| A system was developed by which enzymes can be purified and immobilized simultaneously, decreasing the cost of purification and eliminating the requirement for a downstream inactivation treatment. In addition, the extent of the reactions can be precisely controlled, while the enzyme can be reused indefinitely when properly maintained. Using affinity chromatography, the support can be easily regenerated, further lowering the costs associated with the process.; Limited enzymatic treatment (proteolysis or crosslinking) of whey proteins has been shown, under the appropriate conditions, to enhance existing functional properties. A decrease in the gel point temperature, stronger or more elastic gels, and changes in the infrastructure of the gel network can all be viewed as enhancements depending on the desired application. However, it is necessary to heat-inactivate the enzyme in most cases. Heating can cause undesirable effects on the proteins such as denaturation and production of off-flavors and odors. Using an immobilized enzyme system eliminates the need for inactivation. Also, since most improvements are seen with only a limited degree of modification, the control afforded by immobilized enzymes makes them highly desirable.; Simultaneous purification and immobilization of enzymes to a solid support was demonstrated. The functionality of whey protein isolate was modified using the immobilized catalysts. The degree of modification of the substrates was increased in the presence of calcium and reducing agent. Limited treatment induced significant changes in the gelation properties of the whey. By optimizing enzyme yield and treatment methodology, it should be possible to use immobilized catalysts to produce functionally-distinct protein food ingredients. |
