Preparation, Amino Acid Composition, Peptide Fractionation, Thermal and pH Activity Stability of Featherback (Chitala Ornata) Skin Gelatin Hydrolysate with Zinc-Binding Capacity

• Published in: Chemical engineering transactions 2023-12, Vol.106
• Main Authors: Tam D. L. Vo, Thinh N. Tran, Bao C. Vo, Minh C. Tran, Quynh V. N. Nguyen, Bao N. Nguyen, Truc M. X. Le, Nhi H. Y. Bui, Hien T.N. Nguyen
• Format: Article
• Language: English
• ISSN: 2283-9216
• DOI: 10.3303/CET23106146

This research serves as an initial exploration into a novel zinc carrier derived from gelatin obtained from the skin of featherback fish (Chitala ornata), which is a natural source. The skin was found to contain approximately 63.23 ± 0.51 % moisture, 71.18 ± 1.82 % crude protein, 9.13 ± 3.40 % crude lipid, and 19.69 ± 1.61 % ash (on a dry weight basis). To extract the gelatin, warm water was used, followed by hydrolysis using Alcalase. The gelatin-to-water ratio was 1:4 (w/v), with a pH of 8, temperature of 50 °C, enzyme-to-substrate (E:S) ratio of 40 U/g protein, and a hydrolysis time of 4 h. The resulting hydrolysate exhibited a degree of hydrolysis (DH) of 18.46 ± 1.35 % and a zinc-binding capacity (ZnBC) of 39.66 ± 1.56 % (which was 2.00 times lower than that of ethylenediamine tetraacetic acid disodium salt (Na2EDTA)). The hydrolysate's activity remained above 60 % even after exposure to a wide pH range 1-11 and treatment for 180 min at 100 °C. Notably, the hydrolysate contained a significant amount of hydroxyproline (Hyp), measuring 1550 mg/L. Ultrafiltration was utilized to fractionate the hydrolysate, resulting in five peptide fractions (>30 kDa, 10-30 kDa, 3-10 kDa, 1-3 kDa, and