Characterization of collagen from Java barb (Barbonymus gonionotus) skin and its effect on selected properties of yogurt

Abstract

Wastes of Barbonymus gonionotus (Java barb) skin can be processed as collagen as a food additive. Yogurt is a functionaldrink that has gained attention.  This study aimed to characterize yogurt added with collagen from Java barb skin. The solutions used to extract the collagen were (A) 1:10 (w/v) for 24 h, (B) 1:20 (w/v) for 24 h, (C) 1:10 (w/v) for 36 h, and (D) 1:20 (w/v) for 36 h. The obtained collagen was added to yogurt at concentrations of 1%, 2%, and 3%. The yogurt was then examined for its protein content, pH, and titratable acidity. The highest yield of collagen was obtained from treatment D, with a value of 52.54% ± 0.94%. All the extracted collagens had triple-helix structures. The presence of α1 and α2 was also confirmed by sodium dodecyl-sulfate polyacrylamide gel electrophoresis, and the amino acid patterns were found to be either Gly-Pro-Ala or Gly-Pro-Arg. The addition of collagen to yogurt at a concentration of 3% produced a significant increase in protein content (3.82%). In comparison, pH and titratable acidity did not show any significant changes. However, the titratable acidity at a collagen concentration of 3% showed a small increase of 1.14% ± 0.71% at the end of fermentation. In conclusion,collagen was successfully extracted with relatively high yields, and collagen-added yogurt met industry standards. The addition of collagen at a concentration of 3% increased the protein content of yogurt and only had a slight effect on its selected characteristics.