Utilization of chicken eggshells as a source of calcium to enhance the nutritional value and quality characteristics of crackers

Abstract In recent years, there has been a growing demand for healthy snacks, leading to new products containing health-promoting components. Eggshells have emerged as a novel calcium source for human consumption, with potential for use in food products. Hence, this research aimed to examine the effects of substituting wheat flour with different levels (4%, 8%, and 12%) of chicken eggshell powder (CEsP) on the nutritional value physiochemical properties of produced crackers and measure in vivo calcium absorption. The findings of the research indicated that the boiling process of CEsP effectively eliminated any microbial growth on the surface. CEsP supplementation led to a significant increase in the ash content of the crackers without altering the fat and protein content, resulting in a notable decrease in the calorie content. Furthermore, the replacement of wheat flour (WF) with CEsP led to an elevation in the mineral content, particularly calcium, which increased from 25.01 to 2446.1 mg/100 g with a higher replacement ratio of 12%. Moreover, the physical properties of the crackers, including texture and puffiness, exhibited no significant changes when a replacement ratio of up to 8% was used. Additionally, the in vivo evaluation of calcium absorption revealed that the highest absorption rate (44.07%) was achieved at the 8% replacement level. Based on these findings, the addition of CEsP to crackers improved their nutritional quality and physicochemical properties up to an 8% replacement level. Thus, the study proposes using CEsP as a dietary calcium supplement to develop novel calcium-enriched food products.