Effects of Enzymes to Prevent Hardening of High Moistured Cereal Flour Gels

Abstract

High moistured cereal flour gels harden easily on their short time storage. To prevent hardening of the gels, α-amylase, β-amylase, glucoamylase or papain was added to rice and wheat flour gels at several concentrations and stored in a refrigerator for 1 to 3 days. The changes in hardness of their gel strength were measured by use of Autograph (Instron type testing machine). The gel strength of rice and wheat flour gels was markedly decreased with addition of 0.0005 to 0.005% α-amylase and hardening were delayed. But the use of α-amylase was unsuitable for gel formation in the textural aspect. The addition of β-amylase at the concentrations of 0.05 to 0.1% delayed effectively the increase of gel strength in rice flour gel, but not so effective to wheat flour gel. Glucoamylase and papain were little effective to depress the increase of gel strength on storage at a lower temperature. Hardening of the Uirou (a confectionery of rice flour gel) prepared experimentally with addition of 0.05 to 0.1% β-amylase was considerably delayed and its good texture was retained during storage.