Evaluating criteria for assessing sustainable bread prepared with olive oil mill wastewater: a multi-criteria-based approach

Abstract

In recent years, consumers have shown an increasing preference for foods that promote health, benefit society, and respect the environment. This paradigm shift has increased interest in food innovation and enrichment, including the use of substances derived from processing by-products. Transforming waste into valuable resources represents a critical global challenge and a key driver for advancing the circular economy model. In this context, Olive Oil Mill Wastewater (OOMW) is a by-product of the olive milling process which offers a sustainable solution for managing agri-food residues and enhancing resource efficiency in olive oil production. Rich in polyphenols, this waste holds potential for enhancing health properties of staple foods such as bread. However, determining the optimal formulation for innovative bread requires a detailed identification and evaluation of the criteria that impact the quality, the sustainability in terms of water footprint, and the acceptability of the final product. This study focuses on identifying these critical criteria and employs a multi-criteria decision-making approach, using the Group Best Worst Method (G-BWM) to prioritize them. By engaging a panel of experts, the study highlights how G-BWM can effectively handle complex decision-making processes, ensuring that the most relevant factors are considered and establishing clear priorities for each criterion. Results show that the key factors influencing the evaluation of OOMW-added bread are sustainability, specific volume, cell density in the crumb, and sensory characteristics, particularly aroma. Despite differences in structure, these findings suggest that the acceptability of the product is primarily driven by sensory perception and the environmental benefits of this innovation.