Exploring the functional properties and utilisation potential of mollusca shell by-products through an...

Area of Science:

• Materials Science
• Biotechnology
• Environmental Science

Background:

• Molluscan shellfish aquaculture is a significant global industry, generating substantial shell waste.
• Limited research exists on the valorization of shell waste from Australian Akoya oysters (Pinctada fucata) and abalone (Haliotis roei, Haliotis levigata).
• Shell waste disposal poses environmental and financial challenges for the growing aquaculture sector.

Purpose of the Study:

• To characterize the mineral content, elemental profile, and safety of Akoya oyster and abalone shells.
• To identify potential high-value utilization opportunities for these underutilized shell waste streams.
• To provide evidence-based information for the sustainable management of shellfish waste in Australia.

Main Methods:

• Interdisciplinary approach including crude mineral content analysis, elemental profiling, and food safety evaluation.
• Assessment of physical, chemical, and thermal stability using Thermogravimetric Analysis (TGA).
• Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD) for compositional analysis.

Main Results:

• Shells exhibit high thermal stability, indicating potential as functional fillers in engineering.
• Calcium carbonate (CaCO3) is the primary component, with aragonite content up to 77.6%, particularly high in abalone shells.
• Safety evaluations confirm the shells are safe for use as calcium supplements for individuals over 11 years old.

Conclusions:

• The high aragonite content in abalone shells suggests significant potential for biomedical engineering applications due to biocompatibility.
• Shell waste can be safely repurposed as a calcium supplement, offering a viable economic and environmental solution.
• This research supports the Akoya oyster and abalone industries in maximizing waste stream utilization for enhanced sustainability.