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The Nigerian economy depended mainly on crude oil during the era of oil boom of 1973 which lasted up till1983. Agriculture was grossly neglected by successive governments. Following the economic recession that occurred years after and due to fall in crude oil price, the Nigerian government began to advocate for economic diversification. Consequently, agriculture became the area of interest and priority for industrial raw material sources. Unfortunately, Nigeria had imbibed the tradition of importing raw materials for all her industrial productions thereby creating unfavourable balance of trade between Nigeria and her foreign trading partners thus resulting in increase in the prices of finished products. Beer production is not exempted from the price increase since its raw materials are equally imported with their attendant problems on Nigeria’s foreign exchange. One of such raw materials is hops. The hop (Humulus lupulus L.) is a perennial dioecious climbing plant of hemp (cannabis) family and belonging to the order (urticales) which are grown in the temperate regions of the world, solely to meet the demand of the brewing industry. Hop extracts give beer its bitter taste, improve foam stability and act as antiseptics towards microorganisms. The quest to substitute hops with some tropical bitter vegetables in Nigeria’s brewing industry dates back to 1983 and since that time, many have compared hop extracts with those of Nigerian bitter plants such as Garcinia kola, Azadirachta indica, Vernonia amygdalina and Gongronema latifolium. This review takes a critical look on the efforts made so far since 1983 in investigating the potentiality of using Nigerian bitter plant extracts as suitable substitute for those of hop in the Nigerian brewing industry with special emphasis on Gas Chromatography Mass–Spectrometry (GC–MS) and Gas Chromatography–Flame Ionization Detector (GC–FID) techniques. It was concluded that none of the Nigerian plants has perfect potential as suitable substitute for hops in the Nigerian brewing industry. Consequently, further research efforts in the area of mixtures/blends of extract of plant species which mimic hop taste is strongly recommended.
Okafor N. Modern Industrial Microbiology and Biotechnology: Enfield (NH). Science Publishers; 2007.
Hough JS, Briggs DE, Stevens R, Young TW. Malting and Brewing Science, Vol. 2, 2nd ed., Chapman and Hall, London, England; 1982:389-452.
Burgess AH. Hops, Botany, Cultivation and Utilization, Leonard Hill, London. 1964: 300.
Peacock V. Hop Chemistry 101. SE Regional MBAA. 2009:35(1).
Hudson JR. The institute of brewing analysis committee current outlook on malt analysis. J. Inst. Brewing.1976;82(4):226-227.
Westwood K. Hop products and their effect on bittering quality. Brewers’ Guardian. 1994;123(12).
De Keukeleire D. Fundamentals of beer and hop chemistry. Quimica Nova. 2000; 23(1):108-112
Micheal M. Beer and its drinkers: an ancient near eastern love story. Near Eastern Archaeology. 2004;67(2):84-95.
Nelson M. The barbarian’s beverage: a history of beer in ancient Europe. Abingdon, Oxon: Routledge Press; 2005.
Arnold J. Origin and History of Beer and Brewing: From Prehistoric Times to the Beginning of Brewing Science and Technology: Cleveland, Ohio: Thieme Publishers; 2005.
Elzinga K. Beer: The structure of american industry, edited by walter adama and james brock. Upper Saddle River, New Jessey: Pearson Hall; 2005.
Badmus L. Beer and the nation’s economy – The Nigerian Telegraph; 2013. Available:http://telegraphing.com/2013/II/beer-nations-economy Retrieved 25-10-2014.
Kohombange S, Rajapaksha RGAS, Rathnasekara N. Effects of foliar application of beer (ethanol) on the growth, flowering and fruit setting of bitter gourd (Momordica charantia L.) plants. International Journal of Research. 2019; 6(1):501-505.
Buzrul S, Alpas H, Bozoglu F. Effect of high hydrostatic pressure on quality parameters of lager beer. Journal of the Science of Food and Agriculture. 2005;85: 1672-1676.
Grants HL. The practical brewer. Master brewers’ association of the Americans. Impressions Inc. Madison, Wisconson. 1977:128-146.
European Brewery Convention: Analytica – EBC, 3rd Edn., Schweizer Brauerei-Rundschau, Zurich; 1975.
American Society of Brewing Chemists. Methods of Analysis, 7th Edn., American Society of Brewing Chemists, St. Paul, Minesota; 1976.
Institute of Brewing. Recommended Methods of Analysis. The Institute of Brewing, London; 1977.
Fix G. Beer foam and CO2 levels. The New Brewer. 1989;6(2).
Meilgaurrd MC, Peppard TL. The Flavour of beer, In: Morton, I.D. and Maclead, A.J. (eds.). Food flavours, Part B. The flavor of Beverages, Elsevier, New York; 1986.
De Clerck JX. A Textbook of Brewing Volume 1, Translated by K. Barton- Wright. London: Chapman-Hall Ltd; 1986.
McWilliam IC. A survey of the antibiotic powers of yeasts. J. Gen. Microbiol. 1959; 21:410-414.
Bamforth. CW. Progress in brewing science and beer production. Annual Review of Chemical and Biomolecular Engineering. 2017;8:161-176.
Zurcher C, Kursawe R. European Brewery Convention Proceedings of the 14th Congress, Salzburg. 1973;445.
Langstaff SA, Lewis MJ. The mouth feel of beer – a review. J. Inst. Brew. 1993;99:31-37.
Carroll TCN. Technical Quarterly of the Master Brewers Association of the Americas. 1979;16:116.
Wainwright T. Biochemistry of Brewing: Modern Brewing Technology, edited by W.P.K. Findlay. Cleveland, Ohio. The Macmillan Press; 1971.
Kraus-Weyerman T. pH in the Brewery, A much underestimated Brewing Variable. 1998;1-30.
Moncrieff RW. The Chemical Senses, 3rd edn. Leonard Hill, London; 1967.
Schuina GL, Quelhas JOF, Castilhos MBM, Carvalho, GBM, Del Blanchi VL. Alternative produc tion of craft lager beers using artichoke (Cynara scilymus L.) as a hops substitute. Food Sci. Technol, Campinas. 2020;40(1):157-161.
Okafor N, Anichie G. West African hop substitute for sorghum lager. Brewing and Distillation International. 1983;13:20-21.
Adenuga W, Olaleye ON, Adepoju PA. Utilization of bitter vegetable leaves (Gongronema latifolium, Vernonia amygdalina and Garcinia kola) extracts as substitute for hops in sourghum beer production. African Journal of Biotechnology. 2010;9(51):8819-8823.
Aniche GN, Uwakwe GU. Potential use of Garcinia kola as hop substitute in lager beer brewing. World Journal of Microbiology and Biotechnology. 1990; 6(3):323-327.
Ajebesone PE, Aina JO. Potential African substitutes for hops in tropical beer brewing. J. Food Technol., in Afr. 2004; 9(1):13-16.
Okafor VN, Okafor UW, Ezem SN. Metabolites composition of Garcinia kola extract as potential substitute for isomerized hop extract in beer brewing. Chemistry Research Journal. 2017;2(5): 153-162.
Okafor VN. Hops and Potential Nigerian Substitutes: Comparative Studies in Beer Brewing, Lambert Academic Publishing- GmbH & Co. KG, Germany, ISBN-10 (9783330014817); 2016.
Okafor VN, Eboatu AN. Anyalebechi RI, Okafor UW. Comparative studies of the physicochemical properties of beers brewed with hop extracts and extracts from four selected tropical plants. Journal of Advanced Chemical Sciences. 2016;2(4): 282-286.
Okafor VN, Obodoeze JJ. Comparative evaluation of phytochemical constituents, bitterness characters and essential oil contents of extracts from four Nigerian plants as potential substitutes for isomerized hop extract in beer brewing. Chemistry Research Journal. 2017;2(4): 16-21.
Eboatu AN, Ejike EN, Okafor VN. Evaluation of anti-nutritional factors in hop extracts and extract from Azadirachta indica as potential substitute in the Nigerian beer industry. International Journal of Pharmaceutical, Chemical and Biological Sciences. 2016;1(10):1-14.
Okafor VN, Eboatu AN, Omuku PE. Comparative studies of bitterness, phytochemical and mineral contents of hop extracts and extracts from four selected tropical plants: Asian Journal of Medical and Health Research. 2016;1(6):1-15.
Okafor VN, Anyalebechi, RI, Okafor UW. Characterization of hop extracts and extracts from some selected Nigerian plants by GC/MS and brewing qualities analyses: International Journal of Research and Development. 2016;2(9):9-64.
Okafor VN. Spectroscopic methods for evaluation of hop extracts and extract from Gongronema latifolium as substitute in the Nigerian beer industry. International Journal of Advanced Research. 2016; 4(12):2499-2504.
Okafor VN, Uche UB, Abailim RC. Levels of polycyclic aromatic hydrocarbons (PAHs) in beers: consumption and public health concerns. Chemical Science International Journal. 2020;29(1):47-49.
Okafor VN, Okafor UW, Anyalebechi IR. Gas chromatography-mass spectrometry (GC-MS) profiling of hops and some Nigerian potential hop substitutes: comparative studies in beer brewing. Journal of Chromatography and Separation Techniques. 2020;11(2),art. 429:1-9.
Okafor VN, Anyalebechi IR, Okafor UW, Okonkwo, CP, Obiefuna, JN, Obiadi, MC. Phytochemical constituents of extracts of hops and some potential Nigerian hop substitutes: a comparative study in beer brewing. International Journal of Biological and Chemical Research. 2020;1(1):1-7.
Terashima K, Takaya Y, Niwa M. Powerful antioxidative agents based on garcinoic acid from Garcinia kola.Bio-organic Med. Chem. 2002;10(5):1619-1625.
Iwu MM, Igboko OA, Okunji CO, Tempesta MS. Antidiabetic and aldose reductase activities of biflavanones of Garcinia kola. J. Pharm. Pharmacol. 1990;42.290-292.
Braide VP. Anthihepatotoxic biochemical effects of kola viron, a bifkvonoid of Garcinia kola seeds. Phytotheraphy Res. 1991;5:35-37.
Buttler, GW; Bailey, RW. Chemistry and Biochemistry of herbage. Academic Press, London and New York; 1973.
Adesuyi AO, Elumm IK. Adaramola FB. Nutritional and phytochemical screening of Garcinia kola. Advanced Journal of Food Science and Technology. 2012;4(1):9-14.
Mabberley DJ. Azadirachta. In: Flora malesiana Ser. Spermtophyta. 1995;12(1): 1-407.
Onwuka CFI, Akinsoyinu AO, Tewe OO. Feed value of some Nigerian browse plant: chemical composition and in vitro digestibility. East African Agricultural and Forestry Journal. 1989;54:157-163.
Fayemi AA. The processing and preservation of bitter leaf (Vernonia amygdalina). M.Sc. thesis in the Department of Food Technology University of Ibadan, Nigeria; 1982.
Okolie UV, Okeke CE, Oli JM, Ehiemere IO. Hypogly caemic indices of Vemonia amygdalina on postpaandial blood glycose concentration of healthy humans. African Journal of Biotechnology. 2008;7(24):481-4585.
Dike MC. Proximate, phytochemical and nutrient compositions of some fruits, seeds, and leaves of some plant species at Umudike, Nigeria. ARPN Journal of Agricultural and Biological Sciences. 2010; 5(1):7-16.
Emeka EJI, Obiora O. Effect of long term consumption of a diet supplemented with leaves of Gongronema latifolium barth on some biochemical and histological parameters in male albino rats. Journal of Biological Sciences. 2009;9(8):859-865.
Nwanjo HU, Alumanah EO. Effect of aqueous extract of Gongronema latifolium on some indices of liver function in rats. Global Journal of Medical Sciences. 2006; 5(1):17-20.
Oliver-Bever B. Mechanical Plants in Tropical West Africa. Cambridge University Press, Cambridge, United Kingdom. 1986; 375.
Shellie RA., Poynter SDH, Li J, Gathercole JL, Whittock SP, Koutoulis A. Varietal characterization of hop (Humulus lupulus L.) by GC-MS analysis of hop cone extracts. J. Sep. Sci. 2009;32:3720-3725.
Fernie AR, Schauer N. Metabolomics assisted breeding: a viable option for crop improvement? Trends Genet. 2008;25:39-48.
Finar IL. Organic Chemistry Volume 2: Stereochemistry and the Chemistry of Natural Products. Fifth Edition. Pearson Education, Ltd. Pataparganj, Delhi, India; 1975.
Christian GD. Analytical Chemistry. Sixth Edition, John Wiley and Sons, Danoyagani, New Delhi; 2004.
EPA Test Method 8100: Polycyclic hydrocarbons. 1986:10.
SW-846 Test Method 3550: Polycyclic hydrocarbons. 1982:7.
Anyakorah C, Ogbeche A, Palmer P, Coker H, Ogah C. GC/MS analysis of polynuclear aromatic hydrocarbons in sediment samples from the Niger-Delta region. Chemosphere. 2005;60:990-997.
Nduka JK, Orisakwe OE. Water quality issues in the Niger Delta of Nigeria: polyaromatic and straight chain hydrocarbons in some selected surface waters. Water Quality, Exposure and Health. 2010;2:65-74.
Garcia-Falcon MS, Simal-Gandara J. Determination of PAHs in alcoholic drinks and identification of their potential sources. Food Additives and Contaminants. 2005;22 (9):791-797.
Nduka JK, Anyakora C, Obi E, Obumselu FO, Ezenwa TE, Ngozi- Olehi. Polyaromatic hydrocarbons and inorganic contaminants at refuse dumpsites in Awka, South Eastern Nigeria: A public health implication. Journal of Scientific Research and Report. 2013;2(1): 173-189.