THE PROPERTIES OF GELATIN FROM THE SKIN OF TERUBUK FISH (TENUALOSA TOLI)

Abstract

Gelatin was successfully extracted from the skin of terubuk (Tenualosa toli) by alkaline and acid pre-treatment method with the yield of 25.12%. The functional group, pH value, and sensory, foaming and emulsifying properties were studied. The FTIR spectra showed that the gelatin has major absorption bands in the amide region. The pH of the gelatin was in acidic range. The sensory evaluation showed that the gelatin has a strong but not offensive odour with the mean sensory of 2.55. The gelatin has low foaming capacity as well as foaming stability with 10% and 6% respectively. The low foaming capacity could be due to the lower percentage of negatively charged amino acids. For emulsifying properties, it showed that the increased of the concentration of gelatin solution the decreased of emulsifying activity index (EAI) as well as the emulsifying stability index (ESI). This might because of at high protein concentration, the diffusion is limited due to the activation energy barrier. Meanwhile, at low protein concentration favours higher EAI because of the ability of the protein to diffuse and adsorb at the oil water interface.