Grass turtle (Chinemys reevesii) is an aquatic animal species of the Geoemydidae family, which is found in many countries, particularly in Hong Kong, China, Taiwan, Japan, and Korea (Dai et al., 2012). At present, research studies are focused on the practical utilization of various aquatic animal species products and their by-products (Zou et al., 2017). Tortoises and turtles have long been used for foods and medicines in the East and Southeast Asia, while China is the largest consumer country in the world. The soft-shelled turtles (Pelodiscus sinensis) is a commercially important and delicious aquatic species due to their higher nutritional value and medicinal benefits, where they can be used for anticancer, antioxidation, and reduces blood pressure. The global production of soft-shelled turtles is estimated to be 355,000

Soybean protein hydrolysates were prepared using two proteolytic enzymes (Alcalase and Protamex) and the degree of hydrolysis (DH) and their functional and antioxidant properties were evaluated. The highest DH value was 20%, with a yield of 19.77% and protein content of 51.64%. The total amino acid content was more than 41% for all protein hydrolysates. The protein hydrolysates from Protamex at pH 2.0 had excellent solubility, emulsifying activity, and foaming capacity, at 83.83%, 95.03 m2/g, and 93.84%, respectively. The water-holding capacity was 4.52 g/g for Alcalase, and the oil-holding capacity was 4.91 g/g for Protamex. The antioxidant activity (62.07%), as measured by the samples’ reaction with DPPH (2,2-diphenyl-1-picrylhydrazyl) and the reducing power (0.27) were the strongest for Protamex. An ABTS activity rate of 70.21% was recorded for Alcalase. These findings indicated a strong potential for the utilization of soybean protein hydrolysates to improve the functional properties and antioxidant activity of soybeans as well as their nutritional values.