Hop wax has been found to occur in beer and is present in concentrations of 0-5-0-6 p.p.m. The wax occurs in the non-steam volatile fraction of the neutral ether solubles of beer. A number of acids produced by saponiflcation of hop wax have been shown also to occur as volatile constituents of beer. The particular sample of hop wax used is shown to have very little effect on the rate of deterioration of a acids. Certain aspects of the photoisomerization of humulone and humulone-hop wax combinations are discussed.
The sesquiterpenes caryophyilene, humulene, isocaryophyilene and “farnesene” have been found to occur in beer. These sesquiterpenes occur in conjunction with myrcene, methylnonyl ketone and other unidentified hop oil constituents.
Eighty-one volatile acids have been detected in the sodium bicarbonate solubles of an ethereal extract of beer, and they together account for 65% of the total ethersoluble acids. Acids positively identified are methanoic (formic), ethanoic (acetic), n-propanoic (propionk), n-butanoic (butyric), 3-methylpropanok (/sobutyric), n-pentanoic (n-valeric), 3-methylbutanoic (fsovalerk), n-hexanoic (caproic), hex-2-enoic, hex-3-enoic, n-octanoic (caprylic), n-nonanoic (pelargonic), n-decanoic (capric), n-dodecanoic (lauric), n-tetradecanoic (myristic), n-hexadecanoic (palmitic), noctadecanoic (stearic), n-octadec-9-enoic (oleic), n-octadec-9.l2-dienoic (linoleic), n-octadec-9.l2J5-trienoic (linolenic), n-docosanoic (behenic) and n-hexacosanoic (cerotic or cerotinic) acids. Crystalline ethane-l.2-dicarboxylic (succinic) acid was also isolated. Total ether-soluble acids isolated were found in beer at a concentra tion level of 125 p.p.m. compared with 67 p.p.m. for hopped wort and 61 p.p.m. for sweet wort. All volatile acids present in hopped wort were found to be present also in sweet wort, and in only slightly different proportions. Further, all volatile acids present in beer were found in hopped wort, though relative proportions differed.
Fusel oil components found in beer include methanol, n‐propanol, isopropanol, n‐butanol, sec‐butanol, isobutanol, 2‐methyl butanol, 3‐methyl butanol, ethyl acetate, sec‐butyl acetate, isobutyl acetate and isoamyl acetate. A refined isolation procedure has allowed the recognition of a number of hop oil constituents in beer apart from those previously reported. In addition, several of the volatile substances which occur in beer have been shown to originate from malt and to occur in the essential oil of barley and malt husk. Hop oil, malt husk oil and identified fusel oil components together account for all but seven of fifty neutral steam‐volatile ether‐soluble constituents of beer so far detected.
A simple microdiffusion procedure is described for the determination of acetaldehyde in beer, whereby the acetaldehyde content of the beer sample in the outer chamber of a Conway unit is absorbed in a semicarbazide solution and the optical density of the product is measured at 224 mμ. The estimation is not specific for acetaldehyde, as it in fact determines total volatile carbonyl compounds. A colorimetric estimation is also described.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.