Chicken eggshell waste and almond flour as potential ingredients in sustainable product development

Chicken eggshells are the 15th major food waste and contain about 94% calcium carbonate and some other components in trace amounts. Almonds (Prunus amygdalus) are nuts that are very rich in essential nutrients which are used extensively in baking purposes for their sweet nutty flavor and also for their general acceptance. The current study was conducted to address food waste problems and dietary calcium deficiency issues by using waste eggshells when grounded and added in the biscuit formulation giving special attention towards its acceptance among the consumers by utilizing almond flour. The results indicated that the developed biscuits with different combinations of wheat flour, almond flour, and eggshell powder showed high levels of calcium and antioxidant contents along with phenolic acids and fatty acids. The treatment T4 was considered best among all treatments as it contained high calcium and antioxidant contents and was also equally acceptable among consumers. The treatment T4 contained 76% wheat flour along with eggshell powder and almond flour replacement at 4% and 20% respectively making it the most desirable one. Based on the current study's findings, it can be concluded that biscuits can be used as an attractive food fortification tool to overcome food waste and dietary calcium problems by utilizing chicken eggshell powder up to 4% level in combination with almond flour for consumer acceptance.