Abstract
The retrogradation of sago starch gel with a high starch concentration was investigated by studying the freeze-thaw stability of the gel. The starch samples tested were sago, corn, potato, tapioca and hydroxy propylated wheat (HPW) starch. Each starch sample was prepared for gelling by heating while stirring or with steam, and the gel was examined for its texture, syneresis and Hunter whiteness. The effect of HPW starch on each starch gel was also examined. A sensory evaluation was conducted on Warabi-mochi, which is a high-starch food, that had been cooked with the 5 kinds of starch and was evaluated by the semantic differential (SD) method. “Sago-mochi” and “potato-mochi ”, which were most preferred among the 5 samples, were chosen for another sensory evaluation to evaluate the influence of the gel preparation method. The firmness of each cooked gel with a high starch concentration was similar among the samples. The gel prepared by heating while did not increase its firmness and syneresis with freeze-thaw cycles as much as the gel prepared by steam did. The addition of 20% HPW starch prevented this increase in firmness and syneresis with freeze-thaw cycles, the inhibitory effect being most marked with the sago starch gel. “Sago-mochi” prepared by heating while stirring was more preferred to that by heating with steam.