Evaluation of Enzymatically Modified Soy Protein Isolate Film Forming Solution and Film at Different Manufacturing...

Area of Science:

• Food Science
• Materials Science
• Biochemistry

Background:

• Soy protein isolate (SPI) is a versatile biopolymer with potential for film formation.
• Modifying protein structure is key to tailoring biopolymer properties for specific applications.
• Enzymatic crosslinking offers a targeted approach to alter protein network structures.

Purpose of the Study:

• To investigate the effects of transglutaminase on the rheological and physicochemical properties of SPI films.
• To determine how manufacturing conditions (enzyme treatment, incubation time, denaturation temperature) influence SPI film characteristics.
• To confirm enzymatic crosslinking and its impact on molecular weight distribution.

Main Methods:

• Rheological behavior analysis
• Physicochemical property testing (tensile strength, elongation, contact angle, water absorption, solubility)
• Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)
• Fourier transform infrared (FTIR) spectroscopy
• X-ray diffraction (XRD) spectroscopy

Main Results:

• Transglutaminase treatment, compared to controls, significantly increased tensile strength, elongation, and initial contact angle of SPI films.
• Enzymatic crosslinking was confirmed by viscosity measurements and SDS-PAGE.
• Changes in molecular structure and physicochemical properties were observed at the molecular level.
• The presence of bulk stabilizers in the commercial enzyme also contributed to film property enhancements.

Conclusions:

• Enzymatic treatment with transglutaminase effectively modifies the protein network structure of SPI films.
• The altered network structure influences the behavior and suitability of these biopolymer films for applications like bioplastics.
• Optimized enzymatic treatment provides a feasible strategy for controlling the physical properties of protein-based biopolymeric films.