Antistaling of rice starch in a gel model system and Korean rice cake: the role of wheat flour in retrogradation-retardation technology

This study focused on the mechanisms of retrogradation-retardation technology for applications in garaetteok (steamed and extruded cylinder-shaped rice cake) production. Based on the comparison of conventional and retrogradation-retardation methods, the addition of raw wheat flour was selected as a key process. The rheological properties of gelatinized rice starch pastes after treatment with raw or autoclaved wheat flour and Novamyl L were investigated. Among them, raw wheat flour and Novamyl L resulted in significantly lowered the elastic modulus. The textural properties of garaetteok treated with raw or autoclaved wheat flour were examined by texture profile analysis (TPA) during storage for 3 days at 4°C. The hardness of garaetteok made with raw wheat flour was maintained for up to three days. In contrast, autoclaved wheat flour did not affect elastic modulus or hardness. As a result, raw wheat flour effectively retards starch retrogradation through starch hydrolysis induced by amylase in wheat flour.