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Title:Inaktivacija encimov v živilih : diplomsko delo visokošolskega strokovnega študijskega programa I. stopnje
Authors:ID Prša, Laura (Author)
ID Primožič, Mateja (Mentor) More about this mentor... New window
ID Leitgeb, Maja (Comentor)
ID Kravanja, Gregor (Comentor)
Files:.pdf VS_Prsa_Laura_2019.pdf (2,18 MB)
MD5: 0BB3F721E4E692DD394595AB2FC79BE4
 
Language:Slovenian
Work type:Bachelor thesis/paper
Typology:2.11 - Undergraduate Thesis
Organization:FKKT - Faculty of Chemistry and Chemical Engineering
Abstract:Moka je živilo, ki ga najdemo v vsakem gospodinjstvu in jo uporabljamo za kuhanje in pečenje. Na kakovost moke med drugim vpliva tudi aktivnost encimov v njej. Encimi so naravno prisotni ali namerno dodani v živilih kot aditivi. Pri moki povzročajo oksidacijske procese. Eden od glavnih problemov, ki vplivajo na uporabo moke, je krajši rok uporabnosti zaradi vsebnosti nekaterih encimov. Med skladiščenjem moke, lipidi zlahka vplivajo na njeno obstojnost zaradi encimske hidrolize, ki jo katalizirajo lipaze. Temu sledi oksidacija, kar povzroči izgubo funkcionalnosti moke, okus in hranilne lastnosti. Čeprav smo v literaturi zasledili številne pozitivne učinke encimov na moko, pa smo se zaradi njihovih negativnih vplivov na kvaliteto moke odločili inaktivirati encime α-amilazo, lipazo, peroksidazo in proteazo, ki so prisotni v moki. Encima, ki najbolj vplivata na kvaliteto moke sta lipaza in peroksidaza. Omenjene encime v moki smo želeli inaktivirati z uporabo superkritičnega ogljikovega dioksida (SC CO2). Raziskali smo vpliv procesnih parametrov (tlak, čas izpostavitve in hitrost dekompresije) na aktivnost prostih encimov in encimov v moki. V diplomski nalogi smo omenjene encime podrobneje opisali in določili njihovo aktivnost v moki pred in po izpostavitvi v SC CO2. Prav tako smo tekom eksperimentalnega dela določili koncentracijo proteinov v moki po Bradfordovi metodi. Aktivnost encimov smo določali v beli pšenični moki. Rezultati kažejo, da je po izpostavitvi v SC CO2 preostala aktivnost α-amilaze najnižja. Za primerjavo smo določili tudi aktivnosti encimov v različnih vrstah moke. Ugotovili smo, da največ encimov vsebuje ržena moka in da je bila določena najvišja aktivnost za encim lipazo ne glede na vrsto moke.
Keywords:moka, encimi, α-amilaza, lipaza, peroksidaza, proteaza, superkritični ogljikov dioksid
Place of publishing:Maribor
Place of performance:Maribor
Publisher:[L. Prša]
Year of publishing:2019
Number of pages:IX, 42 str.
PID:20.500.12556/DKUM-73925 New window
UDC:543.645.4(043.2)
COBISS.SI-ID:22605334 New window
NUK URN:URN:SI:UM:DK:DVRNA0TX
Publication date in DKUM:19.07.2019
Views:2396
Downloads:326
Metadata:XML DC-XML DC-RDF
Categories:KTFMB - FKKT
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Licences

License:CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
Link:http://creativecommons.org/licenses/by-nc-nd/4.0/
Description:The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.
Licensing start date:02.07.2019

Secondary language

Language:English
Title:Inactivation of enzymes in food
Abstract:Flour is a foodstuff that is found in every household and is used for cooking and baking. The quality of flour is, among other things, affected by the enzyme activity in it. Enzymes are naturally present or deliberately added into foodstuff as additives. They cause oxidation processes in flour. One of the main problems affecting the use of flour is a shorter shelf life due to the content of certain enzymes. During the storage of flour, lipids can easily affect its shelf life, due to enzymatic hydrolysis, which is catalyzed by lipases. This is followed by oxidation, which results in loss of flour functionality, tastefulness and nutritional properties. Although a number of positive effects of enzymes on flour has been observed in literature, we decided to inactivate enzymes α-amylase, lipase, peroxidase and protease, due to their negative effects on the quality of flour. Enzymes which affect the quality of flour the most are lipase and peroxidase. We wanted to inactivate the mentioned enzymes with the use of the supercritical carbon dioxide (SC CO2). The influence of process parameters (pressure, exposure time and rate of decompression) on the activity of free enzymes and enzymes in flour was researched. In the diploma thesis, the mentioned enzymes were described in detail and their activity in flour before and after exposure in SC CO2 was determined. During experimental work, we also determined the concentration of proteins in flour according to the Bradford method. The activity of enzymes was determined in white wheat flour. The results show that after exposure in SC CO2 the residual α-amylase activity is the lowest. For comparison, we also measured the activity of enzymes in different types of flours. We found that rye flour contains most enzymes and that the activity of lipase enzyme was the highest regardless of type of flour.
Keywords:flour, enzymes, α-amylase, lipase, peroxidase, protease, supercritical carbon dioxide


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