Investigation of effective compounds and antioxidant properties of five cultivar of hops (Humulus Lupulus L.) in different regions of Golestan province
Subject Areas : Medicinal Plants
mostafa hamidi
1
(gorgan university agricultural sciences & natural resources)
saeed navabpour
2
(Plant Breeding and Biotechnology Group, Faculty of Plant Production, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran)
mohsen fathi sadabadi
3
(Cotton Research Institute, Gorgan, Iran)
Keywords: Essential oil, Ecological conditions, content of phenolic, gas chromatograph, genetic factors,
Abstract :
To investigate the effect of the environment on phenolic and flavonoid contents and antioxidant and phytochemical properties of essential oils in five cultivars of hop, in four regions of Golestan province (Gorgan, Aliabad, Galikesh, and Azadshahr), an experiment was conducted as randomized complete block design with three replications during 2021-2022. Fruit extracts were prepared by soaking method using acetone solvent and the phenolic and flavonoid contents and the antioxidant properties were determined via Folin-Ciocalteu, aluminum chloride colorimetric, and DPPH method, respectively. Extraction of essential oils from fruit and identification of the compounds in the essential oil were carried out by water distillation method (Clevenger machine) and a gas chromatograph connected to a mass spectrometer (GC/MS), respectively. Overall, 32 compounds were identified, including Beta-acid, Alpha-acid, Co-humulone, total oil, Caryophyllene, Humulene, and Myrcene compounds, as the main components of the essential oil. Cascade cultivar in Gorgan region had the highest rate of phenolic and flavonoid contents as well as antioxidant activity, which can be related to the climatic conditions of the region and the higher potential of this cultivar. Also, all cultivars in Gorgan region had the highest content of secondary metabolites than others. Among the cultivated cultivars, Cascade and then Centennial had the highest content of secondary metabolites in all cultivation areas. Therefore, in order to achieve higher secondary metabolites, cultivation of Cascade in Gorgan region is recommend. On the other hand, Nugget in Galicash had the lowest content of secondary metabolites, which can be related to its lower potential in production of secondary metabolites and the climatic conditions of Galicash region which is located at a higher altitude and has a negative effect on the production of secondary metabolites. Therefore, considering the effect of different environmental conditions on the medicinal compounds of the species, it is recommended to evaluate the effect of the other factors, including the soil of the habitats.
Abdollahi, E., Khodaparast, M., Kiashi, F. and Hoormand, M. (2019). Role of medicinal herbs in the development of renal adverse effects: a review study. Journal of medicinal plants. 18:(4), 23-48.
Aberl, A., and Coelhan, M. (2012). Determination of volatile compounds in different Hop varieties by headspace-trap GC/MS in comparison with conventional hop essential oil analysis. Journal of agricultural and food chemistry. 60 (11): 2785- 2792.
Abiko, Y., Paudel, D. and Uehara, O. (2022). Hops components and oral health. Journal of Functional Foods. 92: 105035.
Acosta-Rangel, A., Rechcigl, J., Bollin, S., Deng, Z. and Agehara, S. (2021). Hop ('Humulus lupulus' L.) phenology, growth, and yield under subtropical climatic conditions: Effects of cultivars and crop management. Australian Journal of Crop Science. 15(5): 764-772.
Almeida, A.d.R., Maciel, M.V.d.O.B., Machado, M.H., Bazzo, G.C., de Armas, R.D., Vitorino, V.B., Vitali, L., Block, J.M. and Barreto, P.L.M. (2020). Bioactive compounds and antioxidant activities of brazilian hop (Humulus lupulus L.) extracts. Journal of Food Science Technology. 55, 340–347.
Arianfar, M., Akbarinodehi, D., Hemati, K. and Rostampoor, M. (2018). Effects of altitude and aspect on efficiency of producing essence and phytochemical properties of Artemisia aucheri Boiss and Artemisia sieberi Besser in South Khorasan rangelands. Journal of Rangeland. 3(12): 281-294.
Arruda, T. R., Pinheiro, P. F., Silva, P. I. and Bernardes, P. C. (2021). A new perspective of a well-recognized raw material: phenolic content, antioxidant and antimicrobial activities and α-and β-acids profile of brazilian hop (Humulus lupulus L.) extracts. LWT, 141, 110905.
Arvin, P. and Firouzeh, R. (2021). Study of phenolic and flavonoid compounds and essential oil content of medicinal plant of proveskia abrotanoides karel in three natural habitats of Raz and Jargalan County. Plant Process and Function. 11(47): 82-69.
Astray, G., Gullón, P., Gullón, B., Munekata, P. E. and Lorenzo, J. M. (2020). Humulus lupulus L. as a natural source of functional biomolecules. Applied Sciences. 10(15): 5074.
Babakhanzadeh Sajirani, E., Mousavizadeh, S.J. and Mozafari, KH. 2016. Phytochemical and antioxidant activity of Elaeagnus angustifolia L. fruits in different regions of Shahrood. Eco-phytochemical Journal of medicinal plants. 4(4): 62-73.
Blumenthal, M., Goldberg, A. and Brinckmann, J. (2000). Herbal medicine. expanded commission E monographs. USA: Integrative medicine communications; 2000.
Burits, M. and Bucar, F. (2000). Antioxidant activity of Nigella sativa essential oil. – Phytopathology. 14: 323-328.
Chang, Y.L., Kim, D.O., Lee, K.W., Lee, H.J. and Lee, C.Y. (2002). Vitamin C equivalent antioxidant capacity (VCEAC) of phenolic phytochemicals. Food Chemistry. 50(13): 3713-3717.
Dodds, K. (2017). Hops. A guide for new growers. NSW Department of Primary Industries. Australian Government.
Donner, P., Pokorný, J., Ježek, J., Krofta, K., Patzak, J. and Pulkrábek, J. (2020). Influence of weather conditions, irrigation and plant age on yield and alpha-acids content of Czech hop (Humulus lupulus L.) cultivars. Plant, Soil and Environment. 66(1): 41-46.
Fazeli-Nasab, B., Rahnama, M. and Mazaraie, A. (2017). Correlation between antioxidant activity and antibacterial activity of nine medicinal plant extracts. Mazandaran University of Medical Sciences. 27(149): 63-78.
Ghanbari, A., Moradi, H., Akbarzadeh, M. and Mohammadnejad Ganji, S. M. (2017). Quantity and quality of secondary metabolites in lavender plant under the influence of ecological factors. Nova Biologica Reperta. 4(2): 166-172.
Hakkinen, S.H. and Torronen, A.R. (2000). Content of flavonols and selected phenolic acids in strawberries and Vaccinium species: influence of cultivar, cultivation site and technique. Food Research Internation. 33: 517-24.
Hosseini, S.S., Nadjafi, F., Asareh, M.H. and Rezadoost, H. (2018). Morphological and yield related traits, essential oil and oil production of different landraces of black cumin (Nigella sativa) in Iran. Scientia Horticulturae. 233, 1-8.
Iglesias, A., Mitton, G., Szawarski, N., Cooleyc, H., Ramos, F., Meroi Arcerito, F., Brasescoab, C., Ramirez, C., Gendeab, L., Eguaras, M., Fanovich, A. and Maggi, M. (2020). Essential oils from Humulus lupulus as novel control agents against Varroa destructor. Industrial Crops and Products, 158:113043.
Khalili, M. and Ebrahimzadeh, M.A. (2014). a review on antioxidants and some of their common evaluation methods. Mazandaran University of Medical Sciences. 24(120): 188-208.
Khormali, A., Savadkohi, F., Oskoueiyan, R., Mehregan, I. and Mousavizadeh, S.J. (2020). Multivariate analysis of asparagus Antioxidant Properties in Relation to Environmental Factors. Journal of Vegetables Sciences. 4(7): 99-113.
Khoshsokhan, F., Babalar, M., Pourmeidani, A. and Fatahi, M.R. (2015). Antioxidant activity, total phenolics and oil content of some thymus kotschyanus and thymus daenensis populations. Plant products technology (Agricultural research). 15(1): 153-162.
Kobus-Cisowska, J., Szymanowska-Powałowska, D., Szczepaniak, O., Kmiecik, D., Przeor, M., Gramza-Michałowska, A., Cielecka-Piontek, J., Smuga-Kogut, M. and Szulc, P. (2019). Composition and in vitro effects of cultivars of Humulus lupulus L. hops on cholinesterase activity and microbial growth. Nutrients. 11, (6): 1377.
Krebs, C. (2019). Hops: A viable alternative crop for the Central/Southern Plains Crops and Soils. 52(4):4-6.
Lee, S.E., Hwang, H.J., Ha, J.S., Jeong, H.S. and Kim, J.H. (2012). Screening of medicinal plant extracts for antioxidant activity. Life Sciences, 73: 167-179.
Lyu, J. I., Ryu, J., Seo, K. S., Kang, K. Y., Park, S. H., Ha, T. H., Ahn, J. W. and Kang, S. Y. (2022). Comparative study on phenolic compounds and antioxidant activities of hop (Humulus lupulus L.) Strobile Extracts. Plants. 11(1), 135.
MacKinnon, D., Pavlovic, V., Ceh, B., Naglic, B. and Pavlovic, M. (2020). The impact of weather conditions on alpha-acid content in hop (Humulus lupulus L.) cv. Aurora. Plant, Soil and Environment. 66(10): 519-525.
Mafakheri, M., Kordrostami, M., Rahimi, M. and Matthews, P. D. (2020). Evaluating genetic diversity and structure of a wild hop (Humulus lupulus L.) germplasm using morphological and molecular characteristics. Euphytica. 216: 1-19.
Maliar, T., Nemecek, P., Urgeova, E., Maliarova, M., Nesvadba, V., Krofta, K., Vulganova, K., Kroslak, E. and Kraic, J., (2017). Secondary metabolites, antioxidant and anti-proteinase activities of methanolic extracts from cones of hop (Humulus lupulus L.) cultivars. Chemical Papers. 71(1), 41-48.
Marceddu, R., Carrubba, A. and Sarno, M. (2020). Cultivation trials of hop (Humulus lupulus L.) in semi-arid environments. Heliyon. 6(10): e05114.
Mazaraie, A. and Fahmideh, L. (2020). Evaluation of phytochemical and antioxidant activity of three widely-used medicinal plant in natural habitats of Fars province. Eco-phytochemical Journal of Medicinal Plants. 8(1): 90-105.
Mohammadnejad Ganji, S.M., Moradi, H., Ghanbari, A. and Akbarzadeh, M. (2017). Quantity and quality of secondary metabolites in lavender plant under the influence of ecological factors. Nova Biologica Reperta. 4: 166-172.
Molaie, M., Ardavan, M., Safidi, K., Bahrami, B. and Hashemi Majd, K. (2015). Ecological factors affecting the distribution of Artemisia aucheri Boiss. in the southeastern part of Sabalan. Scientific Journal of Rangeland. 11(2): 139-151.
Mozaffarian, V. (2018). Identification of medicinal and aromatic plants of Iran. Farhang Moasser publishing. Tehran. 114-115.
Najjar Firozjaee, M., Hemmati, KH. And Khorasaninejhad, S., Daraei Garmakhany, A. and Bagherifard, A. (2014). Effect of altitude on morphological and biochemical characteristics of nettle (Urtica Dioica L.) plant in mazandaran and golestan provinces. Journal of plant environmental physiology. 9(3): 1-11.
Ordone, A.A.L., Gomez, J.D. and Vattuone, M.A. (2008). Antioxidant activities of sechium edule swartz extracts. Food Chemistry. 97: 452-458.
Paventi, G., de Acutis, L., De Cristofaro, A., Pistillo, M., Germinara, G. S. and Rotundo, G. (2020). Biological activity of Humulus lupulus (L.) essential oil and its main components against Sitophilus granarius (L.). Biomolecules. 10(8): 1108.
Rajabi, Z., Ebrahimi, M., Farajpour, M., Mirza, M. and Ramshini, H. (2014). Compositions and yield variation of essential oils among and within nine Salvia species from various areas of Iran. Industrial Crops and Products. 61: 233 - 239.
Rossini, F., Virga, G., Loreti, P., Iacuzzi, N., Ruggeri, R. and Provenzano, M. E. (2021). Hops (Humulus lupulus L.) as a novel multipurpose crop for the Mediterranean region of Europe: Challenges and opportunities of their cultivation. Agriculture. 11(6): 484.
Rostaei, M., Fallah, S., Lorigooini, Z. and Surki, A.A. (2018). Crop productivity and chemical compositions of black Cumin essential oil in sole crop and intercropped with soybean under contrasting fertilization. Industrial Crops and Products. 125, 622-629.
Saboura, A., Ahmadi, A., Zeynali, A. and Parsa, M. (2014). Comparison between the contents of phenolic and flavonoid compounds and aerial part antioxidant activity in Scutellaria pinnatifida in two northIranian populations. Journal of medicinal plant and By-products. 13(3): 249-266.
Safi, Z., Saeidi, K., Lorigooini, Z. and Shirmardi, H. A. (2016). Evaluation of total phenols and antioxidant activity of mullein (Verbascum songaricum) ecotypes. Journal of Shahrekord University medicinal Science. 17 (6): 68-75.
Salanta, L., Tofana, M., Socaci, S., Mudura, E., Pop, C., Pop, A. and Farcas, A. (2015). Evaluation and comparison of aroma volatile compounds in hop varieties grown in romania. Romanian Biotechnological Letters. 20(6): 11049.
Stanius, Z., Dudėnas, M., Kaskoniene, V., Stankevicius, M., Skrzydlewska, E., Drevinskas, T., Ragazinskienė, O., Obelevicius, K. and Maruska, A. (2022). Analysis of the leaves and cones of lithuanian Hops (Humulus lupulus L.) varieties by chromatographic and spectrophotometric methods. Molecules. 27(9), 2705.
Vazquez Araujo, L., Rodriguez Solana, R., Cortes Dieguez, S. M. and Dominguez, J. M. (2013). Use of hydrodistillation and headspace solid‐phase microextraction to characterize the volatile composition of different hop cultivars. Journal of the Science of Food and Agriculture. 93, 2568-2574.
Woodske, D. (2012). Hop variety handbook. Createspace Independent Publishing Platform. 26-69.
Yan, D., Wong, Y. F., Tedone, L., Shellie, R. A., Marriott, P. J., Whittock, S. P. and Koutoulis, A. (2018). Chemotyping of new hop (Humulus lupulus L.) genotypes using comprehensive two-dimensional gas chromatography with quadrupole accurate mass time-of-flight mass spectrometry. Journal of Chromatography A, 1536, 110-121.
Zargoosh, Z., Ghavam, M. and Tavili, A. (2019). Comparison of antioxidant and total Phenol of scropholaria striata Boiss. In different weather conditions of Ilam province. Journal of Plant Research (Iranian Journal of Biology). 32(4): 759-768.
Zarinkamar, F. and Tajik, S. 2017. Evaluation of antioxidant activity and phenolic content from saffron organs (Crocus sativus L.). 8(2): 160-170.
Zugravu, C. A., Bohiltea, R. E., Salmen, T., Pogurschi, E. and Otelea, M. R. (2022). Antioxidants in Hops: bioavailability, health effects and perspectives for new products. antioxidants. 11(2): 241.
_||_Abdollahi, E., Khodaparast, M., Kiashi, F. and Hoormand, M. (2019). Role of medicinal herbs in the development of renal adverse effects: a review study. Journal of medicinal plants. 18:(4), 23-48.
Aberl, A., and Coelhan, M. (2012). Determination of volatile compounds in different Hop varieties by headspace-trap GC/MS in comparison with conventional hop essential oil analysis. Journal of agricultural and food chemistry. 60 (11): 2785- 2792.
Abiko, Y., Paudel, D. and Uehara, O. (2022). Hops components and oral health. Journal of Functional Foods. 92: 105035.
Acosta-Rangel, A., Rechcigl, J., Bollin, S., Deng, Z. and Agehara, S. (2021). Hop ('Humulus lupulus' L.) phenology, growth, and yield under subtropical climatic conditions: Effects of cultivars and crop management. Australian Journal of Crop Science. 15(5): 764-772.
Almeida, A.d.R., Maciel, M.V.d.O.B., Machado, M.H., Bazzo, G.C., de Armas, R.D., Vitorino, V.B., Vitali, L., Block, J.M. and Barreto, P.L.M. (2020). Bioactive compounds and antioxidant activities of brazilian hop (Humulus lupulus L.) extracts. Journal of Food Science Technology. 55, 340–347.
Arianfar, M., Akbarinodehi, D., Hemati, K. and Rostampoor, M. (2018). Effects of altitude and aspect on efficiency of producing essence and phytochemical properties of Artemisia aucheri Boiss and Artemisia sieberi Besser in South Khorasan rangelands. Journal of Rangeland. 3(12): 281-294.
Arruda, T. R., Pinheiro, P. F., Silva, P. I. and Bernardes, P. C. (2021). A new perspective of a well-recognized raw material: phenolic content, antioxidant and antimicrobial activities and α-and β-acids profile of brazilian hop (Humulus lupulus L.) extracts. LWT, 141, 110905.
Arvin, P. and Firouzeh, R. (2021). Study of phenolic and flavonoid compounds and essential oil content of medicinal plant of proveskia abrotanoides karel in three natural habitats of Raz and Jargalan County. Plant Process and Function. 11(47): 82-69.
Astray, G., Gullón, P., Gullón, B., Munekata, P. E. and Lorenzo, J. M. (2020). Humulus lupulus L. as a natural source of functional biomolecules. Applied Sciences. 10(15): 5074.
Babakhanzadeh Sajirani, E., Mousavizadeh, S.J. and Mozafari, KH. 2016. Phytochemical and antioxidant activity of Elaeagnus angustifolia L. fruits in different regions of Shahrood. Eco-phytochemical Journal of medicinal plants. 4(4): 62-73.
Blumenthal, M., Goldberg, A. and Brinckmann, J. (2000). Herbal medicine. expanded commission E monographs. USA: Integrative medicine communications; 2000.
Burits, M. and Bucar, F. (2000). Antioxidant activity of Nigella sativa essential oil. – Phytopathology. 14: 323-328.
Chang, Y.L., Kim, D.O., Lee, K.W., Lee, H.J. and Lee, C.Y. (2002). Vitamin C equivalent antioxidant capacity (VCEAC) of phenolic phytochemicals. Food Chemistry. 50(13): 3713-3717.
Dodds, K. (2017). Hops. A guide for new growers. NSW Department of Primary Industries. Australian Government.
Donner, P., Pokorný, J., Ježek, J., Krofta, K., Patzak, J. and Pulkrábek, J. (2020). Influence of weather conditions, irrigation and plant age on yield and alpha-acids content of Czech hop (Humulus lupulus L.) cultivars. Plant, Soil and Environment. 66(1): 41-46.
Fazeli-Nasab, B., Rahnama, M. and Mazaraie, A. (2017). Correlation between antioxidant activity and antibacterial activity of nine medicinal plant extracts. Mazandaran University of Medical Sciences. 27(149): 63-78.
Ghanbari, A., Moradi, H., Akbarzadeh, M. and Mohammadnejad Ganji, S. M. (2017). Quantity and quality of secondary metabolites in lavender plant under the influence of ecological factors. Nova Biologica Reperta. 4(2): 166-172.
Hakkinen, S.H. and Torronen, A.R. (2000). Content of flavonols and selected phenolic acids in strawberries and Vaccinium species: influence of cultivar, cultivation site and technique. Food Research Internation. 33: 517-24.
Hosseini, S.S., Nadjafi, F., Asareh, M.H. and Rezadoost, H. (2018). Morphological and yield related traits, essential oil and oil production of different landraces of black cumin (Nigella sativa) in Iran. Scientia Horticulturae. 233, 1-8.
Iglesias, A., Mitton, G., Szawarski, N., Cooleyc, H., Ramos, F., Meroi Arcerito, F., Brasescoab, C., Ramirez, C., Gendeab, L., Eguaras, M., Fanovich, A. and Maggi, M. (2020). Essential oils from Humulus lupulus as novel control agents against Varroa destructor. Industrial Crops and Products, 158:113043.
Khalili, M. and Ebrahimzadeh, M.A. (2014). a review on antioxidants and some of their common evaluation methods. Mazandaran University of Medical Sciences. 24(120): 188-208.
Khormali, A., Savadkohi, F., Oskoueiyan, R., Mehregan, I. and Mousavizadeh, S.J. (2020). Multivariate analysis of asparagus Antioxidant Properties in Relation to Environmental Factors. Journal of Vegetables Sciences. 4(7): 99-113.
Khoshsokhan, F., Babalar, M., Pourmeidani, A. and Fatahi, M.R. (2015). Antioxidant activity, total phenolics and oil content of some thymus kotschyanus and thymus daenensis populations. Plant products technology (Agricultural research). 15(1): 153-162.
Kobus-Cisowska, J., Szymanowska-Powałowska, D., Szczepaniak, O., Kmiecik, D., Przeor, M., Gramza-Michałowska, A., Cielecka-Piontek, J., Smuga-Kogut, M. and Szulc, P. (2019). Composition and in vitro effects of cultivars of Humulus lupulus L. hops on cholinesterase activity and microbial growth. Nutrients. 11, (6): 1377.
Krebs, C. (2019). Hops: A viable alternative crop for the Central/Southern Plains Crops and Soils. 52(4):4-6.
Lee, S.E., Hwang, H.J., Ha, J.S., Jeong, H.S. and Kim, J.H. (2012). Screening of medicinal plant extracts for antioxidant activity. Life Sciences, 73: 167-179.
Lyu, J. I., Ryu, J., Seo, K. S., Kang, K. Y., Park, S. H., Ha, T. H., Ahn, J. W. and Kang, S. Y. (2022). Comparative study on phenolic compounds and antioxidant activities of hop (Humulus lupulus L.) Strobile Extracts. Plants. 11(1), 135.
MacKinnon, D., Pavlovic, V., Ceh, B., Naglic, B. and Pavlovic, M. (2020). The impact of weather conditions on alpha-acid content in hop (Humulus lupulus L.) cv. Aurora. Plant, Soil and Environment. 66(10): 519-525.
Mafakheri, M., Kordrostami, M., Rahimi, M. and Matthews, P. D. (2020). Evaluating genetic diversity and structure of a wild hop (Humulus lupulus L.) germplasm using morphological and molecular characteristics. Euphytica. 216: 1-19.
Maliar, T., Nemecek, P., Urgeova, E., Maliarova, M., Nesvadba, V., Krofta, K., Vulganova, K., Kroslak, E. and Kraic, J., (2017). Secondary metabolites, antioxidant and anti-proteinase activities of methanolic extracts from cones of hop (Humulus lupulus L.) cultivars. Chemical Papers. 71(1), 41-48.
Marceddu, R., Carrubba, A. and Sarno, M. (2020). Cultivation trials of hop (Humulus lupulus L.) in semi-arid environments. Heliyon. 6(10): e05114.
Mazaraie, A. and Fahmideh, L. (2020). Evaluation of phytochemical and antioxidant activity of three widely-used medicinal plant in natural habitats of Fars province. Eco-phytochemical Journal of Medicinal Plants. 8(1): 90-105.
Mohammadnejad Ganji, S.M., Moradi, H., Ghanbari, A. and Akbarzadeh, M. (2017). Quantity and quality of secondary metabolites in lavender plant under the influence of ecological factors. Nova Biologica Reperta. 4: 166-172.
Molaie, M., Ardavan, M., Safidi, K., Bahrami, B. and Hashemi Majd, K. (2015). Ecological factors affecting the distribution of Artemisia aucheri Boiss. in the southeastern part of Sabalan. Scientific Journal of Rangeland. 11(2): 139-151.
Mozaffarian, V. (2018). Identification of medicinal and aromatic plants of Iran. Farhang Moasser publishing. Tehran. 114-115.
Najjar Firozjaee, M., Hemmati, KH. And Khorasaninejhad, S., Daraei Garmakhany, A. and Bagherifard, A. (2014). Effect of altitude on morphological and biochemical characteristics of nettle (Urtica Dioica L.) plant in mazandaran and golestan provinces. Journal of plant environmental physiology. 9(3): 1-11.
Ordone, A.A.L., Gomez, J.D. and Vattuone, M.A. (2008). Antioxidant activities of sechium edule swartz extracts. Food Chemistry. 97: 452-458.
Paventi, G., de Acutis, L., De Cristofaro, A., Pistillo, M., Germinara, G. S. and Rotundo, G. (2020). Biological activity of Humulus lupulus (L.) essential oil and its main components against Sitophilus granarius (L.). Biomolecules. 10(8): 1108.
Rajabi, Z., Ebrahimi, M., Farajpour, M., Mirza, M. and Ramshini, H. (2014). Compositions and yield variation of essential oils among and within nine Salvia species from various areas of Iran. Industrial Crops and Products. 61: 233 - 239.
Rossini, F., Virga, G., Loreti, P., Iacuzzi, N., Ruggeri, R. and Provenzano, M. E. (2021). Hops (Humulus lupulus L.) as a novel multipurpose crop for the Mediterranean region of Europe: Challenges and opportunities of their cultivation. Agriculture. 11(6): 484.
Rostaei, M., Fallah, S., Lorigooini, Z. and Surki, A.A. (2018). Crop productivity and chemical compositions of black Cumin essential oil in sole crop and intercropped with soybean under contrasting fertilization. Industrial Crops and Products. 125, 622-629.
Saboura, A., Ahmadi, A., Zeynali, A. and Parsa, M. (2014). Comparison between the contents of phenolic and flavonoid compounds and aerial part antioxidant activity in Scutellaria pinnatifida in two northIranian populations. Journal of medicinal plant and By-products. 13(3): 249-266.
Safi, Z., Saeidi, K., Lorigooini, Z. and Shirmardi, H. A. (2016). Evaluation of total phenols and antioxidant activity of mullein (Verbascum songaricum) ecotypes. Journal of Shahrekord University medicinal Science. 17 (6): 68-75.
Salanta, L., Tofana, M., Socaci, S., Mudura, E., Pop, C., Pop, A. and Farcas, A. (2015). Evaluation and comparison of aroma volatile compounds in hop varieties grown in romania. Romanian Biotechnological Letters. 20(6): 11049.
Stanius, Z., Dudėnas, M., Kaskoniene, V., Stankevicius, M., Skrzydlewska, E., Drevinskas, T., Ragazinskienė, O., Obelevicius, K. and Maruska, A. (2022). Analysis of the leaves and cones of lithuanian Hops (Humulus lupulus L.) varieties by chromatographic and spectrophotometric methods. Molecules. 27(9), 2705.
Vazquez Araujo, L., Rodriguez Solana, R., Cortes Dieguez, S. M. and Dominguez, J. M. (2013). Use of hydrodistillation and headspace solid‐phase microextraction to characterize the volatile composition of different hop cultivars. Journal of the Science of Food and Agriculture. 93, 2568-2574.
Woodske, D. (2012). Hop variety handbook. Createspace Independent Publishing Platform. 26-69.
Yan, D., Wong, Y. F., Tedone, L., Shellie, R. A., Marriott, P. J., Whittock, S. P. and Koutoulis, A. (2018). Chemotyping of new hop (Humulus lupulus L.) genotypes using comprehensive two-dimensional gas chromatography with quadrupole accurate mass time-of-flight mass spectrometry. Journal of Chromatography A, 1536, 110-121.
Zargoosh, Z., Ghavam, M. and Tavili, A. (2019). Comparison of antioxidant and total Phenol of scropholaria striata Boiss. In different weather conditions of Ilam province. Journal of Plant Research (Iranian Journal of Biology). 32(4): 759-768.
Zarinkamar, F. and Tajik, S. 2017. Evaluation of antioxidant activity and phenolic content from saffron organs (Crocus sativus L.). 8(2): 160-170.
Zugravu, C. A., Bohiltea, R. E., Salmen, T., Pogurschi, E. and Otelea, M. R. (2022). Antioxidants in Hops: bioavailability, health effects and perspectives for new products. antioxidants. 11(2): 241.
