Calcined waste shells as a promising, eco-friendly adsorbent, antimicrobial, food preservative, and food packaging material: A mini review

Conventionally, waste shells from aquaculture are dumped as a low-value byproduct, which deteriorates ecosystems and threatens public health. Therefore, the reuse of waste shells is a pivotal issue. Calcination (>= 700 degrees C) can thermally convert calcium carbonate (CaCO3; the main component in waste shells) into active calcium oxide (CaO). This calcined shell powder has adsorption properties, antimicrobial properties, and biocompatibility, which can be used as a functional biofiller in food packaging. Calcined shell powder is also ecofriendly and nontoxic at the concentrations required for food processing and packaging, and has been approved as a food additive in Japan. Thus, this review comprehensively discusses the calcination process, compositions, adsorption and antimicrobial properties (and the underlying mechanisms), and applications of calcined shell powder in food processing and packaging.