Metal-Organic Framework-Encapsulated Transglutaminase Biocatalyst: Enhancing Operational Stability and Freshness...

Area of Science:

• Materials Science
• Biotechnology
• Food Science

Background:

• Enzymatically cross-linked food packaging films using transglutaminase (TG) offer biodegradability and non-toxicity but face enzyme instability and reusability issues.
• Natural enzymes like TG are fragile, limiting their practical application in scalable eco-friendly packaging fabrication.
• Developing robust and reusable enzyme systems is crucial for advancing sustainable food packaging solutions.

Purpose of the Study:

• To immobilize transglutaminase (TG) within HKUST-1 (a copper-based metal-organic framework) using in situ biomineralization with ultrasound assistance.
• To utilize the immobilized enzyme (TG@HKUST-US) for cross-linking zein protein to prepare advanced biodegradable packaging films.
• To evaluate the enhanced stability, reusability, and performance of the TG@HKUST-US immobilized enzyme system in food packaging applications.

Main Methods:

• Immobilization of transglutaminase (TG) within HKUST-1 using in situ biomineralization and ultrasound.
• Cross-linking of zein protein using the immobilized TG@HKUST-US for film preparation.
• Assessment of enzymatic activity, thermal and pH stability, solvent tolerance, water holding capacity, and fruit/vegetable preservation efficacy.
• Evaluation of film toxicity and copper ion leaching levels.

Main Results:

• TG@HKUST-US exhibited 140% higher enzymatic activity than free TG, with improved thermal and pH stability.
• The immobilized enzyme demonstrated enhanced stability in organic solvents and improved pH tolerance.
• Zein films incorporating TG@HKUST-US showed superior water holding capacity, significantly reducing weight loss in apples (41.5%), pears (34.1%), and lettuce (29.5%).
• Films prepared using the reusable TG@HKUST-US system were non-toxic, with copper ion leaching below safety thresholds.

Conclusions:

• The developed TG@HKUST-US system offers a novel and effective strategy for immobilizing enzymes for food packaging applications.
• This approach enhances enzyme stability, reusability, and catalytic efficiency, paving the way for advanced biodegradable films.
• The study establishes a sustainable platform for producing eco-friendly food packaging with improved preservation capabilities.