Impact of impingement drying on microstructure, porosity and textural properties of instant noodles compared to frying

Abstract

The global instant noodle market has grown steadily, with air-dried noodles emerging as a healthier, lower-fat alternative to fried varieties. However, their denser structure leads to poor rehydration and a firmer texture. This study evaluates impingement drying as a potential alternative, investigating how specific drying conditions (130-170 degrees C; 15-30 m/s) influence the microstructure, rehydration, and textural properties of instant noodles. Xray microcomputed tomography revealed that higher temperatures and air velocities increased porosity and pore interconnectivity, although pore size distributions remained narrower and skewed toward smaller pores compared to fried noodles. These structural changes correlated positively with rehydration capacity and improved texture. Noodles dried at higher impingement intensities exhibited cooking quality attributes closest to those of fried noodles, while further increases in drying severity did not yield additional improvements. Texture profile analysis confirmed that porosity and pore connectivity were key predictors of reduced hardness and chewiness. Overall, the results highlight the crucial role of microstructure in determining the functional performance of instant noodles and support impingement drying as a promising, scalable method for producing high-quality, low-fat noodles with desirable cooking properties.