application of dynamic pH profiles
Marko Tramšek (Author), Andreja Goršek (Author)

Abstract

The profiles of kefir grains growth curves strongly depend on bioprocess conditions and inoculum viability. Therefore, accurate growth curve studies require the use of optimally active kefir grains as inoculum. Accordingly, the main objective of our study was experimental optimization of classic kefir grains activation procedure and afterwards, comparison among growth curves of differently activated kefir grains. For this purpose some experiments were initially performed in computer-controlled RC1 reactor provided data of dynamic pH profiles during batch propagation of differently activated grains. Experimental data were mathematically analyzed and using the special methodology of minimizing the absolute deviation of pH(t) profiles the minimaltime for grains activation was determined. We established that optimal inoculum activity could be ensured only by the kefir grains, which were previously activated at least over eleven successive days. In the second part of research the growth curve of optimally activated kefir grains was constructed using experimental measurements and fitted with Gompertz model. The present results were compared with the results obtained by our previous study, where classically activated grains were used. We established that, inspite of equal daily kefir grain mass increase, considerable difference in growth curves of differently activated kefir grains exist.

Keywords

kemijska procesna tehnika;kefirjeva zrna;modeli rasti;minimlani aktivacijski čas;Gompertzov model;chemical processing;kefir grains;growth curve;minimal activation time;dynamic pH profiles;Gompertz model;

Data

Language: English
Year of publishing:
Typology: 1.01 - Original Scientific Article
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
UDC: 66:519.853
COBISS: 11991062 Link will open in a new window
ISSN: 1318-0207
Views: 1559
Downloads: 88
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Other data

Secondary language: Slovenian
Secondary abstract: Profili krivulj rasti kefirnih zrn so v veliki meri odvisni od bioprocesnih pogojev in aktivnosti inokuluma, zato so za njihove natančne študije potrebna optimalno aktivna zrna. Namen naše raziskave je bil v prvi fazi eksperimentalno optimiranje klasičnega postopka aktivacije kefirnih zrn in nadalje primerjava krivulj rasti različno aktiviranih zrn. V ta namen smo v računalniško vodenem reakcijskem kalorimetru RC1 izvedli serijo eksperimentov, pri katerih smo zasledovali spreminjanje pH vrednosti med šaržnim razmnoževanjem različno aktiviranih kefirnih zrn. Eksperimentalne podatke smo matematično analizirali in hkrati s posebno metodologijo minimiziranja absolutnega odstopanja pH(t) profilov določili minimalni čas aktivacije zrn. Dokazali smo, da optimalno aktivnost inokuluma lahko zagotovimo le z zrni, ki so bila predhodno aktivirana najmanj 11 zaporednih dni. V drugem delu raziskave smo na osnovi eksperimentalnih meritev konstruirali krivuljo rasti optimalno aktiviranih zrn in jo prilegali k Gompertz-ovemu modelu. Dobljene rezultate smo primerjali s podatki iz predhodne raziskave, kjer so bila uporabljena klasično aktivirana zrna. Ugotovili smo, da kljub enakemu dnevnemu prirastu obstajajo znatne razlike v krivuljah rasti različno aktiviranih kefirnih zrn.
Secondary keywords: kemijska procesna tehnika;kefirjeva zrna;modeli rasti;minimalni aktivacijski čas;Gompertzov model;
URN: URN:NBN:SI
Type (COBISS): Scientific work
Pages: str. 693-699
Volume: ǂVol. ǂ54
Issue: ǂno. ǂ4
Chronology: 2007
Keywords (UDC): applied sciences;medicine;technology;uporabne znanosti;medicina;tehnika;chemical technology;chemical and related industries;kemijska tehnologija;kemijske in sorodne industrije;mathematics;natural sciences;naravoslovne vede;matematika;mathematics;matematika;operational research (or): mathematical theories and methods;operacijsko raziskovanje;mathematical programming;
ID: 13203