Valorization of Eggshell Waste into Calcium and Collagen-Based Nutritional Supplements

Abstract

Aims: Utilizing eggshell waste is a comprehensive solution that tackles the issues of waste accumulation in the environment, pollution, and financial resources allocated to its disposal while producing high-value goods. This study aims to repurpose this waste to produce nutritional supplements used in various industries, including calcium carbonate, calcium citrate, eggshell membrane protein, and hydrolyzed collagen powder. Place and Duration of Study: Department of Meat and Fish Technology Research, Food Technology Institute, Agricultural Research Center, Egypt, between August 2023 and July 2025. Methodology: In this study, eggshells were used to produce calcium carbonate and calcium citrate that can be used as supplements or food fortification. In contrast, eggshell membrane was employed to make a high-protein food supplement (eggshell membrane protein and hydrolyzed collagen powder). Results: The eggshell ash content represents 94.92%, while the eggshell membrane protein content represents 83.36%. Furthermore, the eggshell membrane contains a high content of amino acids proline, glutamic, glycine, and hydroxyproline, which represent 11.18%, 8.43%, 10.97%, and 7.17%, respectively. While, the hydrolyzed collagen powder produced was composed of 91.27% protein, with the predominant amino acids being glycine, proline, hydroxyproline, arginine, and glutamic acid, accounting for 10.87%, 8.59%, 6.25%, 5.7%, and 4.61%, respectively. The findings indicated that the hydrolyzed collagen powder had a total bacterial count of 3.6×102 cfu/g. No Salmonella or E. coli were detected. Eggshell powder was used to improve the calcium content of chicken meatballs. Sensory evaluation of chicken meatballs with different fortification (0, 3, 5 and 7%) indicate that samples contained 0% eggshell powder had higher texture followed by 3 and 5% while samples contained 7% eggshell powder was the lowest. The result showed that meatballs tell 5% fortification was acceptable to panelists splenic. Conclusion: The study's findings support the potential use of the nutritional supplements present in eggshell membrane and eggshells, which are made as hydrolyzed collagen powder and calcium carbonate and citrate. To improve their usefulness, future initiatives should concentrate on increasing production to integrate these supplements into functional foods.