Modeling the kinetics of the pectin methylesterase catalyzed de-esterfication of pectin in frozen systems |
| |
Authors: | Terefe Netsanet Shiferaw Nhan Minh Tri Vallejo David Van Loey Ann Hendrickx Marc |
| |
Affiliation: | Department of Food and Microbial Technology, Laboratory of Food Technology, Katholieke Universiteit Leuven, Kasteelpark Arenberg 22, B-3001 Leuven, Belgium. |
| |
Abstract: | The applicability of the William, Landel, and Ferry (WLF) equation with a modification to take into account the effect of melt-dilution and an empirical log-logistic equation were evaluated to model the kinetics of diffusion-controlled reactions in frozen systems. Kinetic data for the pectin methylesterase catalyzed hydrolysis of pectin in four model systems with different glass transition temperatures: sucrose, maltodextrin (DE = 16.5-19.5), carboxymethylcellulose (CMC) and fructose in a temperature range of -24 to 0 degrees C were used. The modified WLF equation was evaluated with a concentration-dependent glass transition temperature (T(g)) as well as the glass transition temperature of the maximally freeze-concentrated matrix (T(g)') as reference temperatures. The equation with temperature-dependent T(g) described the reaction kinetics reasonably well in all the model systems studied. However the kinetics was better described by a linear relationship between log(V(0)/V(0ref)) and (T - T(ref)) in all cases except CMC. The log-logistic equation also described the kinetics reasonably well. The effect of melt-dilution on reactant concentration was found to be minimal in all cases. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|