Changes in the properties of major components of frozen raw noodles during frozen storage

Abstract

Changes in the properties of major components (gluten protein and starch) of frozen raw noodles (FRN) during twelve-week frozen storage were investigated. Frozen storage induced quality deterioration to FRN. Increases in optimal cooking time and cooking loss of FRN were determined. The hardness of noodle texture increased in the first six weeks and then decreased. The gluten from FRN showed decreases in the glutenin fractions with prolonging frozen storage. The compliance (J) of the gluten tended to decrease after the third week, accompanied with increasing zero-shear viscosity (η). The rheological parameters indicate the gluten of FRN became stiffer and less flexible in the latter frozen storage. With prolonging frozen storage, the starch of FRN exhibited higher short-range ordered degrees, revealing the increasing compactness of starch structure which contributed to the longer optimal cooking time required for FRN. Increasing yield stress (σ0) values derived from steady rheological tests indicate the greater force required for the starch gel to initiate flow, which was corresponding to the higher noodle hardness after six weeks. It was concluded that frozen storage induced changes in quality properties of FRN by altering the gluten and starch components.