Food Preservation System with Sericin and Fibroin
Introduction
In the quest for sustainable and effective food preservation methods, silk proteins such as sericin and fibroin have emerged as promising candidates. These biopolymers offer unique properties that can be harnessed to extend the shelf life of perishable foods. This blog serves as a primer for scientists and researchers interested in developing a food preservation system using these silk proteins.
Understanding Post-Harvest Food Preservation
Post-harvest food preservation involves techniques to extend the shelf life of fruits and vegetables after harvest. This is crucial for reducing food waste, maintaining nutritional value, and ensuring food security. Traditional methods include refrigeration, chemical treatments, and modified atmosphere packaging, each with its own limitations.
Why Use Silk Proteins?
Silk proteins, particularly sericin and fibroin, are natural, biodegradable, and non-toxic, making them environmentally friendly alternatives to synthetic preservatives. They form protective coatings that reduce moisture loss and microbial contamination, thereby extending the shelf life of produce.
Developing a Sericin-Based Preservation System
Formulation Process
- Extraction and Purification: Sericin is extracted from silk cocoons through a degumming process, where it is separated from fibroin. The purified sericin is then dissolved in water to create a solution suitable for coating applications.
- Film Formation: Sericin can be combined with other biopolymers like chitosan or alginate to enhance its film-forming properties. This mixture can be applied to fruits and vegetables as an edible coating, creating a barrier against oxygen and moisture.
- Additives: To improve the antimicrobial and antioxidative properties of sericin films, natural additives such as essential oils or plant extracts can be incorporated. These additives can help inhibit microbial growth and prevent oxidative damage.
Application Examples
- Tomatoes: A sericin-based coating combined with chitosan and aloe vera extended the shelf life of tomatoes to 40 days by reducing weight loss and maintaining firmness.
- Mangoes: A study on ‘Nam Dok Mai Si-Thong’ mangoes demonstrated that a 2% sericin coating significantly reduced browning and maintained visual appearance during storage at 10°C for 4 days[1].
Developing a Fibroin-Based Preservation System
Formulation Process
- Extraction and Processing: Fibroin is extracted from silk cocoons and processed into a suspension. This suspension can be tailored to form thin films through a dip-coating process.
- Coating Application: Fibroin coatings can be applied to fruits like strawberries and bananas. The coating process involves multiple dip-coating steps followed by water annealing to enhance the beta-sheet content, which reduces oxygen diffusion and slows respiration rates.
- Enhancements: The incorporation of nanoparticles or crosslinkers can improve the mechanical strength and barrier properties of fibroin films, making them more effective in preserving food.
Application Examples
- Strawberries and Bananas: Fibroin coatings have been shown to extend the freshness of these fruits by up to one week, reducing respiration and water loss.
Table of Silk Protein Applications in Food Preservation
| Silk Protein | Application | Shelf Life Extension | Study Details |
|---|---|---|---|
| Sericin | Tomatoes | Up to 40 days | Coating with chitosan, aloe vera, glycerol |
| Sericin | Mangoes | Maintained appearance for 4 days | 2% sericin coating reduced browning[1] |
| Fibroin | Strawberries, Bananas | Up to 1 week | Reduction in respiration and water loss |
Conclusion
Silk proteins like sericin and fibroin provide innovative and sustainable solutions for food preservation. By leveraging their natural properties and combining them with other biopolymers and additives, researchers can develop effective preservation systems that align with environmental and health standards. As a supplier of high-quality sericin, Serione is committed to supporting the development of these systems. Contact us to explore how our products can enhance your food preservation strategies.
Citations:
[1] https://www.jstage.jst.go.jp/article/hortj/89/5/89_UTD-154/_html/-char/en
[2] https://www.mdpi.com/2311-7524/9/1/64
[3] https://www.scielo.br/j/bjb/a/wkC4J5hmHhZ7XZHv68mYMJJ/
[4] https://www.nature.com/articles/srep25263
[5] https://www.jstage.jst.go.jp/article/fstr/20/5/20_1021/_html/-char/ja
[6] https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2024.1419697/full
[7] https://www.mdpi.com/2073-4360/13/19/3430
