The limiting partition coefficient is the partition coefficient of a solute at the ice-liquid interface observed at an infinitesimal advance rate of the ice front or infinite mass transfer rate at the interface in progressive freeze-concentration. A method to determine the limiting partition coefficient was proposed based on the concentration polarization model. Electrolytes were concentrated at various operating conditions in advance rate of the ice front (u) and stirring rate (N) in progressive freeze-concentration. The limiting partition coefficients (K 0 ) of NaCl and KCl were obtained from the effective partition coefficients (K) observed under various operating conditions. From K experimentally determined, ln(1/K؊1) was calculated and plotted against u/N 0.2 . This plot showed a linear line, from which K 0 was obtained by extrapolation to u/N 0.2 AE AE AE AE0. The limiting partition coefficient was dependent both on the solute concentration and the chemical species of solute.Keywords: progressive freeze-concentration, effective partition coefficient, limiting partition coefficient, ice crystal growth rate Freeze concentration has been applied to the concentration of fruit juices, the concentration of dairy products, preconcentration of coffee extract before freeze-drying, preconcentration of solutes for analytical purposes, desalination, and waste water treatment (Muller, 1967;Deshpande et al., 1982;Ramteke et al., 1993;Muller & Sekoulov, 1992). For the industrial application of freeze concentration, the suspension crystallization method (Huige & Thijssen, 1972) has been extensively investigated because of its adaptability for scale-up. In this method, it is very important to grow ice crystals large enough to be easily separated from the mother solution (Omran & King, 1974;Shirai et al., 1987). In this method, however, the entire system is complex, involving ice nucleation, ice-crystal growth, and ice separation processes so that the capital cost of the system is very expensive. Therefore, practical application of this method is still limited.As an alternative approach to the suspension crystallization, progressive freeze-concentration is a concentration method in which only a single ice crystal is formed in the system. The separation of an ice crystal from the concentrated mother solution by this technique is much easier than that by the conventional suspension crystallization method (Bae et al., 1994;Liu et al., 1999). The entire system can be simplified to reduce the cost of freeze concentration substantially.In progressive freeze-concentration, the effective partition coefficient of solute between ice and liquid phase is strongly dependent on the ice growth rate and the mass transfer at the iceliquid interface. To analyze effects of these operating conditions on separation efficiency, a concentration polarization model has been successfully applied (Burton et al., 1953;Miyawaki et al., 1998). Using this model, the limiting partition coefficient of solute at the ice-liquid interface has been found to be...

Stability and microstructure of meat emulsion in Kai-yor (Thai chicken sausage) formulated with 4 different lipids and subjected to 2 levels of heat treatment were evaluated. Types of lipids included chicken fat (control), frozen rice bran oil (RBO), pre-emulsified RBO with soy protein isolate (SPI), and pre-emulsified RBO with a mixture of sodium caseinate and microbial transglutaminase (SC+MTG). The heat treatments were cooking and cooking followed by sterilization (cook-sterilization). Meat emulsions were prepared, steamed cooked, packaged in a retort pouch and sterilized. The results showed that frozen and pre-emulsified RBO with SC+MTG increased the stability of meat emulsion indicated by a reduction in fluid release. Hardness and chewiness of all reformulated Thai chicken sausages were higher than those of the control heated by cooking and cook-sterilization. The sterilization process negatively affected texture of all samples, nevertheless the meat emulsion formulated with pre-emulsified RBO with SC+MTG exhibited the lowest percentage decrease in hardness and chewiness. Scanning electron micrographs indicated that differences in the lipid phase affected the microstructure of meat emulsions. Sterilization altered and disrupted the protein matrix to different extents depending on the type of lipid. Replacing chicken fat with pre-emulsified RBO with SC+MTG resulted in greater formation of a protein matrix which was less severely damaged after sterilization than other lipids. It can be concluded that substitution of chicken fat by both frozen and pre-emulsified RBO (with SPI or SC+MTG) showed the potential for producing a cooked meat emulsion with better quality.

Stability and microstructure of meat emulsion in Kai-yor (Thai chicken sausage) formulated with 4 different lipids and subjected to 2 levels of heat treatment were evaluated. Types of lipids included chicken fat (control), frozen rice bran oil (RBO), pre-emulsified RBO with soy protein isolate (SPI), and pre-emulsified RBO with a mixture of sodium caseinate and microbial transglutaminase (SC+MTG). The heat treatments were cooking and cooking followed by sterilization (cook-sterilization). Meat emulsions were prepared, steamed cooked, packaged in a retort pouch and sterilized. The results showed that frozen and pre-emulsified RBO with SC+MTG increased the stability of meat emulsion indicated by a reduction in fluid release. Hardness and chewiness of all reformulated Thai chicken sausages were higher than those of the control heated by cooking and cook-sterilization. The sterilization process negatively affected texture of all samples, nevertheless the meat emulsion formulated with pre-emulsified RBO with SC+MTG exhibited the lowest percentage decrease in hardness and chewiness. Scanning electron micrographs indicated that differences in the lipid phase affected the microstructure of meat emulsions. Sterilization altered and disrupted the protein matrix to different extents depending on the type of lipid. Replacing chicken fat with pre-emulsified RBO with SC+MTG resulted in greater formation of a protein matrix which was less severely damaged after sterilization than other lipids. It can be concluded that substitution of chicken fat by both frozen and pre-emulsified RBO (with SPI or SC+MTG) showed the potential for producing a cooked meat emulsion with better quality.