Noodle samples were made from wheat flour (9% protein) with 3% (w/w) salt. After cooking, the noodles were placed as soon as possible in two types of home freezer and frozen (1) rapidly and (2) slowly, before being stored for up to 2 weeks. Changes in the rheological properties and degree of gelatinization of the noodle samples with frozen storage time were then studied.
When the stored frozen noodles were thawed at 40°C, the hardness (firmness) of the noodles had increased, while their cohesiveness, tensile strength and maximum elongation had decreased. Young's modulus increased for 3 days after freezing and then decreased. The degree of gelatinization also decreased for the first 3 days of frozen storage, but no further change was observed after that.
When the stored frozen noodles were thawed in boiling water, the time of frozen storage had a little effect on the hardness, tensile strength and degree of gelatinization.
Rapid freezing tended to have less effect on the rheological properties of the noodles than did slow freezing.
The observed changes in rheological properties with storage time might have mainly been influenced by the retrogradation of starch in the noodles.