Thesis (PhD)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: This study describes:
· Development of analytical tools to investigate the light struck flavour (LSF) in
beer by Gas chromatography mass spectrometry (GCMS) and by liquid
chromatography mass spectrometry/mass spectrometry (LCMS/MS).
Development of a high performance liquid chromatography (HPLC) method to
analyse carbohydrates in beer.
· The efficiency a pilot scale ultraviolet (UV-C) system at 254 nm to inactivate
spoilage microorganisms spiked in commercial beer. Bacteria test were
Lactobacillus brevis, Acetobacter pasteurianus and Saccharomyces cerevisiae
· A pilot scale UV treatment of commercial and non-commercial lager beers at UV
dosage of 1000 J/L. Following the UV treatment, the correlation between
chemical analyses and sensory tests conducted by consumers’ tasters were
investigated.
· A pilot scale UV treatment of non-commercial beer brewed with reduced hops
iso-α-acids (tetrahydro-iso-α-acids) at UV dosage of 1000 J/L. Sensory changes
and chemical properties were investigated.
· The development and optimisation of an UV light emitting diodes (UV-LED)
bench scale apparatus. Chemical and microbiological tests were conducted to
investigate the effect of UV-LEDs on beer at 250 nm and 275 nm wavelengths. / AFRIKAANSE OPSOMMING: Hierdie studie beskryf:
· Die ontwikkeling van analitiese toerusting om die invloed van lig op die
smaakontwikkeling in bier te bestudeer m.b.v gaschromatografie massa
spektrometrie (GCMS) en vloeistofchromatografie massa spektrometrie/massa
spektrometrie, asook die ontwikkeling van ‘n hoë druk vloeistofchromatografiese
metode vir die analise van koolhidrate in bier.
· Die doeltreffendheid van ‘n toetsskaal ultraviolet (UV-C) sisteem om die nadelige
mikroorganismes waarmee die bier geïnnokuleer was, by 254 nm te inaktiveer..
Toetse is uitgevoer met die volgende bakterieë, Lactobacillus brevis, Acetobacter
pasteuriants en Saccharomyces cerevisiae.
· ‘n Toetsskaal UV behandeling van kommersiële en nie-kommersiële lager biere
by ‘n UV dosering van 1000 J/L. Na UV behandeling is die verwantskap tussen
chemiese analises en ‘n reeks sensoriese toetse deur vebruikers proeërs
ondersoek..
· ‘n Toetsskaal UV behandeling van ‘n nie-kommersiële bier gebrou met verlaagde
hops-iso-α-sure (tetrahidro-iso-α -sure) by UV dosering van 1000 J/L. Sensoriese
veranderinge asook chemiese eienskappe is ondersoek.
· Die ontwikkeling en optimalisering van ‘n UV-lig emissie diodes bankskaal
apparaat. Chemiese en mikrobiologiese toetse is uitgevoer om die effek van UV
lig op bier by 250 nm en 275 nm te ondersoek.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/20365 |
| Date | 03 1900 |
| Creators | Mfa-Mezui, Antoine Aime |
| Contributors | Swart, Pieter, Rautenbach, Marina, Stellenbosch University. Faculty of Science. Dept. of Biochemistry. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | xix, 353 p. : ill. |
| Rights | Stellenbosch University |
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