Abstract
The frying properties of the batter used in making Tempura, i.e., Koromo, prepared from wheat protein and starches from waxy maize, maize, wheat, tapioca, and potato, have been examined. The water evaporation rate, oil absorption, breaking strength and sensory evaluation scores of Koromo varied with the starch origin. Among these properties, the water evaporation rate correlated with the breaking strength (r = 0.96), crispness score (r = 0.92) and hardness score (r = 0.97) when the Koromo having a ratio of water to protein-starch of 160% (w/w) was fried at 170t for 60 s. During frying, the temperature of Koromo rapidly increased to about 105°C, at which temperature it remained for a while, and then increased gradually. Koromo, holding a temperature of about 105°C for a long time, showed a higher water evaporation rate. Koromo with a higher water evaporation rate showed a higher breaking strength and crispness score, and was evaluated to have a more favorable quality. Maize starch gave a good quality of Koromo, whereas waxy maize and tapioca starches gave an inferior quality, and wheat and potato starches showed an intermediate quality. Scanning electron microphotographs revealed the presence of starch granules in Koromo of a good quality after frying but absence in Koromo of an inferior quality.
