Effect of Cross-Linking Agents on Physicochemical, Textural Properties and Microstructure of Canned Soy Protein Isolate-Yellow Alkaline Noodles Prepared by Retort Processing

Soy protein isolate-yellow alkaline noodles (SPI-YAN) prepared by partial substitution of wheat flour with SPI were treated with cross-linking agents namely microbial transglutaminase (SPI-MTG), ribose (SPI-R) and the combination of both (SPI-R-MTG). SPI-YAN were either unprocessed (UP), thermally processed at 121C for 30min (P), or thermally processed and followed by 3 weeks storage at ambience (PS). The thermal, storage treatments and formulation had an impact on the physicochemical properties of SPI-YAN. pH and textural parameters of P-noodles were lower than those of UP-noodles, while PS-noodles showed higher water absorption, thickness, but lower textural parameters. For P and PS-noodles, SPI-R showed the highest retort cooking loss, water absorption, redness and yellowness, but the lowest in pH values, while SPI-MTG exhibited the lowest retort cooking loss, thickness, yellowness, but the highest textural parameters. Scanning electron microscopy images indicated an enhanced network microstructure of SPI-MTG and SPI-R-MTG following thermal processing and/or storage. Practical Application Thermal processing of canned noodles causes damage to overall structure and affects sensory appeals. The present work describes the effects of cross-linking agents (microbial transglutaminase [MTG] and ribose) on the physicochemical and physical properties of canned soy protein isolate-yellow alkaline noodles prepared by retort processing, and their impacts during storage. The main finding is that the use of MTG maybe helpful in improving retorted noodles' texture during thermal processing. This information can further stimulate the application of MTG in preserving the texture and edibility of canned noodles.