Physicochemical properties of gelatin produced from Nile tilapia skin using chemical and fermentation pretreatments

In this study, we aimed to verify the effectiveness of fermentation as a pretreatment in Nile tilapia (Oreochromis niloticus) skin gelatin production and assess its effects on extracted gelatin. Chemical-gelatin (CG) fermentation-gelatin (FG) were using hot water from after immersion chemical reagents (sodium hydroxide butanol) with Bacillus velezensis FEL-BM21, respectively. FG presented higher recovery (27.40%), yield (49.99%), imino acid (proline hydroxyproline) content (177.17 ± 0.35 residues/1000 residues) than CG, but had lower molecular weight. Fourier transform infrared circular dichroism spectroscopy confirmed that collagen was denatured, scanning electron microscopy revealed more continuous filamentous structure CG. Furthermore, except for transmittance (66.19% at 450 nm 86.36% 620 nm), exhibited gel strength (492.81 g), gelling point (28.93 °C), melting (18.33 °C) These findings suggest can be used treat raw materials without negatively affecting Moreover, has potential industrial applications an alternative treatment.