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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."

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

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

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

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

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

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

Rowe, A., Eyres, G. T., & Birch, E. J. (2016). Characterisation of volatile organic compounds in New Zealand honey. Proceedings of the New Zealand Institute of Food Science & Technology (NZIFST) Conference. (pp. 37). Retrieved from http://www.nzifst.org.nz/conference.asp

Eyres, G., Gould, B., Ting, V., Leus, M., Richter, T., Silcock, P., & Bremer, P. (2016). Characterisation of New Zealand hop character and the impact of yeast strain on hop derived compounds in beer. Proceedings of the 34th Asia Pacific Convention of the Institute of Brewing and Distilling. Retrieved from http://convention2016.ibdasiapac.com.au/

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.

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.

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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

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

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

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, 9093-9102. doi: 10.1021/acs.jafc.5b03441

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

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

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

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

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

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, 433-444. doi: 10.1002/ffj.3113

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

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.

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

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

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

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

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.

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

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

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.

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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.

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

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Conference Contribution - Published proceedings: Abstract

Rowe, A., Eyres, G. T., & Birch, E. J. (2016). Characterisation of volatile organic compounds in New Zealand honey. Proceedings of the New Zealand Institute of Food Science & Technology (NZIFST) Conference. (pp. 37). Retrieved from http://www.nzifst.org.nz/conference.asp

Eyres, G., Gould, B., Ting, V., Leus, M., Richter, T., Silcock, P., & Bremer, P. (2016). Characterisation of New Zealand hop character and the impact of yeast strain on hop derived compounds in beer. Proceedings of the 34th Asia Pacific Convention of the Institute of Brewing and Distilling. Retrieved from http://convention2016.ibdasiapac.com.au/

Zolfaghari, Z. S., Birch, J., & Eyres, G. (2016). Differentiation of New Zealand kanuka and manuka honey using rheometric parameters. Proceedings of the New Zealand Institute of Food Science & Technology (NZIFST) Conference. (pp. 49). Retrieved from http://www.nzifst.org.nz/conference.asp

Jones, J., Ripberger, G., Eyres, G., & Archer, R. (2016). Adding value by culinary smoking. Proceedings of the New Zealand Institute of Food Science & Technology (NZIFST) Conference. (pp. 22). Retrieved from http://www.nzifst.org.nz/conference.asp

Richter, T., Eyres, G., Silcock, P., & Bremer, P. (2016). Identification of hop-derived aroma compounds in beer from Nelson Sauvin hops. Proceedings of the 34th Asia Pacific Convention of The Institute of Brewing and Distilling. Retrieved from http://convention2016.ibdasiapac.com.au/

Scrimgeour, J., Eyres, G., Richter, T., Silcock, P., & Bremer, P. (2016). Impact of fermentation parameters on hop derived aroma compounds in beer. Proceedings of the New Zealand Institute of Food Science & Technology (NZIFST) Conference. (pp. 43). Retrieved from http://www.nzifst.org.nz/conference.asp

Bierlin, U., Bremer, P., & Eyres, G. (2016). Antibacterial powers of five New Zealand hop varieties. Proceedings of the New Zealand Institute of Food Science & Technology (NZIFST) Conference. (pp. 47-48). Retrieved from http://www.nzifst.org.nz/conference.asp

Dufour, J.-P., Delahunty, C., & Eyres, G. T. (2006). Gas chromatography-olfactometry: Review of methodologies and best practices. In T. Sandra & P. Sandra (Eds.), Proceedings of the 29th International Symposium on Capillary Chromatography & 3rd GCxGC Symposium. [CD-ROM] Kortrijk, Belgium: IOPMS.

Eyres, G. T., Dufour, J.-P., & Marriott, P. J. (2006). GC-olfactometry and GCxGC-TOFMS: A powerful combination for the characterisation of essential oils. In T. Sandra & P. Sandra (Eds.), Proceedings of the 29th International Symposium on Capillary Chromatography & 3rd GCxGC Symposium. [CD-ROM] Kortrijk, Belgium: IOPMS.

Eyres, G., Dufour, J.-P., Hallifax, G., Sotheeswaran, S., & Marriott, P. J. (2005). Identification of character-impact odorants in coriander and wild coriander leaves. Proceedings of the New Zealand Institute of Food Science and Technology Annual Conference. (pp. 41).

Eyres, G., Dufour, J.-P., & Marriott, P. J. (2005). Identification of character-impact odorants in essential oils. Proceedings of the New Zealand Institute of Food Science and Technology Annual Conference. (pp. 38).

Lim, M. H., Heenan, S., & Eyres, G. (2005). Extending shelf life of marshmallow by process manipulation. Proceedings of the Institute of Food Technologists Annual Meeting. Retrieved from http://ift.confex.com/ift/2005/techprogram/paper_30309.htm

Eyres, G., Dufour, J.-P., Hallifax, G., Sotheeswaran, S., & Marriott, P. (2005). Identification of character impact odorants in coriander and wild coriander leaves using GC-olfactometry and GC x GC-TOFMS. Proceedings of the 11th Weurman Flavour Research Symposium.

Eyres, G., Dufour, J.-P., & Marriott, P. (2004). Characterisation of hop essential oils using comprehensive multidimensional gas chromatography (GC × GC). Proceedings of the NZIFST / DIANZ Joint Conference: Great Science! Great Food! (pp. 28).

Eyres, G., & Lim, M. (2001). Foam characteristics and the stability of marshmallows. New Zealand Institute of Food Technologists Annual Conference Proceeding. 33. Dunedin.

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Conference Contribution - Poster Presentation (not in published proceedings)

Gould, B., Eyres, G. T., & Bremer, P. J. (2015, June-July). Impact of yeast and hops on flavour and aroma generation in beer. Poster session presented at the New Zealand Institute of Food Science & Technology (NZIFST) 50th Anniversary Conference, Palmerston North, New Zealand.

Zolfaghari, Z., Eyres, G., & Birch, J. (2015, June-July). Determination of thermal behaviour of New Zealand unifloral honeys using DSC and TGA. Poster session presented at the New Zealand Institute of Food Science & Technology (NZIFST) 50th Anniversary Conference, Palmerston North, New Zealand.

Roberts, M., Dufour, J.-P., Lewis, A. C., & Eyres, G. (2004, July). The comprehensive analysis of hop oil using two-dimensional gas chromatography combined with time-of-flight mass spectrometry. Poster session presented at the World Brewing Congress, San Diego, USA.

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Conference Contribution - Verbal presentation and other Conference outputs

Eyres, G. T., & Silcock, P. (2015, June-July). Utilising volatile aroma analysis for understanding flavour perception. Verbal presentation at the New Zealand Institute of Food Science & Technology (NZIFST) 50th Anniversary Conference, Palmerston North, New Zealand.

Eyres, G. T., Marriott, P. J., Leus, M., & Lysaght, B. (2014, September). Characterisation of character impact aroma compounds in hop essential oils. Verbal presentation at the 14th Weurman Flavour Research Symposium, Cambridge, UK.

Eyres, G. (2014, July). Opportunities for understanding dynamic flavour perception. Verbal presentation at the New Zealand Institute of Food Science & Technology (NZIFST) Conference: Challenges into Opportunities, Christchurch, New Zealand.

More publications...