Direct Extraction of Chitosan from Marine Shell Waste

Presenter Information

• Name: Melody Kimi
• Institution: University Malaysia Sarawak

Introduction

• Presentation on extracting chitosan from marine shell waste using a new extraction solution.
• Project Title: Direct Extraction of Chitosan from Marine Shell Waste by Natural Deep Eutectic Solvent.

Background Information

• Approximately 45% of waste in Malaysia is food waste (National Solid Waste Management Department).
• Sustainable Development Goal 12 emphasizes reducing pollution through sustainable consumption and production.
• Marine shells are often discarded and contain chitin, which is a valuable compound.

Chitin and Chitosan

• Chitin:

  • Amino polysaccharide polymer.
  • Comprises about 25% of the dry weight of marine shells.
  • Limited uses due to poor reactivity.

• Chitosan:

  • Formed through deacetylation of chitin.
  • Biodegradable biopolymer with active functional groups.
  • Versatile applications: biofilm encapsulation, binders, substrate delivery.

Conventional Extraction Method

• Commercial chitosan extraction involves three main steps:
  1. Demineralization
  2. Deproteinization
  3. Deacetylation
• Harsh chemicals and high temperatures are typically used.

Alternative Extraction Method

• Natural Deep Eutectic Solvent (NADES):
  • Comprised of at least two natural metabolite components (hydrogen bond acceptor and donor).
  • Current NADES can extract chitin, but not effective for direct chitosan extraction.

Challenges with Current NADES

• Still requires strong bases for the deacetylation process.
• Enhancements needed to eliminate harsh chemicals in the extraction process.

New NADES Solution

• Acetogenin Solution:
  • Capable of extracting chitosan; derived from Graviola leaves (soursop).
  • Deacetylation reaction of chitin to chitosan facilitated by hydroxyl groups from acetogenin.
• New NADES Formation:
  • Acetogenin (hydrogen bond donor) + Choline Chloride (hydrogen bond acceptor).
  • Choline chloride is biodegradable, affordable, and non-toxic.
• This new NADES enables the extraction of pure chitosan in just 2 hours, at room temperature, eliminating harsh chemicals.

Advantages of New Extraction Method

• Extracted chitosan has:
  • Lower moisture content
  • Higher degree of deacetylation
  • Higher molecular weight
• Enhanced reactivity and strength of chitosan polymer compared to commercial products.

Conclusion

• Sustainable single-step extraction process using newly synthesized NADES.
• Safe for use in food, medical, and agricultural industries.
• Represents a natural solution for chitosan production from marine shell waste.

Closing

• Thankful for the audience's attention.