.3390/foods9091237

Journal - Research Article

Loi, C. C., Eyres, G. T., Silcock, P., & Birch, E. J. (2020). Preparation and characterisation of a novel emulsifier system based on glycerol monooleate by spray-drying. Journal of Food Engineering, 285, 110100. doi: 10.1016/j.jfoodeng.2020.110100

Journal - Research Article

Ye, Y., Eyres, G. T., Reis, M. G., Schreurs, N. M., Silcock, P., Agnew, M. P., … Realini, C. E. (2020). Fatty acid composition and volatile profile of M. longissimus thoracis from commercial lambs reared in different forage systems. Foods, 9, 1885. doi: 10.3390/foods9121885

Journal - Research Article

Zhang, Y., Silcock, P., Jones, J. R., & Eyres, G. T. (2020). Changes in wood smoke volatile composition by manipulating the smoke generation conditions. Journal of Analytical & Applied Pyrolysis, 148, 104769. doi: 10.1016/j.jaap.2019.104769

Journal - Research Article

Chiang, J. H., Eyres, G. T., Silcock, P. J., Hardacre, A. K., & Parker, M. E. (2019). Changes in the physicochemical properties and flavour compounds of beef bone hydrolysates after Maillard reaction. Food Research International, 123, 642-649. doi: 10.1016/j.foodres.2019.05.024

Journal - Research Article

High, R., Bremer, P., Kebede, B., & Eyres, G. T. (2019). Comparison of four extraction techniques for the evaluation of volatile compounds in spray-dried New Zealand sheep milk. Molecules, 24(10), 1917. doi: 10.3390/molecules24101917

Journal - Research Article

Loi, C. C., Eyres, G. T., & Birch, E. J. (2019). Effect of milk protein composition on physicochemical properties, creaming stability and volatile profile of a protein-stabilised oil-in-water emulsion. Food Research International, 120, 83-91. doi: 10.1016/j.foodres.2019.02.026

Journal - Research Article

Loi, C. C., Eyres, G. T., & Birch, E. J. (2019). Effect of mono- and diglycerides on physical properties and stability of a protein-stabilised oil-in-water emulsion. Journal of Food Engineering, 240, 56-64. doi: 10.1016/j.jfoodeng.2018.07.016

Journal - Research Article

Tantamacharik, T., Leong, S. Y., Leus, M. J., Eyres, G. T., Burritt, D. J., & Oey, I. (2019). Structural changes induced by pulsed electric fields increase the concentration of volatiles released in red onion (Allium cepa L. var. Red Pearl) bulbs. Foods, 8(9), 368. doi: 10.3390/foods8090368

Journal - Research Article

Ye, Y., Schreurs, N. M., Johnson, P. L., Corner-Thomas, R. A., Agnew, M. P., Silcock, P., Eyres, G. T., … Realini, C. E. (2019). Carcass characteristics and meat quality of commercial lambs reared in different forage systems. Livestock Science, 232, 103908. doi: 10.1016/j.livsci.2019.103908

Journal - Research Article

Haddadian, Z., Eyres, G. T., Bremer, P., & Everett, D. W. (2018). Polar lipid composition of the milk fat globule membrane in buttermilk made using various cream churning conditions or isolated from commercial samples. International Dairy Journal, 81, 138-142. doi: 10.1016/j.idairyj.2018.01.012

Journal - Research Article

Kebede, B., Lee, P. Y., Leong, S. Y., Kethireddy, V., Ma, Q., Aganovic, K., Eyres, G. T., … Oey, I. (2018). A chemometrics approach comparing volatile changes during the shelf life of apple juice processed by pulsed electric fields, high pressure and thermal pasteurization. Foods, 7(10), 169. doi: 10.3390/foods7100169

Journal - Research Article

Liu, T., Burritt, D. J., Eyres, G. T., & Oey, I. (2018). Pulsed electric field processing reduces the oxalate content of oca (Oxalis tuberosa) tubers while retaining starch grains and the general structural integrity of tubers. Food Chemistry, 245, 890-898. doi: 10.1016/j.foodchem.2017.11.085

Journal - Research Article

Nandakumar, R., Eyres, G. T., Burritt, D. J., Kebede, B., Leus, M., & Oey, I. (2018). Impact of pulsed electric fields on the volatile compounds produced in whole onions (Allium cepa and Allium fistulosum). Foods, 7(11), 183. doi: 10.3390/foods7110183

Journal - Research Article

Richter, T., Silcock, P., Algarra, A., Eyres, G. T., Capozzi, V., Bremer, P., & Biasioli, F. (2018). Evaluation of PTR-ToF-MS as a tool to track the behavior of hop-derived compounds during the fermentation of beer. Food Research International, 111, 582-589. doi: 10.1016/j.foodres.2018.05.056

Journal - Research Article

Haddadian, Z., Eyres, G. T., Carne, A., Everett, D. W., & Bremer, P. (2017). Impact of different milk fat globule membrane preparations on protein composition, xanthine oxidase activity, and redox potential. International Dairy Journal, 64, 14-21. doi: 10.1016/j.idairyj.2016.09.006

Journal - Research Article

Liu, T., Dodds, E., Leong, S. Y., Eyres, G. T., Burritt, D. J., & Oey, I. (2017). Effect of pulsed electric fields on the structure and frying quality of “kumara” sweet potato tubers. Innovative Food Science & Emerging Technologies, 39, 197-208. doi: 10.1016/j.ifset.2016.12.010

Journal - Research Article

Richter, T. M., Eyres, G. T., Silcock, P., & Bremer, P. J. (2017). Comparison of four extraction methods for analysis of volatile hop-derived aroma compounds in beer. Journal of Separation Science, 40(22), 4366-4376. doi: 10.1002/jssc.201700676

Journal - Research Article

Haddadian, Z., Bremer, P., Eyres, G. T., Carne, A., & Everett, D. W. (2016). The impact of cream churning conditions on xanthine oxidase activity and oxidation-reduction potential in model emulsion systems. International Dairy Journal, 60, 55-61. doi: 10.1016/j.idairyj.2016.01.017

Journal - Research Article

Chin, S.-T., Eyres, G. T., & Marriott, P. J. (2015). Application of integrated comprehensive/multidimensional gas chromatography with mass spectrometry and olfactometry for aroma analysis in wine and coffee. Food Chemistry, 185, 355-361. doi: 10.1016/j.foodchem.2015.04.003

Journal - Research Article

Frank, D., Eyres, G. T., Piyasiri, U., Cochet-Broch, M., Delahunty, C. M., Lundin, L., & Appelqvist, I. M. (2015). Effects of agar gel strength and fat on oral breakdown, volatile release, and sensory perception using in vivo and in vitro systems. Journal of Agricultural & Food Chemistry, 63(41), 9093-9102. doi: 10.1021/acs.jafc.5b03441

Journal - Research Article

Harrison, S. M., Cleary, P. W., Eyres, G., Sinnott, M. D., & Lundin, L. (2014). Challenges in computational modelling of food breakdown and flavour release. Food & Function, 5(11), 2792-2805. doi: 10.1039/c4fo00786g

Journal - Research Article

Harrison, S., Eyres, G., Cleary, P., Sinnott, M. D., Delahunty, C., & Lundin, L. (2014). Computational modeling of feed oral breakdown using smoothed particle hydrodynamics. Journal of Texture Studies, 45, 97-109. doi: 10.1111/jtxs.12062

Journal - Research Article

Chin, S.-T., Eyres, G. T., & Marriott, P. J. (2012). Cumulative solid phase microextraction sampling for gas chromatography-olfactometry of Shiraz wine. Journal of Chromatography A, 1255, 221-227. doi: 10.1016/j.chroma.2012.03.084

Journal - Research Article

Chin, S.-T., Eyres, G. T., & Marriott, P. J. (2012). System design for integrated comprehensive and multidimensional gas chromatography with mass spectrometry and olfactometry. Analytical Chemistry, 84, 9154-9162. doi: 10.1021/ac301847y

Journal - Research Article

Frank, D. C., Eyres, G. T., Piyasiri, U., & Delahunty, C. M. (2012). Effect of food matrix structure and composition on aroma release during oral processing using in vivo monitoring. Flavour & Fragrance Journal, 27(4), 433-444. doi: 10.1002/ffj.3113

Journal - Research Article

Chin, S.-T., Eyres, G. T., & Marriott, P. J. (2011). Identification of potent odourants in wine and brewed coffee using gas chromatography-olfactometry and comprehensive two-dimensional gas chromatography. Journal of Chromatography A, 1218, 7487-7498. doi: 10.1016/j.chroma.2011.06.039

Journal - Research Article

Overington, A., Eyres, G. T., Delahunty, C. M., Silcock, P., Niimi, J., Holland, R., & Coolbear, T. (2010). Flavour release and perception in cheese bases. Australian Journal of Dairy Technology, 65(3), 162-164.

Journal - Research Article

Marriott, P. J., Eyres, G. T., & Dufour, J.-P. (2009). Emerging opportunities for flavor analysis through hyphenated gas chromatography. Journal of Agricultural & Food Chemistry, 57(21), 9962-9971. doi: 10.1021/jf9013845

Journal - Research Article

Rühle, C., Eyres, G. T., Urban, S., Dufour, J.-P., Morrison, P. D., & Marriott, P. J. (2009). Multiple component isolation in preparative multidimensional gas chromatography with characterisation by mass spectrometry and nuclear magnetic resonance spectroscopy. Journal of Chromatography A, 1216(30), 5740-5747. doi: 10.1016/j.chroma.2009.06.006

Journal - Research Article

Eyres, G. T., Urban, S., Morrison, P. D., & Marriott, P. J. (2008). Application of microscale-preparative multidimensional gas chromatography with nuclear magnetic resonance spectroscopy for identification of pure methylnaphthalenes from crude oils. Journal of Chromatography A, 1215(1-2), 168-176. doi: 10.1016/j.chroma.2008.10.102

Journal - Research Article

Eyres, G. T., Urban, S., Morrison, P. D., Dufour, J.-P., & Marriott, P. J. (2008). Method for small-molecule discovery based on microscale-preparative multidimensional gas chromatography isolation with nuclear magnetic resonance spectroscopy. Analytical Chemistry, 80(16), 6293-6299. doi: 10.1021/ac8007847

Journal - Research Article

Eyres, G. T., Marriott, P. J., & Dufour, J.-P. (2007). Comparison of odor-active compounds in the spicy fraction of hop (Humulus lupulus L.) essential oil from four different varieties. Journal of Agricultural & Food Chemistry, 55, 6252-6261.

Journal - Research Article

Eyres, G., Marriott, P. J., & Dufour, J.-P. (2007). The combination of gas chromatography-olfactometry and multidimensional gas chromatography for the characterisation of essential oils. Journal of Chromatography A, 1150, 70-77. doi: 10.1016/j.chroma.2006.07.019

Journal - Research Article

Delahunty, C. M., Eyres, G., & Dufour, J.-P. (2006). Gas chromatography-olfactometry. Journal of Separation Science, 29(14), 2107-2125.

Journal - Research Article

Eyres, G., Dufour, J.-P., Hallifax, G., Sotheeswaran, S., & Marriott, P. J. (2005). Identification of character-impact odorants in coriander and wild coriander leaves using gas chromatography-olfactometry (GCO) and comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS). Journal of Separation Science, 28(9), 1061-1074.

Journal - Research Article

Jones, J., Ripberger, G., Eyres, G., Silcock, P., & Archer, R. (2017). Adding value by culinary smoking. Food New Zealand, 17(3), 12-14.

Journal - Professional & Other Non-Research Articles

Zhang, Y., Eyres, G., Silcock, P., & Jones, J. (2019). Development and performance characterization of a lab-scale smoke generator. In B. Guthrie, J. D. Beauchamp, A. Buettner, S. Toth & M. C. Qian (Eds.), ACS Symposium series: Sex, smoke, and spirits: The role of chemistry (Vol. 1321). (pp. 81-92). Washington, USA: ACS Publications. doi: 10.1021/bk-2019-1321.ch007

Conference Contribution - Published proceedings: Full paper

Eyres, G. T., Marriott, P. J., Leus, M., & Lysaght, B. (2015). Characterisation of impact aroma compounds in hop essential oils. In A. J. Taylor & D. S. Mottram (Eds.), Flavour Science: Proceedings of the XIV Weurman Flavour Research Symposium. (pp. 19-24). Packington, UK: Context Products. [Full Paper]

Conference Contribution - Published proceedings: Full paper

Marriott, P. J., Chin, S. T., & Eyres, G. T. (2012). Exploring comprehensive two-dimensional gas chromatography approaches for identification of potent odorants in wine. In P. Darriet, L. Geny, A. Lonvaud, P. Lucas, G. de Revei & P.-L. Teissedre (Eds.), Proceedings of the OENO2011: Actes de colloques du 9E Symposium international D'Cenologie de Bordeaux. (pp. 639-644). Paris, France: Dunod. [Full Paper]

Conference Contribution - Published proceedings: Full paper

Eyres, G., Dufour, J.-P., & Marriott, P. J. (2006). The spicy character of hops. Proceedings of the 29th Convention of The Institute of Brewing and Distilling. [CD-ROM] Retrieved from http://www.ibdasiapac.com.au/asia-pacific-activities/convention-proceedings/Papers%20&%20Presentations/Eyres%20Graham%20Paper.pdf

Conference Contribution - Published proceedings: Full paper

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