Snakehead fish skin is a rich source of collagen, an important
protein that can be processed into gelatin. In this study, collagen was
extracted from snakehead fish skin using sodium hydroxide (NaOH) and bilimbi
extract. The study aimed to determine the effects of varying the mass of fish
skin and the NaOH soaking duration on gelatin properties. Parameters analyzed
included moisture, ash, protein, and fat contents, gel strength, viscosity,
FTIR spectral characteristics, and overall yield, utilizing a maceration
extraction method at 40°C.
The experiment was performed using various fish skin mass
(50, 100, 150, 200, and 150 g) and different NaOH soaking durations (1, 2, and
3 hours). All skins were also soaked in bilimbi extract for 3 days. The results
showed that 250 g and 3 hours of NaOH soaking obtained gelatin with the yield
of 9.4%, moisture of 2.91%, ash of 1.18%, pH of 6.3, and viscosity of 6.09 cps.
The optimal condition of protein (73.01%) was achieved from 250 g and NaOH
soaking for an hour. The lowest fat content (0.87%) was observed with a 50 g
sample soaked with NaOH for 3 hours, whereas the highest gel strength (302.42
g/cm²) was achieved using a 250 g sample with a 1-hour soaking period with
NaOH.The FTIR spectrum presents a triple helix structure on amide-III band,
indicating collagen as the main component in gelatin formation.
DOI: http://dx.doi.org/10.51505/ijaemr.2026.11302
