Matís Staff

Guðjón Þorkelsson

Strategy & Stakeholders

Group: Value chain

Phone: +354 4225044/8585044

Email: gudjon.thorkelsson@matis.is

Focus Areas:

Product Development, Processing, Peptide, Protein, Project Management, Food Processing

Bibliography / Publications

Dissertations / Thesis work

Guðjón Þorkelsson: The Viscometric Monitoring of Starches. M .. Sc. Thesis. University of Leeds 1981

Ritrýndar greinar / Articles in peer-reviewed journals

2013:

G. Reza Shaviklo, Gudjon Thorkelsson, Kolbrun Sveinsdottir, Fatemeh Pourreza. Studies on processing, consumer survey and storage stability of a ready-to-reconstitute fish cutlet mix. Journal of Food Science and Technology, 50(5), 900-908. Article 

Halldorsdottir, SM, Kristinsson, HG, Sveinsdottir, H., Þorkelsson, G., Hamaguchi, PY 2013. The effect of natural antioxidants on haemoglobin-mediated lipid oxidation during enzymatic hydrolysis of cod protein. Food Chemistry. 141(2), 914-919. Article

Nguyen, MV, Arason, S., Thorkelsson, G., Gudmundsdottir, A., Thorarinsdottir, KA, Vu, BN 2013. Effects of added phosphates on lipid stability during salt curing and rehydration of cod (Gadus morhua). Journal of the American Oil Chemists' Society. 90(3), 317-326.  Article 

2012:

Shaviklo, GR, Thorkelsson, G., Arason, S., Sveinsdottir, K. 2012. Characteristics of freeze-dried fish protein isolated from saithe (Pollachius virens). Journal of Food Science and Technology. 49(3), 309-318.  Article

Nguyen, MV, Jonsson, JO, Thorkelsson, G., Arason, S., Gudmundsdottir, A., Thorarinsdottir, KA 2012. Quantitative and qualitative changes in added phosphates in cod (Gadus morhua) during salting, storage and rehydration. LWT-Food Science and Technology. 47, 126-132. Article

Shaviklo, AR, Thorkelsson, G., Arason, S. 2012. Quality changes of fresh and frozen protein solutions extracted from Atlantic Cod (Gadus morhua) trim as affected by salt, cryoprotectants and storage time. Turkish Journal of Aquatic and Fisheries Sciences. 12, 41-51. Article

Minh Van Nguyen, Kristin Anna Thorarinsdottir, Gudjon Thorkelsson, Agusta Gudmundsdottir, Sigurjon Arason. 2012. Influences of potassium ferrocyanide on lipid oxidation of salted cod (Gadus morhua) during processing, storage and rehydration. Food Chemistry. 131(4), 1322-1331. Article

2011:

Gholam Reza Shaviklo, Adalheidur Olafsdottir, Kolbrun Sveinsdottir, Gudjon Thorkelsson, Fereidoon Rafipour. 2011. Quality characteristics and consumer acceptance of a high fish protein puffed corn-fish snack. Journal of Food Science and Technology-Mysore, 48 (6), 668-676. Article 

Sigrún Mjöll Halldórsdóttir, Patricia Y Hamaguchi, Hólmfríður Sveinsdóttir, Hördur G Kristinsson, Arnljótur B Bergsson, Guðjón Thorkelsson. 2011. Properties of hydrolysed saith protein isolates prepared via pH shift process with and without dewatering. LWT - Food Science and Technology. 44 (10), 1999-2004. Article

Arnarson, A., Ólafsdóttir, A., Ramel, A. Martinsdóttir, E., Reykdal, Ó., Þórsdóttir, I., Þorkelsson, G. 2011. Sensory analysis and consumer surveys of fat- and salt-reduced meat products and their use in an energy-reduced diet in overweight individuals. International Journal of Food Sciences and Nutrition. 62(8), 872-880. Article

Nguyen, Minh V., Jonsson, Asbjorn, Thorarinsdottir, Kristin A., Arason, Sigurjon, Thorkelsson, Gudjon. 2011. Effects of different temperatures on storage quality of heavily salted cod (Gadus morhua). International Journal of Food Engineering. 7 (1), Article 3. Article

Gholam Reza Shaviklo, Gudjon Thorkelsson, Kolbrun Sveinsdottir, Fereidon Rafipour. 2011. Chemical properties and sensory quality of ice cream fortified with fish protein. Journal of the Science of Food and Agriculture. 91 (7), 1199-1204. Article

Gholam Reza Shaviklo, Gudjon Thorkelsson, Fereidon Rafipour, Sjofn Sigurgisladottir. 2011. Quality and storage stability of extruded puffed corn-fish snacks during 6-month storage at ambient temperature. Journal of the Science of Food and Agriculture. 91(5), 886-893. Article

Margret Geirsdottir, Hordur G. Kristinsson, Sjofn Sigurgisladottir, Patricia Yuca Hamaguchi, Gudjon Thorkelsson, Ragnar Johannsson, Magnus Mar Kristjansson. 2011. Enzymatic hydrolysis of blue whiting (Micromesistius poutassou); functional and bioactive properties. Journal of Food Science. 76 (1), C14-C20. Article

Van Nguyen, M., Thorarinsdottir, KA, Gudmundsdottir, A., Thorkelsson, G., Arason, S. 2011. The effects of salt concentration on conformational changes in cod (Gadus morhua) proteins during brine salting. Food Chemistry. 125(3) 1013-1019. Article

2010:

Kristin Anna Thorarinsdottir, Sigurjon Arason, Gudjon Thorkelsson, Sjofn Sigurgisladottir, Eva Tornberg. 2010. The effects of pre-salting methods from injection to pickling on the yields of heavily salted cod (Gadus morhua). Journal of Food Science, 75 (8), E544-E551. Article

Gholam Reza Shaviklo, Gudjon Thorkelsson, Sigurjon Arason. 2010. The influence of additives and frozen storage on functional properties and flow behavior of fish protein isolated from haddock (Melanogrammus aeglefinus). Turkish Journal of Fisheries and Aquatic Sciences. 10, 333-340. Article

Minh Van Nguyen, Sigurjon Arason, Kristin Anna Thorarinsdottir, Gudjon Thorkelsson, Agusta Gudmundsdottir. 2010. Influence of salt concentration on the salting kinetics of cod loin (Gadus morhua) during brine salting.  Journal of Food Engineering, 100(2), 225-231. Article

Gholam Reza Shaviklo, Gudjon Thorkelsson, Sigurjon Arason, Hordur G Kristinsson, Kolbrun Sveinsdottir. The influence of additives and drying methods on quality attributes of fish protein powder made from saithe (Pollachius virens). Journal of the Science of Food and Agriculture. 90(12), 2133-2143.  Article 

Laurent Picot, Rozenn Ravallec, Martine Fouchereau-Péron, Laurent Vandanjon, Pascal Jaouen, Maryse Chaplain-Derouiniot, Fabienne Guérard, Aurélie Chabeaud, Yves LeGal, Oscar Martinez Alvarez, Jean-Pascal Bergé, Jean-Marie Piot, Irineu Batista, Carine , Gudjon Thorkelsson, Charles Delannoy, Greta Jakobsen, Inez Johansson, Patrick Bourseau. 2010. Impact of ultrafiltration and nanofiltration of an industrial fish protein hydrolyzate on its bioactive properties (pn / a). Journal of the Science of Food and Agriculture. 90 (11) 1819-1826.  Article 

Tao Wang, Rósa Jónsdóttir, Hördur G. Kristinsson, Gudjon Thorkelsson, Charlotte Jacobsen, Patricia Yuca Hamaguchi, and Gudrun Ólafsdóttir. 2010. Inhibition of haemoglobin-mediated lipid oxidation in washed cod muscle and cod protein isolates by Fucus vesiculosus extract and fractions. Food Chemistry. 123, 321-330.  Article

Gholam Reza Shaviklo, Sigurjon Arason, Gudjon Thorkelsson, Kolbún Sveinsdottir, Emilia Martinsdottir. 2010. Sensory attributes of haddock balls affected by added fish protein isolate and frozen storage. Journal of Sensory Studies. 25(3) 316-331. Article

Van Nguyen, M., Thorarinsdottir, KA, Gudmundsdottir, A., Thorkelsson, G., Arason, S. The effects of salt concentration on conformational changes in cod (Gadus morhua) proteins during brine salting. Food Chemistry. Accepted for Publication September 2010. Article

BOOK CHAPTERS

Sivakumar Raghavan, Hordur G. Kristinsson, Gudjon Thorkelsson, Ragnar Johannsson. 2010. Antioxidant properties of fish protein hydrolysates, chapter 41. In: Handbook of Seafood Quality, Safety and Health Applications. Cesarettin Alasalvar, Kazuo Miyashita, Fereidoon Shahidi, Udaya Wanasundara (Editors). Oxford, Wiley-Blackwell.

2009:

P. Bourseau, L. Vandanjon, P. Jaouen, M. Chaplain-Derouiniot, A. Massé, F. Guérard, A. Chabeaud, M. Fouchereau-Péron, Y. Le Gal, R. Ravallec-Plé, J.- P. Bergé, L. Picot, J.-M. Piot, I. Batista, G. Thorkelsson, C. Delannoy, G. Jakobsen, I. Johansson. 2009. Fractionation of fish protein hydrolysates by ultrafiltration and nanofiltration: impact on peptidic populations. Desalination 244 (1-3), 303–320.  Article  

2007:

Sveinn Margeirsson, Gudmundur R. Jonsson, Sigurjon Arason, Gudjon Thorkelsson, Sjofn Sigurgisladottir, Birgir Hrafnkelsson and Pall Jensson. 2007. Food Engineering Trends - Icelandic View. In: Food Engineering Research Developments. Edited by Terrance P. Klening. Hauppauge NY, Nova Science Publishers Inc. pp. 1-24.

Margrét Geirsdóttir, H. Hlynsdottir, Guðjón Þorkelsson and Sjöfn Sigurgísladóttir. 2007. Solubility and viscosity of herring (Clupea harengus) proteins as affected by freezing and frozen storage. Journal of Food Science, 72 (7): 376-380. Article

C. Sañudo, M. Alfonso, R. San Julián, G. Thorkelsson, T. Valdimarsdottir, D. Zygoyiannis, C. Stamataris, E. Piasentier, C. Mills, P. Berge, E. Dransfield, GR Nute, M. Enserand AV Fisher. 2007. Regional variation in the hedonic evaluation of lamb meat from various production systems by consumers in six European countries. Meat Science, 75 (4): 610-621 Article

Sveinn Margeirsson, Guðmundur R. Jónsson, Sigurjón Arason, Guðjón Þorkelsson. 2007. Processing forecast of cod - Influencing factors on yield, gaping, bruises and nematodes in cod (Gadus Morhua) fillets. Journal of Food Engineering, 80(2):503-508 Article

2006:
L. Picot, S. Bordenave, S. Didelot, I. Fruitier-Arnaudin, F. Sannier, G. Thorkelsson, JP Berge, F. Gue´rard, A. Chabeaud, JM Piot. (2006). Antiproliferative activity of fish protein hydrolysates on human breast cancer cell lines. Process Biochemistry, Volume 41, Issue 5, May 2006, pp 1217-1222. Read the article

A Chabeaud, Vandanjon L, Jaouen P, Bourseau, Delannoy C, Johannsson R, Thorkelsson G and Guerard F. 2006. Evaluation of antioxidant activities in by-product hydrolysates: fractionation and concentration of active molecules using ultra- and nanofiltration membranes. In Seafood Research from fish to dish. Edited by Joop Luten et.al. p 419-426. ISBN-10: 90-8686-005-2. Wageningen Academic Publishers 2006

2005:
Birna Guðbjörnsdóttir, Hjörleifur Einarsson, Guðjón Þorkelsson. (2005). Microbial Adhesion to Processing Lines for Fish Fillets and Cooked Shrimp: Influence of Stainless Steel Surface Finish and Presence of Gram-Negative Bacteria on the Attachment of Listeria monocytogenes. Food Technology and Biotechnology, 43 (1) 55–61. Read the article

L.Picot, S.Bordenave-Juchereau, S.Didelot, QYZhao, L. Murillo, I.Fruitier-Arnaudin, F. Sannier, G. Thorkelsson and JM. Piot. 2005. Research of in vitro anticancer peptides from fish protein hydrolysates. FEBS journal volume 272 supplement 1. July 2005. Abstract B2-036P - page 159.

2004:
B. Gudbjornsdottir, MLSuihko, P.Gustavsson, G.Thorkelsson, S.Salo, AMSjöberg, O. Niclasen, S.Bredholt. 2004. The incidence of Listeria monocytogenes in meat, poultry and seafood plants in the Nordic countries. Food Microbiology 21 (2004) 217-225.

KA Thorarinsdottir, G. Gudmundsdottir, S.Arason, G.Thorkelsson and K. Kristbergsson. 2004. Effects of added salt, phosphates and proteins on the chemical and physiochemical characteristics of frozen cod (Gadus morhua) fillets. Journal of Food Science. Vol.69, No.4, 2004.

2003:
R. Jonsdottir, T. Valdimarsdottir, B. Baldursdottir and G. Thorkelsson. 2003. Influence of Low Fat Fish Meat on Fatty Acid Composition and Sensory Quality of Pork. Journal of Muscle Foods. 14 (1): 51-66.

Berge P, Sanudo C, Sanchez A, Alfonso M, Stamataris C, Thorkelsson G, Piasentier and Fisher A. 2003. Comparison of muscle composition and meat quality traits in various commercial lamb types. Journal of Muscle Foods 14 (4): 281-300.

C. Sañudo, M. Alfonso, A. Sanchez, P. Berge, E. Dransfield, D. Zygoyiannis, C. Stamataris, G. Thorkelsson, T. Valdimarsdottir, E. Piasentier and C. Mills, GRNute and AVFisher. 2003. Meat texture of commercial lambs from different European production systems. Australian Journal of Agricultural Research, 2003,54, 551-560.

2002:
Suihko, M.-L., Gustafsson, P., Niclasen, O., Guðbjörnsdóttir, B., Thorkelsson, G., Salo, S., Sjöberg, A.-M. & Bredholt, S. 2002. Characterization of Listeria monocytogenes isolates from meat, poultry and seafood industries by automated ribotyping and RAPD. Int. J. Food Microbiol. 72: 137-146.

Thorarinsdottir, KA, Arason, S, Thorkelsson, G. (2002). The effects of light salting on physicochemical characteristics of frozen cod fillets (Gadus morhua). Journal of Aquatic Food Product Technology, 11 (3/4) 287-30.

2001:
Alfonso, M., Sanudo, C., Berge, P., Fisher, A., Zygoyiannis D., Thorkelsson G. & Piasantier, E. 2001. Influential factors in sheep quality, acceptability of specific designations. In: Proceedings of a Seminar “Production systems and product quality”. FAO-CIHEAM Network on Sheep and Goats- Subnetwork Production Systems. pp. 19-28.

Hordur G. Kristinsson, Birna Baldursdottir, Rosa Jonsdottir, Thyri Valdimarsdottir, and Gudjon Thorkelsson. 2001. Influence of Feed Composition on Fatty Acid Composition, Unsaturation and Lipid Oxidation of Pig Backfat and Sensory Quality of Pork. Journal of Muscle Foods. 12 (4): 285-300.

Hordur G. Kristinsson, Rosa Jonsdottir, Birna Baldursdottir, Þyri Valdimarsdottir and Gudjon Þorkelsson. 2001 Oxidative stability of pork pepperoni during processing and different packing and storage conditions as influenced by pig feed fat source. Journal of Muscle Foods. 12 (4): 301-315.

2000:
Dransfield, E., Martin, JF, Fisher, A., Nute, GR, Zygiyiannis, D., Stamataris, C., Thorkelsson, G., Valdimarsdottir, T., Piasantier, E., Mills, C., Sanudo, C. & Alfonsa, M. 2000. Household associations in home placement tests. Journal of Sensory Studies, 15 (2000), 421-436.

1989:
Guðjón Þorkelsson. 1989. The Effect of Processing on the Content of Polycyclic Aromatic Hydrocarbons and Volatile N-Nitrosoamines in Cured and Smoked Lamb Meat. In: Nutritional Impact of Food Processing (eds. JC Somogyi and HRMuller). Basel: Karger p. 188-198.

Sigurgeir Þorgeirsson, Stefán Sch. Thorsteinsson and Guðjón Þorkelsson. 1989. The influence of pre-slaughter grazing management on carcass composition and meat quality in lambs. Agricultural Science 3: 29-55. 1989.

Books

Guðjón Þorkelsson, Slizyte, R., Gildberg, A., Hörður G. Kristinsson. 2009. Fish proteins and peptides. Processing methods, quality and functionality.  In: Marine Functional Foods. Wageningen, Holland; Wageningen University Press, pp 115 - 133. About the book.

Guðjón Þorkelsson, Sjöfn Sigurgísladóttir, Margrét Geirsdóttir, Ragnar Jóhannsson, F Guérard, A Chabeaud, P Bourseau, L Vandanjon, P Jaouen, M Chaplain-Derouiniot, M Fouchereau-Peron, O Martinez-Alvarez, Y Le Gal, R Ravallec-Ple , L Picot, JP Berge, C Delannoy, G Jakobsen, I Johansson, I Batista, C.Pires. 2008. Mild processing techniques and development of functional marine protein and peptide ingredients In: Improving seafood products for the consumer. Edited by T. Börresen. Cambridge, Woodhead Publishing Ltd.  More about the book.

Guðjón Þorkelsson. Icelandic meat and meat products. Unhealthiness, loyalty and uniqueness
In: 'Science fascinates - Sigmundur Guðbjarnason 75 years old'. Háskólaútgáfan, Reykjavík, 2006.

Guðjón Þorkelsson and Óli Þór Hilmarsson, 1994. The Icelandic meat book: Handbook for meat buyers. Agricultural Information Service, 85 pages. ISBN 9979-60-074-8.

Herdís Steingrímsdóttir and Guðjón Þorkelsson: Assistive products for making bread. Iðnskólaútgáfan, 1982, 55 pages.


Articles in Conference proceedings

2011:

Guðjón Þorkelsson. Opportunities for improved utilization among farmers with small food production. Paper presented at the 2011 Agricultural Conference 2011.

2010:

Ragnheiður Héðinsdóttir, Guðjón Þorkelsson. Opportunities for meat processing in Iceland. Agricultural Research Council 2010, 7, p. 70-75.

Guðjón Þorkelsson, Óli Þór Hilmarsson, Þóra Valsdóttir. Thusmoked lamb. Agricultural Research Council 2010, 7, p. 82-86.

Ágúst Andersen, Óli Þór Hilmarsson, Guðjón Þorkelsson. Value from by-products in slaughter and meat processing. Agricultural Research Council 2010, 7, p. 87-91.

Rósa Jónsdóttir, Aðalheiður Ólafsdóttir, Óli Þór Hilmarsson, Guðjón Þorkelsson. Taste and pastures. Agricultural Research Council 2010, 7, p. 92-99.

2009:

G. Thorkelsson, R. Jonsdottir, OTHilmarsson, A. Olafsdottir and E. Martinsdottir. 2009. The influence of grazing time on Angelica archangelica on volatile compounds and sensory quality of meat from pasture lambs. 55th International Congress of Meat Science and Technology, Meat -Muscle, Manufacturing and Meals, 19th August 2009. Presentation.

Tao Wang, Rósa Jónsdóttir, Hordur G. Kristinsson, Gudjon Þorkelsson, Charlotte Jacobsen, Guðmundur Óli Hreggviðsson and Guðrún Ólafsdóttir. 2009.  Algal polyphenols as novel natural antioxidantsrway. Paper presented at the 3rd Joint Trans-Atlantic Fisheries Technology Conference, TAFT 2009. Sept. 15 - 18. Copenhagen, Denmark. Abstract

Guðjón Þorkelsson, Óli Þór Hilmarsson, Ásbjörn Jónsson and Valur N. Gunnlaugsson. Assessment of lamb slaughter and cooling of carcasses. Paper presented at the Agricultural Research Council 2009, 12 - 13 February, p. 338-345. Read the article.

Guðjón Þorkelsson. Developments and future prospects in food-related education. Paper presented at the Agricultural Research Council 2009, 12 - 13 February, p. 79. Read the article.

Guðjón Þorkelsson, Rósa Jónsdóttir, Aðalheiður Ólafsdóttir, Óli Þór Hilmarsson, Sigríður Jóhannesdóttir, Halla Steinólfsdóttir, Guðmundur Gíslason. Is there a different taste of lamb meat than lamb meat on a regular pasture ?. Academic Conference 2009. Read the article.

Sigrún Mjöll Halldórsdóttir, Patricia Y. Hamaguchi, Margrét Geirsdóttir, Guðjón Þorkelsson, Hörður G. Kristinsson and Arnljótur B. Bergsson. Antihypertensive properties of protein from whey and whey. Agricultural Research Council 2009, 12 - 13 February, 6th year, p. 375-379. Read the article.

2008:

Hamaguchi, P., Bergsson, A., Halldorsdottir.SM, Thorkelsson, G., Kristinsson, HG, Johannsson, R. 2008. Bioactivity of saithe (Pollachius virens L.) protein hydrolysates. proceedings of the 5th world fisheries congress, October 21-24, 2008, Yokohama, Japan. Abstract.

2007:
Guðjón Þorkelsson, Development of food from Icelandic agriculture with an emphasis on meat. Agricultural Research Council 4th volume 2007. p. 49-55. ISSN 1670-7230
 
2006:
Emma Eyþórsdóttir, Jóhannes Sveinbjörnsson and Guðjón Þorkelsson. Quality measurements of Icelandic lamb, genetic and environmental factors. Symposium on Icelandic animal husbandry in honor of Hjalti Gestsson's nineties. November 17, 2006

Guðjón Þorkelsson. Pros and cons of food processing. Speech at MNÍ Food Day, October 20, 2006.

Gudjon Thorkelsson. Curing and smoking of Icelandic lamb: Current practices and future outlook.
Proceedings of the International Dry-Cured Meat Congress. Oslo 7-9. June, 2006.

Gudjon Thorkelsson. 2006. Drying of lamb meat in the Faroe Islands - process, main defects and prevention. 
Proceedings of the International Dry-Cured Meat Congress. Oslo 7-9. June, 2006.

Guérard F., Chabeaud A., Laroque D., Denes A., Vandanjon L., Bourseau P., Jaouen P.,

Thorkelsson G. Towards the development of marine bio-ingredients with antioxidant properties: a case study. Second Joint Trans-Atlantic Fisheries Technology Conference-TAFT2006. Quebec City, Quebec, Canada Oct 29th-1st Nov. 2006. 

2005:
Jón Ragnar Gunnarsson, Sigurjón Arason, Guðjón Þorkelsson and Kristberg Kristbergsson. 2005. The Effects of Dryers on the Functional Properties of Fishmeal ”. 3rd Nordic Drying Conference, Karlstad, Sweden 15th - 17th June 2005. Content released on CD.

A.Chabeaud, L.Vandanjon, P.Burseau, R.Johannsson, G.Thorkelsson and F.Guérard. 2005. Evaluation of antioxidant activities in by-product hydrolysates: fractionation and concentration of active molecules using ultra- and nanofiltration membranes. 35th WEFTA Meeting Antwerp, Belgium, 19-22 / Oct. Proceedings. 

KA Thorarinsdottir, M.Geirsdottir, G. Thorkelsson, R. Johannsson, DE Ramsø, B. Gundesen and NK Sørensen. 2005. Properties of fish proteins isolated in a pilot plant. 35th WEFTA Meeting, Antwerp, Belgium, 19-22 / Oct. Proceedings. 

R. Johannsson, M. Geirsdóttir, G. Thorkelsson, I, Batista and C.Pires. 2005. Functional properties of proteins from seafood by-products. 2nd SEAFOODplus Conference Oct. 5., Granville, France. Published at: http://www.seafoodplus.org/Presentations_Open_Con.425.0.html

G. Thorkelsson. 2005. Marine Resources. Criteria for the Selection of Raw Material for Production of Proteins and Peptides. Health Sea International Symposium Oct. 6. Granville, France.

2004:
Inga Þórsdóttir and Guðjón Þorkelsson. 2004. Research studies in food and nutrition at the University of Iceland and SEAFOODplus. Lecture held on Food Day at Nordica Hotel in Reykjavík th. October 15, 2004

Birna Guðbjörnsdóttir, Hjörleifur Einarsson and Guðjón Þorkelsson. 2004. Attachment of bacteria to different surfaces in the seafood industry. The 19th INTERNATIONAL ICFMH SYMPOSIUM, FOOD MICRO 2004, 12 - 16 September, 2004, Portoro, Slovenia.

Margeirsson, S., Jónsson, GR, Arason, S. and Thorkelsson, G. 2004. Processing forecast of cod. The 34th WEFTA Annual Meeting Proceedings. September 12 - 15, 2004. Lübeck, Germany.

2003:
Kristín Anna Þórarinsdóttir, Guðný Guðmundsdóttir, Sigurjón Arason and Guðjón Þorkelsson. 2003. The effects of brine injection on yield, water holding capacity and chemical content of cod fillets. Proceedings of the TAFT 2003 conference. Pl. 56-57. ISBN 9979-74-005-1.

Manxue Mei, Guðný Guðmundsdóttir, Kristín Anna Þórarinsdóttir, Guðjón Þorkelsson, Sigurjón Arason, Kristberg Kristbergsson. 2003. Development of methods for evaluationg gel-forming properties in restructures fish products. 291-292. Proceedings of the TAFT 2003 conference. Pl. 56-57. ISBN 9979-74-005-1.

M. Mei, G. Gudmundsdottir, G. Thorkelsson, S. Arason, and K. Kristbergsson. 2003. Reforming fish cut-offs into fillets with texture resembling intact fish flesh. Proceedings of IFT Annual Meeting 2003.

Gudjon Thorkelsson. Novel components from by-products. Wefta Industry Forum Conference. September 19. 2003. 7. pp.

2002:
Guðjón Þorkelsson and Ólafur Reykdal. 2002. Sheep breeding. Product quality. Ministerial Conference 2002, p. 232-239, ISSN 1563-2520.

Gustaf Helgi Hjalmarsson, Sigurgeir Höskuldsson and Gudjon Thorkelsson. 2002. The effects of CAPTECH (Controlled Atmosphere Packaging Technology) on the shelf life of lamb meat. 14 p. Nordic Foodpack Seminar. Helsinki. September 4-6, 2002.

Guðjón Þorkelsson, Jónína Ragnarsdóttir, Stefán Sch. Thorsteinsson, Guðmundur Ö. Arnarsson, Þyrí Valdimarsdóttir and Birgitta Essen Gustavsson 2002. Muscle fiber characteristics and tenderness of M.longisimus dorsi of Icelandic lamb. Proceedings of the 48th International Congress of Meat Science and Technology in Rome, August 2002 p. 238-239.

2001:
Þyri Valdimarsdottir, Gudjon Þorkelsson, Carlos Sanudo, Matilde Alfonso and Alan Fisher, 2001. Comparison of Spanish and Icelandic trained sensory assessments and consumer preferences for European lamb meat. Poster at the Pangborn Symposium.

Þyri Valdimarsdóttir, Guðjón Þorkelsson and Stefán Sch. Thorsteinsson. 2001. Effects of feed and genotype on the texture and taste of lamb. Ministerial Conference 2001, p. 253-256, ISSN 1563-2520.

Margrét S. Sigurðardóttir and Guðjón Þorkelsson. 2001. Type of muscle fibers in Icelandic lamb. Ministerial Conference 2001, p. 257-260, ISSN 1563-2520.

Birna Baldursdóttir, Emma Eyþórsdóttir, Guðjón Þorkelsson, Helga Lilja Pálsdóttir, Óli Þór Hilmarsson and Rósa Jónsdóttir. 2001. Water resistance of pork. Ministerial Conference 2001, p. 265-268, ISSN 1563-2520.

Guðjón Þorkelsson, Baldur Þ. Vigfússon, Rósa Jónsdóttir and Ólafur Reykdal. 2001. Chemical composition of foal meat. Ministerial Conference 2001, p. 261-264, ISSN 1563-2520.

1979 – 2000:
Guðjón Þorkelsson, Stefán Sch. Thorsteinsson & Þyrí Valdimarsdóttir 2000. European project on lamb. I - Production systems, consumers, sampling, measurements. Ministerial Conference 2000, p. 2221-230, ISSN 1563-2520.

Stefan Sch. Thorsteinsson, Óli Þór Hilmarsson & Guðjón Þorkelsson. 2000. European project on lamb. II - Body language and tissue composition. In: Ministerial Conference 2000, p. 231-236, ISSN 1563-2520.

Þyrí Valdimarsdóttir, Soffía Jóhannsdóttir, Ólafur Unnarsson & Guðjón Þorkelsson 2000. European project on lamb. III - Consumer perception and attitudes. In: Ministerial Conference 2000, p. 237-246, ISSN 1563-2520.

Guðjón Þorkelsson, Stefán Sch. Thorsteinsson & Þyrí Valdimarsdóttir 2000. European project on lamb. IV -
Physical and chemical measurements. In: Ministerial Conference 2000, p. 246 - 247, ISSN 1563-2520.

Guðjón Þorkelsson. 2000. Aries experiments. Ministerial Conference 2000, p. 266-269, ISSN 1563-2520.

Sanudo, C. Alfonso, M. Sanches, A .; Pardos, JF; Sierra, I .; Berge, P .; Dransfield, E .; Sebastian, I .; Fisher, A .; Nute, G .; Stamataris, C .; Zyogoyannis, D .; Thorkelsson, G .; Thorsteinsson, S .; Piasantier, E .; Valusso, R .; Mill, CR 2000. Instrumental toughness of lamb from various European sheep types. Proceedings of the 46th ICoMST, Bueans Aieres, Argentina. p. 184-185.

Enser, M .; Nute, G .; Wood, J .; Sanudo, C .; Berge, P .; Zygoyiannis, D .; Thorkelsson, G .; Piasantier, E, E. and Fisher, A. 2000. Effects of production systewms on the fatty acids and flavor from six European countries. Proceedings of the 46th ICoMST, Bueans Aieres. p. 186-187.

Berge, P .; Sanchez, A .; Sanudo, C .; Thorkelsson, G .; Stamataris, C .; Piasantier, E. and Fisher A. 2000. Variation in muscle composition between different commercial lamb types and its relationship with meat texture. 2000. Proceedings of the 46th ICoMST, Bueans Aieres. p. 106-107.

Guðbjörnsdóttir, B., Gustavsson, P., Thorkelsson, G., Bredholt, S., Salo, S., M.-L. Suihko M.-L., Sjöberg A.-M. and Niclasen, O. 2000. Incidence ogf Listeria monocytogenes and Listeria species in some food processing plants in Nordic countries examined during 1998-1999. (Paper proceedings WEFTA Seafood Conference - June 2000).

Þyrí Valdimarsdóttir, Stefán Sch. Thorsteinsson, Rósa Jónsdóttir & Guðjón Þorkelsson. 1999. Sensory evaluation of meat from autumn-fed rams and geldings. In: Ministerial Conference 1999, 121–130.

Thorkelsson, G., Thorsteinsson, SS & Valdimarsdottir, T. 1999. Quality of lamb meat from different production systems in Europe. NJF Congress Report. Nordic Agricultural Research Nr. 3/1999. Volume 81: 316–320.

Fisher, AV, Nute, GR, Berge, P., Dransfield, E., Piasentier, E., Mills, CR, Sañudo, C., Alfonso, M., Thorkelsson, G., Valdimarsdottir, T., Zygoyiannis, D . & Stamataris, C. 1999. Variation in the eating quality of lamb from various European sheep types: assessment by trained taste panels in six countries. In: Proceedings of the 45th ICoMST in Yokohama. Vol I, 26–27.

Þyrí Valdimarsdóttir, Guðjón Þorkelsson and Stefán Scheving Thorsteinsson. 1998. Sensory Quality of Lamb Meat of Rams and Wethers of Different Ages. Meat Consumption and Culture, 44th International Congress of Meat Science and Technology 30.8 - 4.9 1998. Congress Proceedings. ITRA. EUROCARNE. INIA p. 778.

Rósa Jónsdóttir, Þyrí Valdimarsdóttir, Guðjón Þorkelsson and Birna Baldursdóttir. 1998. Influence of Fish Oil in Feed on Fatty Acid Composition and Sensory Quality of Pork. Meat Consumption and Culture, 44th International Congress of Meat Science and Technolgy 30.8. -4.9. Congress Proceedings. ITRA. EUROCARNE. INIA p.779.

Birna Baldursdóttir, Guðjón Þorkelsson, Þyrí Valdimarsdóttir and Rósa Jónsdóttir. 1997. Fat in the feed of farmed pigs. Ministerial Conference 1997: 276 - 286.

Guðjón Þorkelsson 1997. Extension of slaughter time: quality issues and product development. Ministerial Conference 1997: 72 - 75.

Guðjón Þorkelsson 1997. Project: Food hygene; implementation of HACCP in the Food industry. The 3rd Nordfood Conference 23. - 25. 10. 1997., 4 bls.

Guðjón Þorkelsson 1996. Use of films and coatings in Icelandic meat products. Flair flow course organized by IFL 29. - 30.4.1996. Polygraph. 6 p.

Þyrí Valdimarsdóttir and Guðjón Þorkelsson, 1996. Taste quality in Icelandic lamb. Ministerial Conference 1996: 194 - 205.

Guðjón Þorkelsson, Ylva Bergquist, Kertin Lundström and Rósa Jónsdóttir 1996. Fatty acid composition of M.Longissimus dorsi of different fat grades of Icelandic lamb. Meat for the consumer, 42nd International Congress of Meat Science and Technolgy. Sept. 1-6. 1996. Poster Proceedings. Matforsk.

Ólafur Reykdal, Arngrímur Thorlacíus and Guðjón Þorkelsson, 1996. Cadmium in livers and kidneys of Icelandic lambs. In: Meat for the Consumer, 42nd International Congress of Meat Science and Technolgy, Sept. 1-6. Poster Proceedings. Matforsk, Ås, 29 - 30.

Rósa Jónsdóttir, Guðjón Þorkelsson and Guðmundur Haraldsson, 1996. Influence of dietary fishmeal and fatty acid composition and eating quality of pigs. In: Meat for the Consumer, 42nd International Congress of Meat Science and Technolgy, Sept. 1-6. Poster Proceedings. Matforsk, Ås, 218 - 219.

Guðjón Þorkelsson and Einar Mattíasson. 1995. Animal derived food products of the next years Nordiska Jordbruksforskares Förening XX: e kongress, Reykjavik 26-29.6.1995. 4 NJF 2 1995, 56-59.

Ylva Bergquist, Kerstin Lundström and Guðjón Þorkelsson. 1995. Effect of grading on fatty acid composition of Icelandic Lamb. Production of lamb meat in accordance with market demands. NJF seminar no.256. Hvanneyri 23-24.6.1995. NJF 4 1995, p 184.

Guðjón Þorkelsson. 1995. Traditional and special lamb products in Iceland. Production of lamb meat in accordance with market demands. NJF seminar no.256. Hvanneyri 23-24.6.1995. NJF 4 1995, p 187.

Guðjón Þorkelsson. 1995. Development of lamb meat products in Iceland. Production of lamb meat in accordance with market demands. NJF seminar no.256. Hvanneyri 23-24.6.1995. NJF 4 1995, p 192.

Guðjón Þorkelsson. 1994. Lamb, research and development project. Ministerial Conference 1994: 12 - 18.

Guðjón Þorkelsson. 1994. Comparison of Icelandic bulls and Galloway hybrids. III. Products. Ministerial Conference 1994: 133-142.

Ólafur Reykdal and Guðjón Þorkelsson. Purity of dairy products. Ministerial Conference 1993: 72-80.

Guðjón Þorkelsson. Experiment with the breaking of dilka meat in the autumn of 1989. Ministerial meeting 1990: 122-139.

Guðjón Þorkelsson: Production of processed meat products. Ministerial Conference 1989: 226-240.

Ragnheiður Héðinsdóttir, Guðjón Þorkelsson and Þyrí Valdimarsdóttir. Chemical measurements of agricultural products. Ministerial Conference 1989: 216 - 225.

Guðjón Þorkelsson and Ragnheiður Héðinsdóttir. Innovations in meat processing and treatment. Ministerial Conference 1988: 71-75 and Yearbook of Agriculture 1987: 302-314

Guðjón Þorkelsson. Improving Meat Quality in Iceland. Paper presented at the NJF conference in Aarhus in July 1987. Abstract in: Nordisk jordbruksforskning 69, 2 p.

Guðjón Þorkelsson. The Effects of Processing on the Amount of Polycyclic Aromatic Hydrocarbons and Volatile N-Nitrosoamines in Cured and Smoked Lamb Meat. In: Abstracts of the Symposium on the Nutritional Impact of Food Processing. Reykjavik 2-4.9.1987, 1 p.

Sigurgeir Þorgeirsson, Stefán Sch. Thorsteinsson and Guðjón Þorkelsson. Carcass Measurements and Grading as Indicators of Tissue Composition in Icelandic Lamb. In: Summaries 37th Annual Meeting of EAAP, vol.II, 1 p.

Guðjón Þorkelsson, Jón Óttar Ragnarsson and Stefán Aðalsteinsson: The Effect of Autumn Grazing on the Fatty Acid Composition of Adipose and Muscle Tissue in Lambs. The 13th Scandinavian Symposium on Lipids. Reykjavik June 30 - July 3 1985. An abstract.

Guðjón Þorkelsson and Sigurgeir Þorgeirsson. Shelf life and fatigue of dilka meat. Ministerial meeting of B.Í and RALA 1983, 7 pages.

Guðjón Þorkelsson, Stefán Aðalsteinsson, Jón Óttar Ragnarsson and Hannes Hafsteinsson. The effect of autumn grazing on the quality of dilka falls. Ministerial meeting B.Í / RALA 1979, 10 pages.

Speeches at conferences

Minh Van Nguyen, Kristín Anna Þórarinsdóttir, Guðjón Þorkelsson, Ágústa Guðmundsdóttir, Sigurjón Arason. Effects of the anti-caking agent potassium ferrocyanide (K4[Fe (CN)6]) on lipid oxidation of salted cod (Gadus morhua) during salting, storage and rehydration. Presentation: 41st WEFTA Meeting, 27-30 September 2011, Gothenburg, Sweden.

Guðjón Þorkelsson. 2005. Targeted food from fish - Opportunities, laws and rules. Paper presented at a SEAFOODplus meeting hosted by IFL, the University of Iceland and the French Embassy in Iceland at the Grand Hotel in Reykjavík, 6 May 2005.

Guðjón Þorkelsson. Use of fish proteins in food processing. Food research in the North: Cooperation between Ha and IFL in the field of food research. Paper presented at a conference in Akureyri on November 23, 2004.

G.Thorkelsson, I.Batista, C.Delannoy, I.Johannsson, J.Gislason, F.Guerard, JM.Pcicot, JP.Berger, P.Bourseau and Y.LeGal. 2004. High added value functional seafood products for human health from seafood by-products by innovative mild processing. The first SEAFOODplus Conference, Copenhagen, Oct. 4.-6. 2004.

G. Thorkelsson, K. Stefansdottir, I. Batista, C. Delannoy, I. Johannsson, J. Gislason, R. Johannsson, F. Guérard, JM. Piot, JP. Bergé, P. Bourseau, P.Jaouen & Y. Le Gal. 2004. Fish Protein hydrolysates. Proximate analysis and physical properties. The first SEAFOODplus Conference, Copenhagen, Oct. 4.-6. 2004.

F. Guérard, MT. Sumaya-Martinez, B. Linard, M. Fouchereau-Péron, R.Ravallec-Plé, R. Johannsson, I.Fruitier-Arnaudin, S. Bordenave-Juchereau, F. Sannier, JM. Piot, JP. Bergé, P. Bourseau, L.Vandanjon, P. Jaouen, C. Delannoy, I. Batista, I. Johannsson, G. Thorkelsson, R. Johannsson, J. Gislason & Y. Le Gal. 2004. Marine waste upgrading: Hydrolysates with biological properties - 1. The first SEAFOODplus Conference, Copenhagen, Oct. 4.-6. 2004.

F. Guérard, MT. Sumaya-Martinez, B. Linard, M. Fouchereau-Péron, R.Ravallec-Plé, R. Johannsson, I.Fruitier-Arnaudin, S. Bordenave-Juchereau, F. Sannier, JM. Piot, JP. Bergé, P. Bourseau, L.Vandanjon, P. Jaouen, C. Delannoy, I. Batista, I. Johannsson, G. Thorkelsson, R. Johannsson, J. Gislason & Y. Le Gal. 2004. Marine waste upgrading: Hydrolysates with biological properties - 2. The first SEAFOODplus Conference, Copenhagen, Oct. 4.-6. 2004.

Guðjón Þorkelsson, Jóhannes Sveinbjörnsson and Emma Eyþórsdóttir. 2004. Measurements of the quality of lamb in experiments on Hesti. RALA-erindi. 25.03.2005.

Guðjón Þorkelsson and Emma Eyþórsdóttir. Quality measurements of lamb. Open day at Hesti in Borgarfjörður. March 12, 2004

Guðjón Þorkelsson. 2003. SEAFOOD PLUS - benefits for Iceland. IFL's autumn meeting, Reykjavík 13 November.

Guðjón Þorkelsson, Jónína Ragnarsdóttir, Stefán Sch. Thorsteinsson, Guðmundur Ö. Arnarsson, Þyrí Valdimarsdóttir and Birgitta Essen Gustavsson 2002. Muscle fiber characteristics and tenderness of M.longisimus dorsi of Icelandic lamb. Paper presented at a workshop of the Nordic Network of Meat Science in Hamar, Norway in June 2002.

P. Gustavsson, S.Salo, O.Nicklassen, B. Gudbjörnsdóttir, G. Torkelsson, S.Bredholt, M.-L.Suihko, I. Karlsson and CGJanson. 2001. Combating Listeria monocytogenes in Nordic food plants: NordSafety - a database for the future. 5 pp. Food factory of the future. Seminar June 27-29 2001, Gothenburg, Sweden. Organized by SIK, The Swedish Institute for Food and Biotechnology, in collaboration with EFFoST and Flair-Flow.

Guðjón Þorkelsson 1996. Icelandic horse meat and horse meat products. NOVA course on the Icelandic horse. Hvanneyri 7.-8. August. Polygraph. 15 p.

 
Reports

2013:

Vigfús Ásbjörnsson, Óli Þór Hilmarsson, Ingunn Jónsdóttir, Guðjón Þorkelsson, Guðmundur Stefánsson. Filleting capelin for developing marinated anchovies / Filleting capelin for developing marinated anchovies. Matís Report 29-13, 19 p. Closed report. Report summary.

2012:
Vigfús Ásbjörnsson, Haraldur Hallgrímsson, Jón Trausti Kárason, Óli Þór Hilmarsson, Guðjón Þorkelsson. Cheese production in Öræfi - Fýsileiki og Chance / Cheese production in Öræfi. Matís Report 40-12, 14s. Closed report.

Gunnþórunn Einarsdóttir, Guðjón Þorkelsson. Workshop on SMEs and Nordic Food Competence Centers - New Nordic Food II / Workshop on food factories and new Nordic foods. Matís Report 21-12, 19 p.

Guðjón Þorkelsson, Anna Lára Sigurðardóttir, Vigfús Ásbjörnsson, Sandra Rún Jóhannesdóttir, Gunnþórunn Einarsdóttir, Kolbrún Sveinsdóttir, Valgerður Lilja Jónsdóttir. Efling grænmetisræktar á Íslandi / Increased opportunities in Icelandic vegetable production. Matís Report 16-12, 42 p.

2011:
Jón Trausti Kárason, Irek Klonowski, Guðjón Þorkelsson. Nasl and fish proteins - Development of processing methods and products / Fish proteins used in extruded corn snacks. Matís Report 35-11, 16 p. Closed report. Report summary.

Guðjón Þorkelsson, Ágúst Andrésson, Óli Þór Hilmarsson, Ásbjörn Jónsson, Ólafur Reykdal. Value from by-products of slaughter and meat processing. Report for the year 2009. Matís report 32-11, 16 p. Closed report. Report summary.

Þóra Valsdóttir, Rakel Eva Sævarsdóttir, Gunnþórunn Einarsdóttir, Guðjón Þorkelsson, Aðalheiður Ólafsdóttir, Kolbrún Sveinsdóttir. Icelandic baby food - market and public requirements. Matís Report 07-11, 44 s.

Óli Þór Hilmarsson, Guðjón Þorkelsson, Davíð Freyr Jónsson, Gunnþórunn Einarsdóttir. Preliminary study on the processing and marketing of Icelandic crabs / Crab; fishing, processing and marketing. Preliminary study. Matís Report 03-11, 5 p. Report summary.
2010:
Kristín Anna Þórarinsdóttir, Sigurjón Arason, Guðjón Þorkelsson. The role and fate of added phosphates in salted cod products / The role and fate of added phosphate in salted fish. Matís Report 27-10, 28 s.

Þóra Valsdóttir, Óli Þór Hilmarsson, Guðjón Þorkelsson. Air-dried lamb. Final report / Air dried lamb meat. Final report. Matís Report 19-10, 17 p.

Þóra Valsdóttir, Guðjón Þorkelsson, Irek Klonowski. Use of saithe in ready-made fish products - final report / Using saithe in ready to eat fish product - final report. Matís Report 06-10, 16 p. Closed report

Þóra Valsdóttir, Guðjón Þorkelsson, Irek Klonowski. Use of saithe in ready-made fish products / Using saithe in ready to eat fish product. Matís Report 05-10, 16 s.

2009:
Rósa Jónsdóttir, Aðalheiður Ólafsdóttir, Óli Þór Hilmarsson and Guðjón Þorkelsson. Taste and pastures. Matís Report 45-09, 11 p. Closed report. Report summary.

Gunnþórunn Einarsdóttir, Emilía Martinsdóttir, Þóra Valsdóttir and Guðjón Þorkelsson. Development of bakery products made from Icelandic corn. Matís report 29-09. 7 s.

Margeir Gissurarson, Ragnheiður Sveinþórsdóttir, Þorgrímur Kjartansson, Sigurjón Arason, Guðjón Þorkelsson, Sindri Sigurðsson, Jón Helgason and Björn Erlendsson. Improved processing of capelin roes. Matís Report 16-09, 28 p. Closed report. Report summary

Aðalheiður Ólafsdóttir, Ólafur Reykdal, Óli Þór Hilmarsson, Gunnþórunn Einarsdóttir, Kolbrún Sveinsdóttir, Þóra Valsdóttir, Emilía Martinsdóttir, Guðjón Þorkelsson. Product development of healthier processed meat products. Matís Report 25-09, 111 p. Report summary.

Guðjón Þorkelsson, Rósa Jónsdóttir, Aðalheiður Ólafsdóttir and Óli Þór Hilmarsson. Grazing on Angelica archangelica and flavor of lamb meat / Grazing on Angelica archangelica and flavor of lamb meat. Matís Report 20-09, 36 p.

Ragnar Jóhannsson, Sjöfn Sigurgísladóttir, Guðjón Þorkelsson, Arnljótur B. Bergsson. Pure muscle proteins from fish. Matís Report 19-09, 10 s.

Guðjón Þorkelsson, Hörður G. Kristinsson. Bioactive Peptides from Marine Sources. State of Art. Report to the NORA fund. Matís Report 14-09, 19 p.

Patricia Y. Hamaguchi, Sigrún Mjöll Halldórsdóttir, Hörður G. Kristinsson, Arnljótur Bjarki Bergsson, Guðjón Þorkelsson. Bioactive properties of whey proteins / Bioactive properties of whey proteins. Matís report 06-09, 7 s.

Valur Norðri Gunnlaugsson, Óli Þór Hilmarsson, Ásbjörn Jónsson, Guðjón Þorkelsson. 2009. Assessment of lamb slaughter and lamb chilling in autumn 2008. Matís Report 05-09, 30 p.

2008:

Guðjón Þorkelsson, Þóra Valsdóttir, Guðrún Anna Finnbogadóttir, Sigrún Mjöll Halldórsdóttir. 2008. Markets for fish protein. Analysis of products on the market. Matís report 07-08. 57 p.

Sigrún Mjöll Halldórsdóttir, Guðjón Þorkelsson, Þóra Valsdóttir, 2008. HEALTHY DIET? Summary of the main categories of health foods and scientific evidence of their effectiveness. Matís report 19-08, 75 p.

Sigrún Mjöll Halldórsdóttir, Patricia Y. Hamaguchi, Ragnar Jóhannsson, Sigurður Hauksson, Hörður G. Kristinnsson, Guðjón Þorkelsson, 2008. Chemical composition and properties of saithe isolate. Matís report 20-08, 12 pages.

Guðjón Þorkelsson, Margrét Geirsdóttir, Ragnar Jóhannsson, Sigurður Hauksson, Sjöfn Sigurgísladóttir, Arnljótur Bjarki Bergsson, 2008. Fish protein as a dietary supplement. Matís report 11-08, 18 p.

Arnljótur B. Bergsson, Margrét Geirsdóttir, Rósa Jónsdóttir, Þóra Valsdóttir, Hörður G. Kristinsson, Guðjón Þorkelsson. 2008. A brief summary of processing fish proteins. Matís report 36-08. Closed report.

2007:
Ásbjörn Jónsson, Guðrún Anna Finnbogadóttir, Guðjón Þorkelsson, Hannes Magnússon, Ólafur Reykdal, Sigurjón Arason, 2007. Dried fish as health food.  Matís report 32-07, 22 p.

Sigurður Vilhelmsson, Guðmundur Gunnarsson and Guðjón Þorkelsson, 2007. Isolation and processing of bioactive peptides from underutilized species of marine organisms - preparation and formation of networks. Matís Report 11-07, 14 p.

Lárus Freyr Þórhallsson, Margrét Geirsdóttir, Guðmundur Óli Hreggviðsson, Sigurður Vilhelmsson, Guðjón Þorkelsson, 2007. Blood pressure lowering effect (Ace-inhibiting activity) in Icelandic seafood - installation of measurement methods. Matís Report 10-07, 15 p.

Ásbjörn Jónsson, Guðrún Anna Finnbogadóttir, Guðjón Þorkelsson, Hannes Magnússon and Ólafur Reykdal, 2007. Dried fish as a health food. Matís report 09-07, 25 p.

2006:
Margrét Bragdóttir, Irek Klonowski, Guðjón Þorkelsson. 2006. Fish scent. Drying conditions and shelf life. IFL report 33-06, 19 pages.
 
Irek Klonowski, Volker Heinz, Stefan Toepfl, Guðjón Gunnarsson, Guðjón Þorkelsson. 2006. The use of electrical pulses to improve the utilization of marine products. IFL report 06-06, 14 p.

Guðjón Gunnarsson, Irek Klonowski, Guðjón Þorkelsson. 2006. Freeze-drying of seafood - Exploration of possibilities. IFL report 05-06, 14 p.

2005:
Þóra Valsdóttir, Þorvaldur Þóroddsson, Guðjón Þorkelsson, Sigurjón Arason, Kristín Anna Þórarinsdóttir. 2005. Production of shaped fish pieces and gel block from cuttings and marlin: Upscaling of the use of fish glue in shaped fish pieces. IFL report 21-05, 18 p.

Helga Gunnlaugsdóttir, Guðjón Þorkelsson. 2006. Bioactive substances in Icelandic seafood: Summary report. IFL report 06-06, 47 p.

Helga Gunnlaugsdóttir, Margrét Geirsdóttir, Arnheiður Eyþórsdóttir, Hjörleifur Einarsson, Guðjón Þorkelsson. 2005. Bioactive substances in Icelandic seafood: Summary. IFL report 05-05, 20 p.

Þorvaldur Þóroddsson, Guðjón Þorkelsson, Sigurjón Arason, Kristín Anna Þórarinsdóttir. 2005. Flow salting of herring products. IFL report 21-05, 18 pages.

2004:
Kristín Anna Þórarinsdóttir, Guðný Guðmundsdóttir, Sigurjón Arason, Guðjón Þorkelsson. 2004. The effects of added soy and fish proteins on changes in weight, water holding capacity and chemical content during frozen storage of cod (Gadus morhua) fillets. Progress Report to the EU, QLK1-CT-2000-01017 Fishery by-products, July 2004, 17 p.

Guðjón Þorkelsson. 2004. Propehealth. - Annual progress report to SEAFOODplus. 15 p. november2004.

Guðjón Þorkelsson. 2004. Propephealth. - 2.nd. progress report. SEAFOODplus. September 2004.

Guðjón Þorkelsson. 2004. Propephealth. - 1st Progress report to SEAFOODplus. May. 2004.

Guðjón Þorkelsson, Jónína Ragnarsdóttir, Ásbjörn Jónsson, Ása Þorkelsdóttir, Eyjólfur K. Örnólfsson and Emma Eyþórsdóttir. 2004. Muscle fibers and properties of mutton. Final report to RANNÍS, September 2004. 41 pages.

2003:
Kristín Anna Þórarinsdóttir, Sigurjón Arason and Guðjón Þorkelsson (2003). IFL project report to Rannís, 14-03: Light salting, stability and utilization of frozen products. Experiments II, III and IV. Processing and measuring methods for cod fillets.

Kristín Anna Þórarinsdóttir, Sigurjón Arason and Guðjón Þorkelsson (2003). IFL project report to Rannís, 07-03: Light salting, stability and utilization of frozen products. Experiment II - Effect of phosphate and soy protein use in injection salting and pickling of cod fillets.

Guðný Guðmundsdóttir, Kristín Anna Þórarinsdóttir, Sigurjón Arason and Guðjón Þorkelsson (2003). IFL project report to Rannís, 09-03: Light salting, stability and utilization of frozen products. Experiment III - Effects of the use of phosphate and fish proteins (cod powder) in injection salting and pickling.

Guðný Guðmundsdóttir, Kristín Anna Þórarinsdóttir, Sigurjón Arason and Guðjón Þorkelsson (2003). IFL project report to Rannís, 10-03: Light salting, stability and utilization of frozen products. Experiment IV - Effects of using fish proteins (FPH and minced fish muscles) and soy proteins in injection salting and pickling.

Kristín Anna Þórarinsdóttir, Guðný Guðmundsdóttir, Sigurjón Arason and Guðjón Þorkelsson (2003). IFL project report to Rannís, 11-03: Light salting, stability and utilization of frozen products. Comparison of Experiments II and III. Effects of using fish and soy proteins with / without salt and phosphate.

Kristín Anna Þórarinsdóttir, Guðný Guðmundsdóttir, Sigurjón Arason and Guðjón Þorkelsson (2003). IFL project report to Rannís, 12-03: Light salting, stability and utilization of frozen products. Comparison of Experiments II, III and IV. Effects of using soy proteins and fish proteins in different forms.

Kristín Anna Þórarinsdóttir, Guðný Guðmundsdóttir, Sigurjón Arason and Guðjón Þorkelsson (2003). IFL project report to Rannís, 13-03: Light salting, stability and utilization of frozen products. Summary of the main results of all work components.

Development of lamb meat production and market in Greenland 2000 - 2002. Report to NORA. Norrönt Atlantssamstarv. February 2003. 8 p.

Birna Guðbjörnsdóttir, Guðjón Þorkelsson, Árni Sigurðsson and Ragnheiður Halldórsdóttir (2003). Guidance on hygienic design for manufacturers of food processing equipment. Project report 19-03. 25s.

2002:
Guðjón Þorkelsson and Gústaf Helgi Hjálmarsson. 2002. Effect of packaging with CAPTECH (Controlled Atmosphere Packaging Technology) on the shelf life of lamb. 23. p. IFL report 07-02.

Guðjón Þorkelsson. 2002. Sharp meat. Fat composition and quality ratio. Report to the NORA Foundation. 4 p.

Guðjón Þorkelsson, Stefán Sch. Thorsteinsson, Jónína Ragnarsdóttir, Guðmundur Örn Arnarsson, Þyrí Valdimarsdóttir and Emma Eyþórsdóttir. Type of muscle fibers and fatness of Icelandic lamb meat. IFL project report to RANNÍS, 12-02. 80 p. July 2002

2001:
Guðjón Þorkelsson. 2001. Classification of lamb carcasses at Neqi a / si Narsaq. Report to the NORA Foundation. 9 p.

Guðjón Þorkelsson. 2001. Comparison between Neqi's slaughterhouse and Icelandic slaughterhouses. Report to Neqi a / s. 6 p.

Gunnar Páll Jónsson & Guðjón Þorkelsson. S - Icelandic wild game, utilization, safety and quality. - Report Rf 01 -2001.

Brynjólfur Eyjólfsson, Sigurjón Arason, Gunnar Stefánsson and Guðjón Þorkelsson. 2001. Cod carcasses, processing efficiency and processing management. Report IFL 2-2001.

Rósa Jónsdóttir, Guðjón Þorkelsson, Helgi í Brekkunum and Birna Mörköre. 2001. Fatty acid composition ofg Faeroese lamb meat. Project Report to NORA Rf 36-01. December. 2001. 40 p.

Kristín Anna Þórarinsdóttir, Sigurjón Arason and Guðjón Þorkelsson (2001). IFL project report to Rannís, 18-01: Light salting, stability and utilization of frozen products. Needs analysis results.

Kristín Anna Þórarinsdóttir, Sigurjón Arason and Guðjón Þorkelsson (2001). IFL project report to Rannís, 19-01: Light salting, stability and utilization of frozen products. Effects of freezing and brine on physical and chemical changes in fish flesh.

Kristín Anna Þórarinsdóttir, Sigurjón Arason and Guðjón Þorkelsson (2001). IFL project report to Rannís, 20-01: Light salting, stability and utilization of frozen products. Preliminary experiments. Effects of brine concentration, brine time and ratio of fish to brine.

Kristín Anna Þórarinsdóttir, Sigurjón Arason and Guðjón Þorkelsson (2001). IFL project report to Rannís, 21-01: Light salting, stability and utilization of frozen products. Experiment I - Comparison of the effects of syringe salting and brine.

2000:
Guðjón Þorkelsson and Erlendur Á. Garðarsson. 2000. Measures to increase the efficiency of slaughter and processing of horsemeat for export. Report to the Agricultural Productivity Fund. 5 p.

Guðjón Þorkelsson and Erlendur Á. Garðarsson. 2000. Measures to increase efficiency in slaughtering and processing horsemeat for export. Report to the Agricultural Productivity Fund. 5 p. Opinion.

1999:
Birna Baldursdóttir, Rósa Jónsdóttir, Þyrí Valdimarsdóttir and Guðjón Þorkelsson, 1999. Low-fat fishmeal in feed.

Þyrí Valdimarsdóttir, Stefán Sch. Thorsteinsson, Rósa Jónsdóttir & Guðjón Þorkelsson. 1999. Sensory evaluation of meat from autumn-fed rams and geldings. In: Ministerial Conference 1999, 121–130.

Guðjón Þorkelsson. 1999. Development of horsemeat exports. Final report to RANNÍS. Nr. 95081-0098. 15 p.

Foreign Á. Garðasson and Guðjón Þorkelsson.1999. Sea transport of chilled horsemeat to Rotterdam. Report to Meat Producers. 11 p.

Erlendur Á Garðarsson and Guðjón Þorkelsson 1999. Attempt to export boned lamb to Gate Gourmet in Denmark. Report to Meat Producers and the National Association of Sheep Farmers. 5 p.

1998:
Birna Baldursdóttir, Guðjón Þorkelsson, Þyrí Valdimarsdóttir and Rósa Jónsdóttir. 1998.

Fat in piglet feed. Fölrit RALA no. 195.

Rósa Jónsdóttir, Hörður Kristinsson, Einar Sigurðsson and Guðjón Þorkelson.1998 Impact

fatty acid compositions of lard on the quality of pepperoni. Fjölrit RALA nr. 196. 26 p.

Þyrí Valdimarsdóttir, Stefán Sch.Thorsteinsson, Óli Þór Hilmarsson, Ólafur Unnarsson,

Rósa Jónsdóttir and Guðjón Þorkelsson. Sensory quality of autumn-fed rams and

geldings. Final report ril RANNÍS, Dec. 1998, 15 p.

Hjörleifur Einarsson, Birna Guðbjörnsdóttir, Guðjón Þorkelsson (1998), Hreinlæti og

cleaning, Fisheries Research Institute. Project report to RANNÍS 02-98, 17 p.

1997:
Guðjón Þorkelsson, 1997. Exports of fresh dilka meat in whole carcasses. Experimental slaughter and packing. Comparison of shelf life in conventional refrigerated containers and aerated refrigerated containers. Fjölrit 10 bls.

Guðjón Þorkelsson, 1997. Development of horsemeat exports. Final report to the RANNÍS Technical Fund, 5 pages.

Jón Áki Leifsson, Guðjón Þorkelsson, Hjörleifur Einarsson, Ása Þorkelsdóttir, Þyrí Valdimarsdóttir and Hannes Hafsteinsson. 1997. Impact of Sous Vide processing on taste and microorganisms in salmon, beef, sauces and vegetables. Report to the Rannís Technical Fund.

1996:
Guðjón Þorkelsson and Þyrí Valdimarsdóttir.1996 Feeding of farmed pigs. Comparison of the effect of two feed mixtures on meat quality. Report prepared for Mjólkurfélag Reykjavíkur and Síld og fisk. 12 p.

Gunnar Ríkharðsson, Guðjón Þorkelsson, Þóroddur Sveinsson and Ólafur Guðmundsson. Comparison of Icelandic bulls and Galloway hybrids. Fjölrit RALA nr. 186, 45 p.

1995:
Birna Baldursdóttir and Guðjón Þorkelsson, 1995. The effect of fishmeal and fat on the quality of pork. Fjölrit RALA nr. 177, 30 p.

1994:
Guðjón Þorkelsson: Comparison of Icelandic bulls and Galloway hybrids. III Products. Ministerial Conference 1994: 133-142.

Ólafur Reykdal and Guðjón Þorkelsson: Chemical composition and utilization of lamb. Fjölrit RALA, 176, 44 bls.

Sigurgeir Höskuldsson, Guðjón Þorkelsson: Drying effect on meat. Summary. Report to the Professional Council for Sheep Breeding. October. Fjölrit, 17 p.

Sigurgeir Höskuldsson and Guðjón Þorkelsson. Experiments with the production of reshaped meat. Report to the National Association of Sheep Farmers and the Agricultural Productivity Fund. July 1994. 27 p.

1993:
Guðjón Þorkelsson. A study of the quality of beef from Icelandic beef and Galloway hybrids. Interim report to the National Association of Cow Farmers, 11 pages.

Guðjón Þorkelsson. Examination of the quality of ground beef, hamburgers and beef tenderloin in June 1993. Report to the National Association of Cow Farmers, 10 pages.

Guðjón Þorkelsson. New ways of salting and smoking ham. Final report to the National Investigation Council, 23 pages.

Guðjón Þorkelsson and Níels Hjaltason: Cutting of unfrozen dilka meat during the slaughter season. Report to the Collaborative Group on the sale of lamb, 8 pages.

Guðjón Þorkelsson, Ólafur Reykdal and Óli Þór Hilmarsson: The effect of quality categories on utilization, nutritional value and processing value of dilka meat pieces. Interim report to the National Association of Sheep Farmers, 13 pages.

Ólafur Reykdal, Arngrímur Thorlacíus and Guðjón Þorkelsson 1993. Heavy metals in lamb feed. Interim report to the National Association of Sheep Farmers, 2 pages.

Ragnheiður Héðinsdóttir, Þorgeir Hlöðversson and Guðjón Þorkelsson. Shaped meat. Report to the Government Research Council and the Agricultural Productivity Fund. 25 p.

1992:
Guðjón Þorkelsson: Revision of the evaluation of beef. Report to the National Association of Cow Farmers, August, 20 pages.

Guðjón Þorkelsson: Packing and distribution of fresh and unfrozen meat. Report to the Collaborative Group on the sale of lamb, September, 16 pages.

Guðjón Þorkelsson, Ragnheiður Héðinsdóttir and Óli Þór Hilmarsson. Market for fresh and unfrozen dilka meat. Report to the Collaborative Group on Lamb Meat, September, 43 pages.

Ragnheiður Héðinsdóttir, Guðjón Þorkelsson and Óli Þór Hilmarsson: Utilization of large dilka bodies. Report to the National Association of Sheep Farmers, February, 15 pages.

1991:
Guðjón Þorkelsson: Quality of lard in Iceland. Effect of feed on fatty acid composition. - Confidential report.

Guðjón Þorkelsson: Electrical stimulation of dilka meat. Final report to the Research Council, 35 pages.

Guðjón Þorkelsson: An audit of Bautabúr's operations. Confidential report 35 p.

Guðjón Þorkelsson and Ólafur Reykdal. Introduction to the food department. RALA. newsletter, 1, 4 p.

Guðjón Þorkelsson and Rangheiður Héðinsdóttir. Production, distribution and sale of fresh dilka meat. RALA, newsletter 6, 8 pages.

Guðjón Þorkelsson and Ragnheiður Héðinsdóttir. Product descriptions for processed meat products. Fjölrit RALA 150, 46 bls.

1990:
Guðjón Þorkelsson: The effect of breaking dilka meat during the slaughter season on slaughter costs. Report on an experiment in the autumn of 1991. Fjölrit RALA 142, 18 pages.

Guðjón Þorkelsson: Experiment with breaking dilka meat in the autumn of 1989. Ministerial meeting 1990: 122-139.

Guðjón Þorkelsson, Processed meat products. Content rules. Diet. Journal of food science students. 5:15.

1990:
Guðjón Þorkelsson, 1990. Evaluation of KBB's meat processing. Confidential report to Kaupfélag Borgfirðingar.

1989:
Guðjón Þorkelsson. A Report to the WKKellogg Foundation on the Food Science Program 1988. 1.3.1989. Polygraph. 5 p.

Sigurgeir Þorgeirsson, Stefán Sch. Thorsteinsson, Guðjón Þorkelsson, Ragnheiður Héðinsdóttir, Grímur Ólafsson and Níels Rafn Guðmundsson: Comparison of utilization and value of dilka meat in different quality categories. Yearbook of Agriculture 38, 222-249.

1988:
Guðjón Þorkelsson. Acidity and quality assessment of meat. Copies for slaughterhouse courses, 10 pages.

Guðjón Þorkelsson. Annual Report to the WK Kellogg Foundation. 1.2.1988 Fjölrit, 5 p.

Guðjón Þorkelsson. A Report to the WKKellogg Foundation on the Food Science Program in Iceland 1987 - 1988. 15.8.1988. Fjölrit, 9 p.

Guðjón Þorkelsson, Níels Rafn Guðmundsson and Grímur Ólafsson: Breaking of dilka meat. Storage space and utilization. Report to KBB. 15.9. Fjölrit 11 bls.

Níels Rafn Guðmundsson and Guðjón Þorkelsson: New ways of treating dilka meat after freezing. Report to KBB in October 1988. Fjölrit.

1986:
Guðjón Þorkelsson and Ragnheiður Héðinsdóttir: Survey on egg quality 22.8 - 26.8 1986. Report to the Ministry of Agriculture. 20 p.

Ólafur Reykdal, Ágúst Ó. Sigurðsson and Guðjón Þorkelsson. 1986. Chemical analysis of meat 1984 - 1986. Fjölrit RALA 120, 93 p.

Guðjón Þorkelsson: Packing fresh meat in air-conditioned packaging. Yearbook of Agriculture 1986. 11 p.

Guðjón Þorkelsson. Impact of packing methods on the shelf life of ground beef. Yearbook of Agriculture 1986. 3 p.

1985:
Ólafur Reykdal, Guðjón Þorkelsson and others : Research on processed meat products. Fjölrit RALA nr.106, 1985, 137 bls.

Elín Hilmarsdóttir and Guðjón Þorkelsson: A study of cold cuts in lamb. Fjölrit RALA nr. 111, 1985, 28 p.

Guðjón Þorkelsson: Electrical stimulation of dilka carcasses. Report to the Agricultural Production Council. 1985, 35 p.

Guðjón Þorkelsson: Meat Research of the Food Department of RALA, Yearbook of Agriculture 1985, 14 pages.

1984:
Guðjón Þorkelsson: The effect of packaging on the freezing rate of lamb. Yearbook of Agriculture 1984, 8 pages.

1982:
Guðjón Þorkelsson: A study of ham. Yearbook of Agriculture 1982, 6 pages.

Guðjón Þorkelsson, Andrés Jóhannesson, Stefán Sch.Thorsteinsson and Stefán Aðalsteinsson. Cutting and slicing. Yearbook of Agriculture 1982, 7 pages.

1981:
Guðjón Þorkelsson, Andrés Jóhannesson, Stefán Sch. Thorsteinsson and Stefán Aðalsteinsson. Report to the Agricultural Production Council on cutting and slicing dill trays. 12 p. 1981.

1978:
Guðjón Þorkelsson, Stefán Aðalsteinsson, Jón Óttar Ragnarsson and Hannes Hafsteinsson. Meat Quality of Lambs in an Autunm Grazing Experiment. 12 p. The Annual Report of the Food Science Program 1978. Fjölrit RALA nr. 44

Stefan Aðalsteinsson, Guðjón Þorkelsson and Hannes Hafsteinsson. The Quality of Icelandic Smoked lamb and Mutton. A Comparison of Old and New Production Methods. 12 p. The Annual Report of the Food Science Program. 1978. Fjölrit RALA nr. 44.

1977:
Guðjón Þorkelsson. Training at the Meat Research Institute in Langford, Bristol, England. Annual Report of the Food Science Program 1977. 40 p. In the copy of RALA no. 17. 1977.

 
Articles in newspapers and magazines
Guðjón Þorkelsson. 2004. The handling of the raw material on board the ships is key. Ægir, 97 (6): 31.

Guðjón Þorkelsson. 2003. Seafood plus. Important for the fishing industry. Ægir. 96. 7th and 8th issues. p. 58-59.

Guðjón Þorkelsson, 2000. Further processing of fish, vocational education and research. Ægir. 93rd grade. Issue 6. June 2000. p. 32 - 35.

Ólafur Reykdal and Guðjón Þorkelsson. 1999. The value of fatty acids in food for agriculture. Freyr 8/99: 13-15.

Guðjón Þorkelsson, Stefán Sch. Thorsteinsson & Þyrí Valdi¬marsdóttir 1999. Lamb. Production system, composition, taste quality and consumer attitudes. Freyr 10: 28–33.

Guðjón Þorkelsson.1994 Production of beef. Quality issues. Frey. 90: 850-851.

Guðjón Þorkelsson: Weight loss of meat. Diet. Journal of food science students at the University of Iceland. 3 (1) 2 p.

Guðjón Þorkelsson, 1986 Research by RALA's food department on dilka meat. Freyr 82: 661-662.

Guðjón Þorkelsson: Product development in the meat industry. Diet. Publications of food science students.1986, 2 p.

 
Committee work and reports for the government

Guðjón Þorkelsson. 1997. Report on a new quality assessment of mutton. Report to the Minister of Agriculture.

Sigfús Jónsson, Halldór Árnason, Steingrímur Ari Arason, Vilhjálmur Lúðvíksson, Þorgeir Pálsson, Guðjón Þorkelsson and Þorbjörn Jónsson. Government support for business innovation. Committee on Innovation. Committee opinion, Ministry of Industry. 85 pp., 1993.

Guðjón Þorkelsson, Andrés Jóhannesson, Björn Björnsson, Gunnar Jónsson, Auðbjörn Kristinsson and Sigurður Einarsson: Revision of the assessment of beef, pork and horsemeat. Report to the Minister of Agriculture in July 1993, 20 pages.

Guðjón Þorkelsson 1989: Research on food from land and sea. Food and consumption. Reykjavík: Ministry of Health and Social Security, p. 188-195.

Guðjón Þorkelsson.1989: Domestic food production, agriculture. Food and consumption.

Reykjavík, Ministry of Health and Social Security, p. 171-178.


Teaching

Part-time lecturer at the Department of Chemistry 1978-1980,
Part-time teacher in the meat at the Reykjavík Vocational School 1981 - 1984.
Adjunct at H.Í from 1984 - 1987.
Appointed Associate Professor of Food Science in 50% work 1986-1988.
Assistant Professor of Food Science at 37% since 1988.