DYNAMICS OF FREEZING AND THEIR EFFECTS ON THE WATER‐HOLDING CAPACITY OF A GELATINIZED STARCH GEL

摘要

ABSTRACTStarch gels undergo retrogradation when cooled to freezing temperatures. The extent of starch retrogradation as measured by the water‐holding capacity (WHC) was found to be primarily dependent upon the time of residence in the region in the freezing temperature curve where water to ice transformation occurred, and the freezing process used. Very little change in the WHC occurred while precooling the material to the freezing point, and reducing product temperature below the freezing temperature resulted in a very small change in the WHC from that at the end of the phase change. An inverse relationship was observed between the WHC of the frozen starch gel and the extent of reconstitution, as measured by the WHC and viscosity of the product reconstituted after freezing, pressing and dehydration. A readily reconstituted dried starch gel with a low bulk density was obtained when the WHC of the wet material prior to drying was at a minimu