Affiliation:
1. College of Food Science and Engineering/Collaborative Innovation Center for Modern Grain Circulation and Safety/Key Laboratory of Grains and Oils Quality Control and Processing Nanjing University of Finance and Economics Nanjing 210023 China
Abstract
SummaryThe effect of 4 °C water cooling treatment after extrusion for different time (0 s, 30 s, 1 min, 3 min, and 5 min) on the structure and cooking characteristics of frozen extruded whole buckwheat noodles were investigated. The cooking time and cooking loss of frozen extruded whole buckwheat noodles significantly decreased after water cooling, and the broken rate was kept constant at 0%, indicating that the quality of frozen noodles was significantly improved. When the time for water cooling was 30 s, the noodles had the lowest cooking loss of 4.07% and the highest hardness and springiness of 3993.19 g and 0.96, respectively. X‐ray diffraction results showed that water cooling treatment increased the crystallinity of starch, and the amylose underwent short‐term ageing. It was also observed from a scanning electron microscope that the gel network structure of the noodles treated with 30 s water cooling was more complete and uniform. Differential scanning calorimetry analysis showed that the water cooling treatment significantly increased the freezable water content. Meanwhile, low‐field nuclear magnetic resonance indicated that the water mobility in the noodles was weakened. The above results showed that 4 °C water cooling treatment for 30 s was beneficial to the formation of starch gel structure and improved the quality of frozen noodles. This study provides a new approach to improve the quality of extruded whole buckwheat noodles.