Quality characteristics, structural changes, and storage stability of semi-dried noodles induced by moderate dehydration

Based on the critical water content (for noodle deterioration) concluded previously, high-temperature–short-time (HTST; 105–135 °C) and medium-temperature–long-time (MTLT; 45–75 °C) dehydrations were introduced in this study to produce semi-dried noodles. The effects of HTST and MTLT on the quality parameters of semi-dried noodles, as well as noodle structure, storage stability, and changes in starch and protein components were thoroughly investigated. Differential scanning calorimeter (DSC) and birefringent analysis presented few starch gelatinization (approximately 30%) in HTST dehydrated noodles. Scanning electron microscopy (SEM) images showed more compact noodle surface, with uniform pores in the cross section, probably due to enhanced protein–starch combination after HTST dehydration. Meanwhile, HTST induced protein polymerizations in semi-dried noodles, mainly by –SH–S–S interchange, and resulted in significantly (P < 0.05) reduced cooking loss. Furthermore, HTST noodles showed higher microbial and color stability. Shelf-life of dehydrated samples at 120 °C was extended to 5 days from 1 day of the control.