Degree of hydrolysis, functional and antioxidant properties of protein hydrolysates from Grass Turtle (Chinemys reevesii) as influenced by enzymatic hydrolysis conditions

Md Serajul Islam; Wang Hongxin; Habtamu Admassu; Anwar Noman; Chaoyang Ma; Fu An Wei

doi:10.1002/fsn3.1903

Degree of hydrolysis, functional and antioxidant properties of protein hydrolysates from Grass Turtle (Chinemys reevesii) as influenced by enzymatic hydrolysis conditions

Food Sci Nutr. 2021 Jun 24;9(8):4031-4047. doi: 10.1002/fsn3.1903. eCollection 2021 Aug.

Authors

Md Serajul Islam^{1

2

3}, Wang Hongxin^{1

2}, Habtamu Admassu⁴, Anwar Noman¹, Chaoyang Ma², Fu An Wei⁵

Affiliations

¹ State key Laboratory of Food Science and Technology Jiangnan University Wuxi Jiangsu province 214122 China.
² National Engineering Research Center for Functional Food Jiangnan University Wuxi Jiangsu province 214122 China.
³ Department of Food Technology and Nutritional Science Mawlana Bhashani Science and Technology University Tangail Bangladesh.
⁴ Department of Food Process Engineering, Biotechnology and Bioprocessing Center of Excellence Addis Ababa Science and Technology University Addis Ababa Ethiopia.
⁵ Guangxi zhongtaikang Technology Industry Co., Ltd. Nanning Guangxi 530029 P. R. China.

Abstract

Grass turtle muscle was hydrolyzed with papain enzyme to produce protein hydrolysate (PH) and the degree of hydrolysis (DH) was determined. Under optimal conditions, the highest DH was 19.52% and the yield was recorded as 17.26%. Protein content of the hydrolysates was ranged from 73.35% to 76.63%. Total amino acids were more than 96.77% for each PH. The PH obtained at DH 19.52% achieved excellent solubility and emulsifying activity which were 95.56% and 108.76 m²/g, respectively at pH 6. Foam capacity amounted 100% in PH of DH 19.52% at pH 2, and water-holding capacity was 4.38 g/g. The antioxidant activity showed the strongest hydroxyl radical scavenging activity (95.25%), ABTS (84.88%), DPPH (75.89%), iron chelating (63.25%), and cupper chelating (66.90%) at DH 11.96%, whereas reducing power (0.88) at DH 19.52%. Thus, the findings indicated that utilization of grass turtle muscle protein hydrolysate is a potential alternative protein resource to improve the nutritional and functional properties in food ingredients and product formulations.

Keywords: Antioxidants activities; Chinemys reevesii; Enzymatic hydrolysis; Functional properties; Protein hydrolysate; Scanning electron microscopy (SEM).