Influence of Physicochemical Properties of Starch on Crispness of Tempura Fried Batter.

The influence of the physicochemical properties of heat-moisture-treated and untreated starches from various plant sources on the quality of tempura fried batter was examined. Batter of each starch plus wheat protein (92:8, w/w) was fried. Quality of the resulting fried batter was determined from crispness score, water evaporation, and breaking strength. The crispness score correlated with water evaporation (r = 0.95) and breaking strength (r = 0.97), indicating that water evaporation was a reliable index for evaluation of crispness of fried batter. Determination of water evaporation was easy and simple. The crispness (favorable eating texture) of tempura coating depended largely on starch origin. Among the pasting properties of starch, temperature at maximum viscosity (r = 0.77) and breakdown/maximum viscosity (% breakdown, r = -0.82) correlated with water evaporation, suggesting that starch resistant to gelatinization and granule disintegration produced crispy fried batter. This observation was supported by SEM. Water evaporation (r = -0.82) and % breakdown (r = 0.95) correlated with degree of amylose gelatinization, indicating that amylose was one of the determinants that controls crispness of fried batter by restraining disintegration of the starch granule structure.