Extraction and Characterization of Gelatin from the Head Waste of Tiger Tooth Croaker (Otolithes ruber)

Purpose The objective of the present study was to valorize the tiger tooth croaker ( Otolithes ruber ) fish head waste for the extraction of high value protein based component ‘gelatin’. Methods Gel strength, gelling and melting point and setting time, viscosity, turbidity, colour, emulsion activity and stability index and SDS–PAGE technique. Results The gel strength of extracted croaker fish head waste gelatin was 45 g and had lower gelling (11 °C) and melting temperature (20.25 °C) and took more time (366 s) to gel at 11 °C compared to standard porcine gelatin of low bloom category. Colour analysis revealed that the whiteness and redness intensity of fish head waste gelatin were lower than the porcine gelatin. However, there was no significant difference in yellowness value between fish head waste gelatin prepared and porcine gelatin. The emulsion activity index of fish head waste gelatin decreased with increase in protein concentration. The SDS–PAGE analysis showed the presence of α-component and multiple low molecular weight peptides up to 45 kDa. Conclusion Croaker fish head waste could be utilized for extraction of gelatin of low bloom category. Appropriate changes could be incorporated in the process to obtain gelatin with higher gel strength.