Edible hydrogel from gelatin and alginate as functional low-calorie noodle

There is an urgent need to develop edible hydrogels that can be served as a main dish with low-calorie content and high satiety value, yet are easy to digest. However, the development of such hydrogels remains challenging. In this study, low-calorie edible hydrogels were prepared from gelatin and sodium alginate (gel/SA hydrogels) through a facile acid soaking-drying method. These gel/SA hydrogels exhibited excellent mechanical properties with texture characteristics similar to that of Liangpi. The sensitivity of gelatin and acidified sodium alginate to pH resulted in a high swelling ratio of the hydrogels, contributing to weight retention in a simulated stomach environment and rapid degradation in a simulated intestinal environment. These properties indicate that these gel/SA hydrogels have a good prospect of being used as low-calorie food with high satiety value and are easy to digest. Konjac glucomannan can also be incorporated into the gel/SA hydrogels to further improve their biological functionality.