Alkaline Salts to Preserve and Improve the Quality of Fresh Wet Noodles

In order to explore the effects of alkaline salts on the shelf life and quality characteristics of fresh wet noodles, five alkaline salts (sodium carbonate, potassium carbonate, trisodium phosphate, tripotassium phosphate and sodium bicarbonate) at different addition levels were used to make noodles. The optimal addition level of each alkaline salt was determined based on the total plate count, L* value and apparent quality of fresh wet noodles. The effects of the alkaline salts on the quality of fresh wet noodles were comprehensively analyzed by measuring the pH, cooking quality and microstructure of raw noodles and the texture characteristics and sensory quality of cooked noodles as well as the rheological properties of dough. The results showed that compared with the control group, the addition of alkaline salts effectively inhibited microbial growth in fresh wet noodles. Adding 2.0% of sodium carbonate prolonged the shelf life of fresh wet noodles by 2.5 times. The alkaline salts resulted in a bright yellowish color and significantly improved the apparent quality of noodles. The optimum addition level of sodium carbonate in fresh wet noodles was 1.0%, and the optimum addition level of the other four alkaline salts was 1.5%. The alkaline salts regulated and stabilized the pH of noodles during storage, significantly enhanced the water absorption and tensile properties of dough, and reduced the weakening degree of dough; the extensibility of dough with added alkaline salts decreased with proofing time. In addition, the addition of alkaline salts increased the cooking loss, reduce the water absorption, and improve the hardness, tensile strength, elasticity, viscosity and palatability of noodles. Scanning electron microscopy (SEM) showed that the addition of alkaline salts enhanced the degree of cross-linking of protein and starch in noodles, thereby resulting in the formation of a more continuous and dense gluten network structure. Among the alkaline salts, sodium carbonate has the most prominent effect on improving the quality of fresh wet noodles.