Effect of molecular weight distributions on the gelation rate and other physicochemical properties of bovine bone gelatin (Type B)

The physicochemical properties of bovine bone gelatins (Type B) including amino acid and subunit compositions, gelation rate, Bloom values, viscosity, dynamic storage modulus (G'), gelling and melting temperature were investigated comparatively on the basis of molecular weight distributions (MWD). The MWD of gelatin was divided into three segments: >1000 kDa (H), 130 kDa–1000 kDa (M), and <130 kDa (L) for quantitative description and analysis. Results showed similar amino acid compositions for gelatins across different MWD. Gelatins with similar Bloom values exhibited different MWD, whose gelation rate increased with increasing segment H content and decreasing segment M and L content. Viscosity of gelatin was positively correlated with segment H content, and their gelling and melting temperature exhibited little difference. The present study suggests that increasing segment H content or decreasing segment M and L content in gelatin samples can increase the gelation rate and viscosity, making it suitable for 3D food printing.