Nanostructural characterization of catfish skin gelatin using atomic force microscopy

Area of Science:

• Biomaterials Science
• Materials Science
• Nanotechnology

Background:

• Gelatin is a widely used biopolymer derived from collagen.
• Understanding the nanostructure of gelatin is crucial for optimizing its applications.
• Fish gelatin, particularly from catfish skin, offers a potential alternative to mammalian gelatin.

Purpose of the Study:

• To characterize the nanostructure of gelatin extracted from catfish (Ictalurus punctatus) skin.
• To investigate the morphology of gelatin aggregates at the nanoscale.
• To propose a model for the formation of observed nanostructures.

Main Methods:

• Extraction of gelatin from catfish skin following alkaline processing and optimized acid concentration.
• Optimization of atomic force microscopy (AFM) imaging parameters for high-resolution analysis.
• Utilized AFM in height mode (2D and 3D) and error signal mode to visualize gelatin nanostructures.

Main Results:

• First detailed nanoscale description of fish gelatin using AFM.
• Observed distinct nanostructures including annular pores (average diameter 118 nm) and spherical aggregates (average diameter 267 nm).
• Comparison of fish gelatin nanostructure with that of mammalian gelatins.

Conclusions:

• The study provides novel insights into the nanoscale architecture of catfish skin gelatin.
• Proposed a formation mechanism for annular pores and spherical aggregates based on solution penetration during hydrolysis.
• The findings contribute to a deeper understanding of fish-derived gelatin properties and potential applications.