Integrating Circular Economy Strategies for Sustainable Citrus Supply Chains

The food supply chain (FSC) and food loss and waste (FLW) are vital concerns globally. Among all categories, agricultural products contribute significantly to FLW, which still can be used to generate value out of it. Citrus products and citrus supply chains (SC) receive increasing attention due to high loss, demand, and variations. Citrus loss and waste (CLW) causes differ by stage, e.g., worker availability in farms and inadequate packaging in transportation. The dissertation involves a numerical investigation of an ASC aimed at proposing a new structure to enhance its sustainability performance. This objective will be accomplished by first selecting a Citrus SC in a Mediterranean country as a case study. Second, the study will evaluate several research hypotheses through numerical analyses employing various methodologies. For instance, it commenced by reviewing existing literature, conducting interviews with stakeholders, observing harvesting and transportation activities, constructing a system dynamics simulation model to assess dynamic relationships within the citrus SC, and conducting a Life Cycle Assessment (LCA). The LCA aims to compare and evaluate the environmental impacts of two packaging crates used in citrus transportation and their contributions to CLW. Subsequently, a new citrus SC network aimed at enhancing overall sustainability was proposed. This network design incorporates farms, collection points (CPs), citrus hubs (CHs), and distribution centers (DCs). The proposed network underwent evaluation through several steps. Firstly, the optimization process involved determining the necessary number of CPs and CHs to collect citrus from farms, pack it, and distribute it to the scattered DCs within the case study country. Secondly, CP locations were determined using a dedicated mathematical model, while the number and placement of CHs were identified based on criteria such as minimizing transportation costs and CO2 emissions. Upon identifying the necessary equipment, the Life Cycle Cost (LCC) was employed to assess total costs and their impact on the functional unit (FU) cost for both scenarios: the linear citrus SC and the citrus closed loop SC (CLSC). The results revealed that to enhance sustainability performance at the farm level, farmers should employ enough workers to harvest all citrus before it reaches over-maturity. Additionally, using polypropylene crates for citrus transportation reduced CLW during transportation by 60%. Overall, eliminating sources of loss at the farm improved the self-sufficiency index by 18.9%. The model suggested that deploying 52 CPs and two CHs is the optimal number, resulting in a 65% reduction in CO2 emissions. Furthermore, the cost of the FU decreased by 48% and 54% in the linear citrus SC and citrus CLSC, respectively