Effects of vacuum degree on the water status, physicochemical properties and microstructure of fast frozen dumpling wrappers

摘要

Vacuum mixing is a new method of dough making, and little literature is available regarding its effects on the product quality of frozen food. This research studied the effects of different degrees of vacuum (0.00, -0.02, -0.04, -0.06, -0.08 MPa) on the water state, thermal properties, cooking characteristics and microstructure of fast frozen dumpling wrappers during different storage times (0, 14 and 30 days). Vacuum mixing significantly decreased the spin-spin relaxation times (T-2) and freezing water content, thus indicating that it decreased the mobility of moisture and enhanced the binding of dough components with water molecules. Furthermore, the increases in the cooking loss rate and hardness of fast frozen dumpling wrappers during storage were inhibited by vacuum mixing, especially after storage for 30 days, possibly because vacuum mixing formed a more continuous and compacted dough structure, thereby generating a smaller ice crystal structure. These results should provide a theoretical basis for the application of vacuum mixing to fast frozen dumplings.