**5. Improving the textural, structural, and cooking properties of air-dried rice noodles using SPI and combined cross-linking technologies**

Despite having improved texture, taste, and flavor, fresh rice noodles deteriorate after preparation and are susceptible to spoilage due to their high moisture levels. Furthermore, fresh noodles are prone to discoloration, which is unappealing [33]. As a result, reducing the moisture content will extend the shelf life of the noodles while also preserving their texture and aroma, potentially increasing their market value [34]. Because of their less porous structure, air-dried noodles have been confirmed to shrink during processing, have poor rehydration characteristics, develop a tough texture, and have long cooking times [35, 36]. This problem could be solved by carrying out a steaming process before drying.

Therefore, RNS-COM was steamed before drying to yield air-dried RNS-COM (**Figure 4**). Findings revealed that RNS-COM was chewier and springier than air-dried RN because of the improved swelling of starch molecules in the noodle framework. Furthermore, the protein cross-links formed by MTG and GDL reinforced covalent networks in the noodles, increasing the chewiness. The springier the noodles, the denser the cross-links between amylose and other network forming molecules in a noodle structure [37, 38]. The improved springiness of the RNS-COM could be attributed to increased polymerization prompted by the additional proteins and cross-linking agents. GDL may have prompted some cold protein gelation and better overall interactions between starch molecules, resulting in stronger and harder RNS-COM with enhanced starch retrogradation on the noodles' surface [39].

### **Figure 4.**

*Air-dried RNS-COM (RNS-COM = rice noodles with 5% SPI, crosslinked with 1% MTG and gelled with 1% GDL)*

Initially, the structurally optimized air-dried RNS-COM suffered a longer cooking time and a reduced yield; however, this was resolved by using pre-drying steaming treatments for 5 or 10 min. The subsequent air-dried RNS-COM had shorter cooking times, lower cooking losses, and higher yields. The microstructures of the steamed and dried combinedly-treated RNS-COM differed noticeably, but the relative crystalline structure of starch was preserved just after the steaming and drying treatments [40].
