3-1 |
|
T. C. LANIER, Dept. of Food Science, North Carolina State Univ., 116-C Schaub Hall, Box 7624, Raleigh, NC 27695-7624 The development of surimi as a world-wide commodity was perhaps the first application of a fractionation process to produce food ingredients from a meat source. Grains, oilseeds, and even milk are commonly fractionated to yield specialized products with distinct functionalities which broaden their range of food applications. The soy protein industry is perhaps the best model for this new approach to fish utilization. Soy protein concentrates are prepared by leaching, while soy isolates require alkaline soluilization and isoelectric reprecipitation. The latter process imparts greater functionality but at the expense of lower yields. Similarly,surimi manufacture is a leaching process, yet a recently patened process allows fish meat isolates to be prepared by alkaline soluilization and isolelectric recoverey. Isolate production is however more efficient than surimi manufacture, imparting greater functionality to the proteins via structural changes rather than merely protein concentration. Soy refining also yields valuable food grade oil,lecithins, and bioactive compounds such as isoflavones which can be important components of functional foods. Likewise, fish meat refining yields oils of high omega-3 fatty acid content, as well as specialty collagens, protamines and other bioactive compounds. The alkaline isolate process permits easy separation of many of these components from the fish meat in a low temperature environment that maximizes their stability and utility as food ingredients. Fish fillets and steaks of certain species are high value commodities; thus only trimmings and waste meats from these species would usually be cost effective for fractionation. The more economic, as well as esthetically pleasing, utilization of isolated fish proteins would therefore be as ingredients for marination or other value-added treatment of fillets, wherein the added proteins might take on or protect the high value of the meat to which they are added
Session 3, Fish protein recovery using pH shifts
|