A review on the heavy metal adsorption capacity of dietary fibers derived from agro-based wastes: Opportunities and challenges for practical applications in the food industry

Background: Agro-food production processes generate a significant amount of waste, causing a serious environmental burden and a loss of revenue for industry. However, plant food wastes are rich in dietary fibers (DF). These complex carbohydrates offer a variety of human health benefits, including the ability to bind toxic heavy metals like arsenic, cadmium, chromium, lead, and mercury. Therefore, tailoring DF with suitable adsorption capacities can be a sustainable and innovative strategy for agro-based waste valorization.Scope and approach: The aim of this review is to critically evaluate heavy metal adsorption capacity of DF, delving into their possible mechanisms of action, physicochemical characteristics, reusability, and modification technologies to point out their possible applications in a variety of food matrices.Key findings and conclusions: This review confirmed that DF can bind several detrimental components, including heavy metals, and could prevent associated health complications. The binding capacity of DF varies depending on the metal of interest, different physicochemical factors, and process conditions. As adsorption capacity can be significantly enhanced using appropriate modification technologies, the development of suitable strategies for modifying the functional properties of plant DF is a hot topic in the functional food processing industry. However, scientific debates and challenges remain around the practical implications of using DF for heavy metal adsorption in a human model. Therefore, major prospects and challenges are presented together with future research directions for efficient use of DF in the food industry as a sustainable approach to mitigate the impact of food waste.