Quantitative examination of process parameters during kefir grain biomass production

Andreja Goršek (Avtor), Marko Tramšek (Avtor)

Povzetek

This article examines the propagation of kefir grains in fresh HTP whole fat cows' milk, with some additions (glucose and bakers yeast). The objective of our work was an experimental determination of the various process parameters relative influence on the propagation and daily kefir grain increase mass, using the Taguchi method for experimental design. The effects of medium temperature, glucose mass concentration, bakers yeast mass concentration and the rotational frequency of the stirrer at four levels were studied. Orthogonal array layout of L16 was selected for the proposed experimental design. All experiments were performed in an automated laboratory reaction calorimeter RC1 (Mettler-Toledo) with the same milk (3.5 % fat). The gravimetric method was used to determine daily kefir grain mass increases. Relative contributions of the proposed influencing process parameters on the daily kefir grains increase mass were estimated by analysis of the variance (ANOVA). The highest increase (51.5 %) was found at the rotational frequency of the stirrer 90 (1/min), at glucose mass concentration 20 g/L, and at mediumtemperature 24 °C. Within the observed range of yeast mass concentrationthis process parameter was found to be insignificant compared to others. The rotational frequency of the stirrer has the highest relative influence on the daily kefir grains increase mass (37.3 %) while glucose mass concentration and medium temperature have lower ones, 18.8 % and 9.9 %, respectively. The remaining fraction represents error influence. The main reason for its relatively high value (34.0 %) is that kefir grains are bulky and awkward to handle. This fact confirms the importance of optimal kefir grains production management.

Ključne besede

kemijska procesna tehnika;mlečni izdelki;kefir;rast kefirjevih zrn;procesni parametri;metoda Taguchi;RC1;chemical processing;milk products;kefir grain growth;process parameters;design of experiments;Taguchi method;

Podatki

Jezik:	Angleški jezik
Leto izida:	2007
Tipologija:	1.03 - Kratki znanstveni prispevek
Organizacija:	UM FKKT - Fakulteta za kemijo in kemijsko tehnologijo
UDK:	66.01:637.1
COBISS:	11728150
ISSN:	1542-6580
Št. ogledov:	2170
Št. prenosov:	41
Ocena:	0 (0 glasov)
Metapodatki:

Ostali podatki

Sekundarni jezik:	Angleški jezik
Sekundarne ključne besede:	kemijska procesna tehnika;mlečni izdelki;kefir;rast kefirjevih zrn;procesni parametri;procesni parametri;metoda Taguchi;RC1;
URN:	URN:SI:UM:
Strani:	8 str.
Letnik:	ǂVol. ǂ5
Zvezek:	S8
Čas izdaje:	2007
ID:	8717409