Characterisation of hop varieties grown in Romania based on their contents of bitter acids by HPLC in combination with chemometrics approach
L.C. Salanţă, M. Tofană, S. Socaci, E. Mudura, A. Fărcaş, C. Pop, A. Pop, A. Odagiuhttps://doi.org/10.17221/365/2014-CJFSCitation:Salanţă L.C., Tofană M., Socaci S., Mudura E., Fărcaş A., Pop C., Pop A., Odagiu A. (2015): Characterisation of hop varieties grown in Romania based on their contents of bitter acids by HPLC in combination with chemometrics approach. Czech J. Food Sci., 33: 148-155.
Reverse-phase high performance liquid chromatography technique was used for studying the evolution of bitter acids from three varieties of hop growing in Romania during the development of hop cones and the pelletisation process in order to provide the information on the bitter acids profile of each cultivar. Chemometrics methods were applied for highlighting the statistical correlations existing between the genotype (variety), chemotype (composition), and phenotype (phenophase of cone development) with respect to the classes of biologically active compounds investigated (bitter acids). The bitter acid content of each hop cultivar was not only significantly dependent on the phenophases of the cones, but was also influenced by the harvest year. The variations in the α/β ratio as well as cohumulone and colupulone contents were low in both experimental years and the cohumulone/∑α did fraction not exceed 30% in any of the three varieties.Keywords:α-acids; β-acids; Romanian hop cultivars; Humulus lupulus; principal component analysisReferences:
Anonymous (2006): Analytica EBC (Analityca European Brewery Convention). Methods 7.2, 7.4, 7.7. 6th Ed. Nürnberg, Verlag Hans Carl Getränke-Fachverlag.Beatson R. A., Ansell K. A., Graham L. T. (2003): Breeding, development, and characteristics of the hop ( Humulus lupulus ) cultivar ‘Nelson Sauvin’. New Zealand Journal of Crop and Horticultural Science, 31, 303-309 https://doi.org/10.1080/01140671.2003.9514265Česlová Lenka, Holčapek Michal, Fidler Martin, Drštičková Jitka, Lísa Miroslav (2009): Characterization of prenylflavonoids and hop bitter acids in various classes of Czech beers and hop extracts using high-performance liquid chromatography–mass spectrometry. Journal of Chromatography A, 1216, 7249-7257 https://doi.org/10.1016/j.chroma.2009.09.022De Cooman L., Everaert E., De Keukeleire D. (1998): Quantitative analysis of hop acids, essential oils and flavonoids as a clue to the identification of hop varieties. Phytochemical Analysis, 9, 145-150 https://doi.org/10.1002/(SICI)1099-1565(199805/06)9:3<145::AID-PCA393>3.0.CO;2-KGad Haidy A., El-Ahmady Sherweit H., Abou-Shoer Mohamed I., Al-Azizi Mohamed M. (2013): Application of Chemometrics in Authentication of Herbal Medicines: A Review. Phytochemical Analysis, 24, 1-24 https://doi.org/10.1002/pca.2378Gerhäuser Clarissa (2005): Beer constituents as potential cancer chemopreventive agents. European Journal of Cancer, 41, 1941-1954 https://doi.org/10.1016/j.ejca.2005.04.012Hoek Arie C., Hermans-Lokkerbol Ank C. J., Verpoorte Robert (2001): An improved NMR method for the quantification of ?-Acids in hops and hop products. Phytochemical Analysis, 12, 53-57 https://doi.org/10.1002/1099-1565(200101/02)12:1<53::AID-PCA550>3.0.CO;2-EJaskula Barbara, Goiris Koen, De Rouck Gert, Aerts Guido, De Cooman Luc (2007): Enhanced Quantitative Extraction and HPLC Determination of Hop and Beer Bitter Acids. Journal of the Institute of Brewing, 113, 381-390 https://doi.org/10.1002/j.2050-0416.2007.tb00765.xJelínek L., Šneberger M., Karabín M., Dostálek P. (2010): Comparison of Czech hop cultivars based on their contents of secondary metabolites. Czech Journal of Food Sciences, 28: 309–316.Khatib Alfi, Wilson Erica G., Kim Hye Kyong, Supardi Moses, Choi Young Hae, Verpoorte Robert (2007): NMR assignment of iso-α-acids from isomerised extracts ofHumulus lupulus L. cones. Phytochemical Analysis, 18, 371-377 https://doi.org/10.1002/pca.991Krofta K. (2003): Comparison of quality parameters of Czech and foreign hop varieties. Plant, Soil and Environment, 49: 261–268.Lorenzana A., Hermoso de Mendoza A., Seco M.V., Casquero P.A. (2010): Population development of Phorodon humuli and predators (Orius spp.) within hop cones: Influence of aphid density on hop quality. Crop Protection, 29, 832-837 https://doi.org/10.1016/j.cropro.2010.04.014Mitter W., Steiner S.H., Hopfen G.M., Mainburg B.H. (2009): Annual fluctuations in hop quality – options for adjustment in the brewhouse. Brauwelt International, 2009/I: 36–37.Negri G., Santi D., Tabach R. (2010). Bitter acids from hydroethanolic extracts of Humulus lupulus L., Cannabaceae, used as anxiolytic. Revista Brasileira de Farmacognosia Brazilian Journal of Pharmacognosy, 20: 850–859.Patzak Josef, Nesvadba Vladimír, Henychová Alena, Krofta Karel (2010): Assessment of the genetic diversity of wild hops (Humulus lupulus L.) in Europe using chemical and molecular analyses. Biochemical Systematics and Ecology, 38, 136-145 https://doi.org/10.1016/j.bse.2009.12.023Salanţă L.C., Tofană M., Socaci S., Mudura E., Fărcaş A. (2013): The internal validation of HPLC and conductometric method for the determination of hop bitter acids. Journal of Agroalimentary Processes and Technologies, 19: 362–366.Sahlstrom A., Rostad S. (2011): HPLC determination of α- and β-acids in hops. Concordia College Journal of Analytical Chemistry, 2: 78–83.Shellie Robert A., Poynter Samuel D. H., Li Jianfeng, Gathercole Jessica L., Whittock Simon P., Koutoulis Anthony (2009): Varietal characterization of hop ( Humulus lupulus L.) by GCâMS analysis of hop cone extracts. Journal of Separation Science, 32, 3720-3725 https://doi.org/10.1002/jssc.200900422Srečec S., Zechner-Krpan V., Petravić-Tominac V., Čerenak A., Liber Z., Šatović Z. (2010): Phenotypic and alpha-acid content diversity of wild hop populations in Croatia. Plant, Soil and Environment, 56: 37–42.Tofană M., Mora A., Socaci S., Muste S., Mudura E., Michiu D., Salanţă L., Fărcaş A. (2012): The content in alpha bitter acids of hop cultivars cultivated in Romania during 2008–2011. Hop and Medicinal Plants, 20: 23–28.Tofană M. (2006): Substanţe amare şi de aromă din hamei. Cluj-Napoca, Ed. Alma Mater: 23–24.Van Cleemput Marjan, Cattoor Ko, De Bosscher Karolien, Haegeman Guy, De Keukeleire Denis, Heyerick Arne (2009): Hop ( Humulus lupulus )-Derived Bitter Acids as Multipotent Bioactive Compounds. Journal of Natural Products, 72, 1220-1230 https://doi.org/10.1021/np800740mZhang Xiaozhe, Liang Xinmiao, Xiao Hongbin, Xu Qing (2004): Direct characterization of bitter acids in a crude hop extract by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry. Journal of the American Society for Mass Spectrometry, 15, 180-187 https://doi.org/10.1016/j.jasms.2003.09.014