Changes in the Characteristics of Starch Rich Foods during Quick Freezing (Part 1)

Abstract

Effects of quick freezing of starch rich foods on their paste characteristics were investigated. Flour pastes and roux were frozen at -50-50°C. After being stored at -20°C, they were thawed and the starch gelatinization ratios were determined by the enzymatic digestion method with glyco-amylase. The breaking strength and the firmness of gel were measured by the curd tension meter. The syneresis of gel was also determined.
The following results were obtained.
No significant difference was observed between the starch gelatinization ratios of pastes which were frozen at various temperatures and of unfrozen one. The values of breaking strength, firmness, and the syneresis ratio increased by freezing. The higher the freezing temperature was, the greater these increases were.
The difference between the paste which was frozen at the lowest temperature and then thawed and that which was not frozen was definitely recognized by the sensory test.