Comparison of Volatile Flavor Compounds in Ethiopian Alcoholic Beers
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Date
2018-03
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Addis Ababa University
Abstract
The objective of this study was to compare the level of Oavor compounds of Edllopian alcoholic
beers In additIon, the knowledge, attitude and practice (KAP) study was employed to assess dIe
level ofllllderstanding ofprofessio11als working in breweries about the Oavor compounds related
to beer quality and safety. A total of 220 beer samples fiom 11 brands were collected randomly
fiom diffi:rent relall oudets and fOod markets aClOSS ten sub-citIes of AddlS Ababa. For each
brand, two beers WCle J"lJ1Jdomly collected nOllJ each sub city. For analysis, two composile
samples were plepared by taking 20 ml fiom tile 330 ml beer bottle and each brafld were
aflalyzed lil quadmplicate. VDKs were analyzed with HS-GC-ECD method, wIllIe Acetaldehyde,
Esters, Dimethyl sulfide (DMS) alld highCl· alcohols wele analyzed with HS-GC-FID method A
stnJctwed questI01lf1alIe was used to Ulldeltake KAP study One-way ANOVA WCle used to
evaluate the sigJlJljcance diffClC1Jce betweCll bJ"lmds at the 005 level of sigl11ficance and DUllcan
HSD was used to sepamte the means. VolatIle Oavor compounds were detected in this studY,11ld
they were 01 the range between (13.8-128.2 fig1) for total vicimil diketolles,(l. 65-8.0 mg/l) for
Acetaldehyde,(O 00-7635 fig1) for DMS, (11. 75- 28.35 mg/l) for Ethyl acetate,(8. 40-2095 mg/l)
fOr n-Propanol,(5. 85-177 mg/l) fOr Iso-butanol, (0 IO-3. 95 mg/l) for Isoamyl acetate and (38. 05-
650 mg/l) fOr Amyl alcohol Tills means the total VDK content of dllee brand~ of beers were
above the dneshoId value and oJJly two braflds have acetaldehyde COllcelltratIon above dIe
threshold value. In olle brand, DMS lS not detected and duee bJ"llllds were above the dlleshold
value. For Iso-amaylacetate, tCll brands were above the dlfeshold value. Conversely, the bigber
alcohols n-PlVpanol and Iso-butanol content of all brands were ill the acceptable thresilold value.
For anlyl alcohol five brands contain above the dlleshoJd value and only Olle brand were above
the threshold value fOr edlyl acetate. MEljOlity of dIe alcoholic beCl"S cOll/alI1 acceptable level of
volatIle Oavolll compolwds except for their Iso-amyl acetate and Amyl alcohol content. In
additIOll, level of Viclilal diketones, Acetaldehyde, and DMS in some Ethiopian ,1lcoholic beers
is significant. ThIS shows that the maturatJoll tIine dlUing fellJ1ellfatioll plocess might not be
enough 10 leduce dIe level of these compollflds. As a result of this, brands wid I significant
amoUllt of' acetaldehyde might have hangover effect when conslUlled in large amOllfl! By
consldering customer satIsfactIon, blewers have to take actIons and assess the root causes fOr
those Oavour compOlU/ds which are above the threslJold value. MOIeover, knowledge of some
professlollal employees in the beer factones are nol satIsfaclol)', especially aboul selected
Uavour compounds sllch as VDK
Key wonts: Beer; Fla vow; VDK, DMS, Higher alcohols.. Esters, Quality, Thn:sIJOId, Ethiopia
Description
Keywords
Beer, Flavour, VDK, DMS, Higher alcohols, Esters, Quality, Althreshold Ethiopia