magistrsko delo
Natalija Borinc (Author), Andreja Goršek (Mentor), Darja Pečar (Co-mentor)

Abstract

Sirotka – mlečna skrivnost, je še vedno premalo cenjen in izkoriščen mlečni produkt. Njene odpadne količine se iz leta v leto povečujejo, zato je smiselno iskati načine za njeno dodatno uporabo. V našem delu smo sirotko uporabili kot medij za rast kefirnih zrn in zasledovali njihovo prirast ter količino nastalega CO2 med fermentacijo. Vse eksperimente smo izvajali v šaržnem reaktorju RC1. Eksperimente smo razdelili na dva dela. V prvem delu smo pri isti vrtilni frekvenci mešala določali prirast mase zrn v odvisnosti od treh različnih temperatur za pet različnih časovnih intervalov. Iz dobljenih podatkov smo s pomočjo matematičnega modela določili pomembne kinetične parametre ter določili matematično zvezo odvisnosti prirasti kefirnih zrn v sirotki od temperature. V drugem delu smo s posebnim merilnikom zasledovali koncentracijo CO2 v mediju pri treh različnih temperaturah in treh različnih vrtilnih frekvencah mešala. Podobno kot pri prirasti, smo izbrali najprimernejši kinetični model za opis sproščanja CO2 ter proučevali vpliv dveh ključnih bioprocesnih parametrov (temperature ter vrtilne frekvence mešala) na potencialno maksimalno koncentracijo CO2, maksimalno proizvodnost CO2 ter čas trajanja lag faze. Dobljeni podatki bi nam lahko pomagali v primeru nadzorovanega poteka fermentacije sirotke s kefirnimi zrni in uravnavanje količine CO2 na željen nivo.

Keywords

kefir;sirotka;fermentacija;proizvodnost CO2;rastna krivulja;Gompertzov model;magistrske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher: [N. Borinc]
UDC: 637.146.21:664.135(043.2)
COBISS: 21029398 Link will open in a new window
Views: 981
Downloads: 116
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Other data

Secondary language: English
Secondary title: Aerobic metabolism of sugars in whey
Secondary abstract: Whey – a dairy secret – is still undervalued and not enough utilized milk product. Its waste quantities are increasing from year to year, thus it makes sense to look for ways of its further use. In our work, we used whey as a medium for the kefir grains growths, we followed their mass increase and the amount of CO2 generated during the fermentation. All experiments were carried out in the RC1 batch reactor. Experiments were divided into two parts. In the first part, at the same rotational frequency of the stirrer, the kefir grain mass increase was determined regarding to three different temperatures for five different time intervals. From the obtained data, important kinetic parameters were determined by means of the mathematical model. Mathematical relation between kefir grains increase in whey and temperature was also determined. In the second part, we measured the concentration of CO2 in the medium at three different temperatures and three different rotational frequencies of the stirrer. Similar to the grain increase, we selected the most appropriate kinetic model describing the CO2 release, and studied the impact of two key bioprocess parameters (temperature and rotational frequency of the stirrer) on the potential maximum CO2 concentration, the maximum CO2 production and the duration of the lag phase. The obtained data could be usefull in the cases of a controlled course of whey fermentation with kefir grains and the adjustment of the amount of CO2 to the desired level.
Secondary keywords: kefir;whey;kefir grains;fermentation;produced CO2 content;Gompertz model;
URN: URN:SI:UM:
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages: XI, 67 str.
ID: 10862799