Sustainable Synthesis of Calcium Propionate from Cockle Shell Biowaste for Food Additive Production

Area of Science:

• Materials Science
• Green Chemistry
• Biotechnology

Background:

• Seafood processing generates significant biowaste, such as cockle shells, presenting disposal challenges.
• Valorizing biowaste aligns with circular economy principles, transforming waste into valuable resources.
• Calcium propionate (E282) is a widely used food preservative, but its production can be optimized for sustainability.

Purpose of the Study:

• To synthesize calcium propionate from cockle shell biowaste.
• To evaluate the efficiency of using varying concentrations of propionic acid for synthesis.
• To demonstrate a sustainable and cost-effective method for producing a food additive from waste.

Main Methods:

• Cockle shells (calcium carbonate source) reacted with propionic acid (80%, 90%, 99%) at ambient temperature.
• Fixed CaCO3: propionic acid molar ratio of 1:2.
• Characterization using FTIR, XRD, TGA, SEM, and XRF.

Main Results:

• Successful synthesis of calcium propionate monohydrate (Ca(CH3CH2COO)2·H2O).
• XRF analysis confirmed >97 wt% CaO with non-toxic impurities meeting food additive standards (E282).
• The highest yield (90.24%) and solubility (98.23%) were achieved using 80% propionic acid.

Conclusions:

• Cockle shell biowaste can be effectively valorized into food-grade calcium propionate.
• The synthesis method is sustainable, cost-efficient, and scalable, suitable for industrial application.
• This approach supports circular economy goals by repurposing seafood waste into valuable food additives.