Antimicrobial Properties of Thermally Processed Oyster Shell Powder for Use as Calcium Supplement.

Area of Science:

• Materials Science
• Food Science
• Environmental Science

Background:

• Oyster shells are a rich calcium source but often discarded, causing environmental issues.
• Developing functional calcium-based materials from waste is crucial for sustainability.
• Low bioavailability of raw calcium sources necessitates processing for enhanced applications.

Purpose of the Study:

• To evaluate the physicochemical properties and antimicrobial activity of processed oyster shells.
• To compare thermally processed pulverized oyster shells (TPOS) and citric acid-treated TPOS (TPOSc) with reference calcium products.
• To assess the practical application of TPOS and TPOSc in food products.

Main Methods:

• Physicochemical characterization using solubility, particle size analysis, SEM, EDS, and XRD.
• Antimicrobial activity testing against bacteria.
• Incorporation of TPOS and TPOSc into rice cakes to evaluate efficacy and textural impact.

Main Results:

• TPOS and TPOSc demonstrated significant calcium ion release and structural modifications.
• Both TPOS and TPOSc exhibited notable antimicrobial activity.
• Rice cakes incorporated with 0.3 wt% TPOS or TPOSc retained antimicrobial properties without significant textural degradation.

Conclusions:

• Thermally processed oyster shell powders possess valuable antimicrobial properties.
• These materials offer a sustainable solution for microbial control in food applications.
• Optimized concentrations of TPOS and TPOSc can be used in food products with minimal impact on quality.