Effects of frozen storage on the quality characteristics of frozen cooked noodles.

The effects of frozen storage on the quality of frozen cooked noodles were investigated. Texture analysis showed hardness and tensile force reduced during frozen storage. An increasing cooking loss and a decreasing water uptake ratio were determined when testing cooking qualities. As storage time prolonged, differential scanning calorimetry (DSC) detected more freezable water, and an increased relaxation time was recorded by nuclear magnetic resonance (NMR). Magnetic resonance imaging (MRI) revealed water distribution was more heterogeneous. A ruptured microstructure with large pores of frozen cooked noodles was observed by scanning electron microscopy (SEM). The confocal laser scanning microscope (CLSM) photographs demonstrated gluten network lost its integrity and compactness. Size-exclusion high performance liquid chromatography (SE-HPLC) indicated the amount of SDS-soluble proteins increased. The present study showed water characteristics and protein network underwent some changes during frozen storage, which had major effects on the quality of frozen cooked noodles.