Development of eggshell powder as an alternative source of Ca and Fe for human health: A compositional and comparative study

• Eggshell powder (ESP) contains more than 90% ash, which is enriched with Ca and contains a small amount of Mg, Fe, and Zn. • ESP comprises 6 to 7% protein, where all essential amino acids are present, particularly in domestic chicken ESP. • All species ESP particle size is 3 to 5 μm, which is suitable for consumers to add to various foods. • 1 g of ESP may fulfill half of the daily demand of Ca of an adult and is equivalent to one multimineral tablet supplement. Eggs are the most common animal food consumed by people, but most of the eggshells are thrown away as waste material. This study aimed to explore the nutrient profile of three different species (domestic chicken, duck, poultry) of eggshell powder (ESP), calculate the percentage contribution to the daily value (DV), and compare with multimineral supplements available in Bangladesh. We estimated the proximate composition, amino acid, and mineral profiles of ESP. Our findings suggest that all kinds of ESPs contain more than 90% ash, which is enriched with Ca (549.36–570.56mg/g) and a small amount of Mg, Zn, Fe. Additionally, ESPs contain 6-7% protein, which comprises all essential amino acids, particularly in domestic chicken ESP. According to SEM study, ESP particle size was tiny (3-5 μm), which is suitable for adding to other foods. Moreover, 1 g of ESP was almost equivalent to 1 multimineral tablet and was able to fulfill more than 50% of the DV of calcium. This compositional and comparative analysis of ESP revealed that ESP might be a good source of Ca and other microminerals, which will help to improve mineral deficiency and reduce osteoporotic conditions. However, it is necessary to create awareness and public perception regarding the use of EPS.