The influence of extraction period on the characteristics of acid soluble collagen from sea catfish (Arius thalassinus) swim bladder

Abstract

The sea catfish in Indonesia is commonly processed into smoked fish and salted fish. The processing of these two products leaves a by-product, namely a swim bladder of 2%. The study investigated the influence of extraction period on the characteristics of collagen from sea catfish (Arius thalassinus) swim bladder. Collagen was extracted from the swim bladder using 0.5 M citric acid with different extraction periods (8, 12, and 16 h). The extraction period of 12 h produced the highest yield of collagen, namely 40.33%. The results showed that the longer extraction, the more amino acids could be extracted from the swim bladder. Glycine was an amino acid that dominates collagen in the amount of 138544.9 to 175420.0 mg/kg. The electrophoresis pattern of protein fraction indicated that the collagen were of type I because it consists of α1 and α2 chains with a molecular weight of approximately 100 to 150 kDa and β chain of 250 kDa. Fourier Transform Infrared (FTIR) spectra of collagen showed the regions of amide A, B, I, II, and III. However, based on the results of the Differential Scanning Colorimetry (DSC), collagen extracted for 16 h had lower thermal stability than the extraction period of 8 and 12 h. Based on these data, sea catfish swim bladder can be used as an alternative raw material for collagen production because it has a higher thermal stability than mammalian collagen, also can be used in the food, pharmaceutical, and nutraceutical industries.