Transformation of eggshell waste to egg white protein solution, calcium chloride dihydrate, and eggshell membrane powder

Abstract

The present study investigated the possibility of complete utilization of eggshell waste (ESW) transforming it to adherent egg white protein solution, calcium chloride dihydrate, and eggshell membranes (ESM). Adherent egg white protein solution was obtained by washing ESW three times with distilled water at 25°C, followed by filtration, and analyzed for the protein content and lysozyme activity. ESM and calcium chloride were obtained simultaneously by the exposure of washed eggshells to 5% hydrochloric acid treatment at 25°C for 3 h, followed by separation by filtration. The separated ESM were washed, dried, and milled to powder and analyzed for protein and lipid content. The calcium chloride solution was exposed to the neutralization of excess hydrochloric acid by calcium hydroxide, followed by evaporation to one-tenth of volume. Calcium chloride crystals were precipitated from the concentrated solution with acetone, separated by filtration, dried at 110°C, and analyzed for chemical composition and purity. The obtained results revealed that 100 g of ESW can be transformed to 1.61 ± 0.34 g of adherent white proteins containing 485,821 U of lysozyme activity, 2.84 ± 0.16 g of ESM powder, and 108.74 ± 3.62 g of calcium chloride dihydrate of high purity.