Ecologic and economic motives for transforming calcium-based food wastes into sustainable value-added products: a review.

Abstract

An overview of various industrial and bio-applications of unavoidable bio-waste materials reported in the literature over the last 25 years is presented in this review. Calcium-based food wastes or "unavoidable bio-wastes" are hybrid bio-composite materials, consisting of a softer organic matrix surrounding a stiff mineralized ceramic phase. A wide range of different bio-wastes that are already in use or are investigated for multipurpose applications are presented. Bio-wastes hold considerable potential to contribute more widely to the circular management strategy through, for example, being processed to make new consumer products for a variety of applications, which include the use as a filler in polymers, biogenic hydroxyapatite, limestone or lime in construction products, nutritional feed supplements, soil-improving material and fertilizer, or precursor for making catalysts and adsorbents for the remediation of environmental contaminants. This review summarizes the results of various reported approaches with regard to the development of cost-effective value-added products from under-utilized food waste residues such as eggshells, seafood shells, and animal bones via a simple, eco-friendly, and economically viable approach. Therefore, the work is an advancement toward the goal of achieving a sustainable product by ensuring a holistic design approach from bio-wastes to various salable products, where calcium-based food wastes can compete with non-renewable resources.