Graham Eyres, Our people, Department of Food Science, University of Otago, New Zealand

Associate Professor

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

Contact

Tel +64 3 479 7661 Ext 7661
Email graham.eyres@otago.ac.nz
Location Sensory Science Research Centre, 270 Leith Walk, Room 108

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About

Associate Professor Graham Eyres teaches and researches food chemistry, flavour science and brewing/fermentation. The objective of his research is to understand the factors that influence the sensory perception of flavour in foods by investigating the interactions between food, food processing, flavour chemistry and sensory science using advanced analytical methods.

Graham’s flavour expertise is applied in a range of projects including including (1) the impact of food processing on food quality, (2) impact of ingredients and fermentation on beer flavour and quality, (3) analysis of volatiles in exhaled breath as a non-invasive measure of metabolism and health status, and (4) analysis of volatiles in vaping e‑liquids and aerosols.

Graham is a professional member of the New Zealand Institute of Food Science and Technology (NZIFST) and active as the Otago-Southland branch secretary. Graham was on the conference organising committee in 2022 and is the conference chair for the 2023 conference in Ōtepoti Dunedin. Graham is Associate Investigator in the Riddet Institute and member of Food Waste Innovation, a University of Otago research theme.

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Teaching

Course Co-ordinator

300 Level co-ordinator
FOSC 201 Food Components, Processing and Functionality
FOSC 301 Food Chemistry, Structure and Function
400 Level Advanced Topics module: Fermented Foods and Beverages
400 Level Advanced Topics module: Brewing
400 Level Advanced Topics module: Flavour Science

Contributor to

FOSC 111 Food in a Changing World
FOSC 201 Food Components, Processing and Functionality
FOSC 202 Food Systems and Quality
FOSC 213 Sensory Science
400 Level Advanced Topics module: Research methods and communication

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Research interests

Identification and analysis of aroma compounds in complex food samples and essential oils using gas chromatography-olfactometry 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.
Measurement of dynamic flavour release during consumption using proton transfer reaction mass spectrometry (PTR-MS)
Hop aroma compounds, flavour generation during fermentation, and the impact on beer flavour.
Generation and control of culinary smoke flavour in foods.
Impact of food processing on food quality and sensory properties in dairy and meat systems.
Evaluation of waste streams from the brewing industry and upcycling opportunities.
Evaluation of the volatile compounds present in vaping liquids and aerosols.

Research projects

2022–2025 MBIE 2022 Endeavour Fund – Smart Ideas. “Recovery of high-value, natural flavour compounds from untapped food processing sources”. PI: G. Eyres, AI: P. Silcock, P. Bremer.
2022–2025 Royal Society Te Apārangi Marsden Fund. “The olfactory cocktail party: How animals and humans segregate mixed odours (21-UOO-039).” Co-PI: P. Szyszka, T. Edwards. AI: G. Eyres, M. Peng, N. Hall.
2021–2023 Health Research Council (HRC) Explorer Grant, “Designing better methodologies to enable robust risk assessment of vaping” (21/731). G. Eyres and P. Silcock.
2021 University of Otago, Food Waste Innovation Theme Seed Research Grant, “Evaluation of brewery waste streams to assess potential for by-product utilization”. PI: G. Eyres, P. Bremer and P. Silcock.
2021. Royal Society Catalyst Seeding General. “Using fermentation to create flavour for plant based analogue products” (21-UOO-004-CSG). PI: Pat Silcock, AI: G. Eyres, P. Bremer, F. Biasioli, V. Capozzi, M. Tufariello.
2019–2023 Fondazione Edmund Mach (FEM), Istituto Agrario San Michele All'Adige, Italy. “Supporting HOP science and technology by high-throughput volatile compound analysis: Understanding changes during fermentation – HOVOC”. Silcock, P, Bremer, P. and Eyres, G.
2017–2021. MBIE 2017 Endeavour Fund – Smart Ideas. “World Beating Beers: Advances in fermentation using underwater sound”. PI: A. Jeffs (University of Auckland). AI: G. Eyres, P. Silcock, A. Ganley, S. Villas-Boas.

Postgraduate supervision

Supervision topics

My research projects and interests are in the following areas. Please contact me for a list of projects.

Flavour science, aroma chemistry and sensory perception.
Analysis of volatile compounds in foods and essential oils.
Hops, flavour generation during fermentation, and the impact on beer flavour.
Evaluation of waste streams from the brewing industry and upcycling opportunities.

Current students

Dhirendra Gehlot (PhD), “Olfactory cocktail party: How human segregate mixture of odours”. Peng, M., Eyres, G., Szyszka, P. [Marsden Funded Scholarship]
Emily Fanning (PhD), “Linking quality to geographical traceability”. Kebede, B., Eyres, G., Frew, R.
Rebecca Roberts (PhD), “Understanding hop flavour in beer using high throughput volatile compound analysis”. Eyres, G., Silcock, P., Bremer, P., Biasioli, F. [UoO Doctoral Scholarship + external funding]
Parise Adadi (PhD), “Effect of sound on fermentation and flavour beer”. Eyres, G., Silcock, P., Bremer, P., Jeffs, A. [UoO Doctoral Scholarship + MBIE Smart Idea fuding]
Chao (Rebecca) Yang (PhD), “Smoke flavour of food as a function of smoke generation parameters and smokehouse conditions”. [MBIE Project funding; FIET Program]
Nadeem Caco (PhD, Massey University), “Understanding and fine tuning the parameters that lead to desirable smoke aromas in culinary smoking”. [MBIE Project funding; FIET Program]

Previous students

Caleb Robinson (PhD; 2022). “Whole grains, Fibre and Health: Carbohydrate digestibility and the microbiome”. Eyres, G., Te Morenga, L., Perry, T., Haszard, J., Mann, J. [Riddet Institute funded PhD scholarship]
Andrea Warburton (PhD, 2021). “The Impact of Sensory Interactions on Flavour of Sourdough Bread”. Eyres, G., Silcock, P. [UoO Doctoral Scholarship]
Ryan High (PhD; 2021). “Evaluation of sheep milk flavour development using an integrated Chemometric and kinetics approach”. Bremer, P., Eyres, G., Kebede, B. [UoO Doctoral Scholarship]
Victoria Purdy (PhD; 2021). “Identifying unique flavour compounds in New Zealand hops to facilitate targeted breeding”. Eyres, G., Kebede, B., Silcock, P. [UoO Doctoral Scholarship].
Yuanyang Zhang (PhD; 2020). “Characterisation of volatile compounds in Manuka smoke”. Eyres, G., Silcock, P., Jones, J.R. [MBIE Project funding; FIET Program]
Marcus Loi (PhD; 2020). “Emulsifier technology to enhance emulsion stability in milk coffee beverages”. Eyres, G., Silcock, P. [UoO Doctoral Scholarship]
Tobias Richter (PhD; 2018), “Hop Aroma in Beer: the effect of yeast strain and fermentation conditions”. Bremer, P., Eyres, G., Silcock, P.
Rajkumar Nandakumar (PhD; 2018), “Understanding the impact of Pulsed Electric Field (PEF) processing on onion bulbs”. Oey, I., Burritt, D., Eyres, G. [UoO Doctoral Scholarship]
Zahra Haddadian (PhD; 2017). “Milkfat globule membrane and functionality in cheese”. Bremer, P., Eyres, G. [Riddet Institute funded PhD scholarship]
Zahra Zolfaghari (PhD; 2017), “Characterization and classification of New Zealand unifloral honeys”. Birch, J., Eyres, G. [UoO Doctoral Scholarship]

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Publications

Kumar, A., Warburton, A., Silcock, P., Bremer, P. J., & Eyres, G. T. (2023). Yeast strain influences the hop-derived sensory properties and volatile composition of beer. Foods, 12, 1064. doi: 10.3390/foods12051064

Benitez, R., Harris, A., Mansfield, E., Silcock, P., Eyres, G., Villas-Bôas, S. G., … Ganley, A. R. D. (2023). Direct liquid transmission of sound has little impact on fermentation performance in Saccharomyces cerevisiae. PLoS ONE, 18(2), e0281762. doi: 10.1371/journal.pone.0281762

Roberts, R., Biasioli, F., Khomenko, I., Eyres, G., Bremer, P., & Silcock, P. (2022). Understanding the generation of volatile organic compounds by yeast during beer fermentation. Proceedings of the 7th MS Food Day. (pp. 119-121). Retrieved from https://www.spettrometriadimassa.it/congressi.html

Warburton, A., Silcock, P., & Eyres, G. T. (2022). Impact of sourdough culture on the volatile compounds in wholemeal sourdough bread. Food Research International, 161, 111885. doi: 10.1016/j.foodres.2022.111885

Hutchings, S. C., Guerrero, L., Smeets, L., Eyres, G. T., Silcock, P., Pavan, E., & Realini, C. E. (2022). Cross-cultural differences in the perception of lamb between New Zealand and Chinese consumers in New Zealand. Foods, 11, 2045. doi: 10.3390/foods11142045

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

Journal - Research Article

High, R., Kebede, B., Eyres, G., & Bremer, P. (2022). Modelling the non-linear development of Shenley Station blue cheese volatiles during ripening using untargeted volatile fingerprinting and self-organizing maps. Food Chemistry Advances. Advance online publication. doi: 10.1016/j.focha.2022.100047

Journal - Research Article

Pavan, E., Subbaraj, A. K., Eyres, G. T., Silcock, P., & Realini, C. E. (2022). Association of metabolomic and lipidomic data with Chinese and New Zealand consumer clusters showing preferential likings for lamb meat from three production systems. Food Research International, 158, 111504. doi: 10.1016/j.foodres.2022.111504

Journal - Research Article

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

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