Increasing the Content of Olive Mill Wastewater in Biogas Reactors for a Sustainable Recovery: Methane Productivity and Life Cycle Analyses of the Process

Measuring circular economy in olive oil mills: A review of circularity indicators and tools

Circularity assessment and monitoring have become a core research topic in academic societies, as well as a basis for developing economic development measures. Despite the circular economy (CE) being a game-changer for the agro-food sector, little effort has been made to identify its level of circularity. In order to achieve the transition to a CE, stakeholders and industry professionals must be provided with appropriate indicators, tools and methods. Due to the complexity of CE measurement, it is necessary to devise indicators, methods and tools that are tailored to each industry. The objective of this review article is to identify the indicators and tools required for assessing the level of circularity in olive oil mills. This research collected data regarding available CE indicators at the company and product levels, as well as those applicable to the agro-food industry. As a result, a list of indicators appropriate to the needs of olive mills has been developed that could be used to measure the level of implementation of circular practices in this industry. The main conclusion reached is that once indicators are defined, they should be compared or combined with life cycle assessment methodologies to determine their applicability and effectiveness. There is no doubt that olive oil plays a significant economic, environmental and social role throughout the Mediterranean region. Hence, evaluating the CE is essential to demonstrate the effectiveness of current policies.

Resource recovery and valorization of food wastewater for sustainable development: An overview of current approaches

The food processing industry is one of the world's largest consumers of potable water. Agri-food wastewater systems consume about 70% of the world's fresh water and cause at least 80% of deforestation. Food wastewater is characterized by complex composition, a wide range of pollutants, and fluctuating water quality, which can cause huge environmental pollution problems if discharged directly. In recent years, food wastewater has attracted considerable attention as it is considered to have great prospects for resource recovery and reuse due to its rich residues of nutrients and low levels of harmful substances. This review explored and compared the sources and characteristics of different types of food wastewater and methods of wastewater treatment. Particular attention was paid to the different methods of resource recovery and reuse of food wastewater. The diversity of raw materials in the food industry leads to different compositional characteristics of wastewater, which determine the choice and efficiency of wastewater treatment methods. Physicochemical methods, and biological methods alone or in combination have been used for the efficient treatment of food wastewater. Current approaches for recycling and reuse of food wastewater include culture substrates, agricultural irrigation, and bio-organic fertilizers, recovery of high-value products such as proteins, lipids, biopolymers, and bioenergy to alleviate the energy crisis. Food wastewater is a promising substrate for resource recovery and reuse, and its valorization meets the current international policy requirements regarding food waste and environment protection, follows the development trend of the food industry, and is also conducive to energy conservation, emission reduction, and economic development. However, more innovative biotechnologies are necessary to advance the effectiveness of food wastewater treatment and the extent of resource recovery and valorization.

From antiquity to contemporary times: how olive oil by-products and waste water can contribute to health

Since antiquity, numerous advantages of olive oil and its by-products have been recognized in various domains, including cooking, skincare, and healthcare. Extra virgin olive oil is a crucial component of the Mediterranean diet; several of its compounds exert antioxidant, anti-proliferative, anti-angiogenic and pro-apoptotic effects against a variety of cancers, and also affect cellular metabolism, targeting cancer cells through their metabolic derangements. Numerous olive tree parts, including leaves, can contribute metabolites useful to human health. Olive mill waste water (OMWW), a dark and pungent liquid residue produced in vast amounts during olive oil extraction, contains high organic matter concentrations that may seriously contaminate the soil and surrounding waters if not managed properly. However, OMWW is a rich source of phytochemicals with various health benefits. In ancient Rome, the farmers would employ what was known as amurca, a mulch-like by-product of olive oil production, for many purposes and applications. Several studies have investigated anti-angiogenic and chemopreventive activities of OMWW extracts. The most prevalent polyphenol in OMWW extracts is hydroxytyrosol (HT). Verbascoside and oleuperin are also abundant. We assessed the impact of one such extract, A009, on endothelial cells (HUVEC) and cancer cells. A009 was anti-angiogenic in several in vitro assays (growth, migration, adhesion) and inhibited angiogenesis in vivo, outperforming HT alone. A009 inhibited cells from several tumors in vitro and in vivo and showed potential cardioprotective effects mitigating cardiotoxicity induced by chemotherapy drugs, commonly used in cancer treatment, and reducing up-regulation of pro-inflammatory markers in cardiomyocytes. Extracts from OMWW and other olive by-products have been evaluated for biological activities by various international research teams. The results obtained make them promising candidates for further development as nutraceutical and cosmeceutical agents or dietary supplement, especially in cancer prevention or even in co-treatments with anti-cancer drugs. Furthermore, their potential to offer cardioprotective benefits opens up avenues for application in the field of cardio-oncology.

Life cycle and circularity metrics to measure the sustainability of closed-loop agri-food pathways

This work aims to present a methodological proposal based on Life Cycle (LC) methodologies, and circularity performance indicators, to assess closed-loop pathways by providing comprehensive results on economic and environmental impacts generated by agri-food production systems. The methodological approach will be tested on olive oil production systems, one of the most important agri-food chains for Mediterranean countries, whose import and export significance is set to grow in light of the shrinking market supply of seed oils. Some insights for the co-products valorization are provided through the evaluation of the reuse of by-products as a possible resource capable to improve the sustainability of the olive oil farms. The integrated application of three different methodologies, Life Cycle Assessment (LCA), Environmental Life Cycle Costing (ELCC) and Material Circularity Indicator (MCI), enabled comparative evaluation of Extra Virgin Olive Oil (EVOO) production under a linear production model with production under a circular model. The circular scenario was better in most environmental impact categories, registering an improvement in Global Warming Potential (GWP) of nearly 30%. In economic terms, there was a lower production cost for the circular scenario and a lower environmental cost by reducing the use of synthetic products through the reuse of waste products. The circular scenario recorded a higher degree of circularity due to a reduction in virgin raw materials used in the production process and a reduction in non-recoverable waste. The implementation of circular strategies represents one of the possible trajectories to guide the ecological transition, and the proposed methodological framework can support the decisions of both producers and public decision-makers toward more sustainable and efficient production patterns.

A customized multi-cycle model for measuring the sustainability of circular pathways in agri-food supply chains

Circular economy (CE) is claimed to be a promising pathway to achieve the Sustainable Development Goals (SDGs), but a reliable metric is needed to validate closed-loop strategies by measuring sustainability performances together with the degree of circularity. A significant contribution is offered by Life Cycle (LC) scholars in terms of methodological advances and operational tools for different sectors, also those more complex such as the agro-industrial systems that encompass biological and anthropogenic variables at different scales. However, to date, LC methodologies have not yet answered how to model the complexity of circular pathways. LC evaluations are often modelled for cradle-to-grave analyses, while a circularity evaluation would require an extension of the system boundaries to more interconnected life cycles, orienting towards a cradle-to-cradle perspective. This research gap led us to propose a multi-cycle approach with expanded assessment boundaries, including co-products, into a cradle-to-cradle perspective, in an attempt to internalize circularity impacts. The customized LC framework here proposed is based on the Life Cycle Assessment (LCA), the Environmental Life Cycle Costing (ELCC) in terms of internal and external costs, and the Social Life Cycle Assessment (SLCA) in terms of Psychosocial Risk Factor (PRF) impact pathway. The model is designed to be applied to the olive-oil sector, which commonly causes significant impacts by generating many by-products whose management is often problematic. Results are expected to show that the customized LC framework proposed can better highlight the environmental and socioeconomic performances of the system of cycles, allowing CE to deliver its promises of sustainability, as the circularity of materials per se is a means, not an end in itself.

Bibliometric Mapping of Research on Life Cycle Assessment of Olive Oil Supply Chain

The olive oil supply chain and even its individual stages have been extensively investigated through life cycle assessment (LCA) in recent decades. Most practices of the olive oil supply chain have been associated with negative environmental effects, such as soil degradation, carbon dioxide emissions, air and ground pollution, and depletion of groundwater. The current work aimed to perform a bibliometric analysis, through a science mapping approach, coupled with a review on the life cycle assessment (LCA) studies of the olive oil sector, with relevance to the environmental impacts of agricultural and industrial practices of this food sector. A total of 110 documents published in 2008–2021 were analyzed and discussed. More than 78% of documents were released from 2015. The main Scopus categories relating to the topic analyzed were environmental sciences (25%), energy (18%), and engineering (17%). The most productive countries were Italy, Spain, and Greece. The cluster analysis identified three main research topics related to the “agricultural phase”, “oil extraction”, and “waste management and by-product valorization”. Most of the recent publications focused on the application of LCA to evaluate the environmental impact of innovative agricultural practices, sustainable control of parasites and weeds, wastes, and by-products valorization within a circular economy.

Evolution of the Olive Oil Industry along the Entire Production Chain and Related Waste Management

The production of olive oil involves the sustainable management of the waste produced along the entire production chain. This review examines the developments regarding cultivation techniques, production technologies, and waste management, highlighting the goals to be achieved and the most reasonable prospects. The results show that cultivation and production technology have evolved to an almost final solution to meet economic feasibility, keeping the oil’s high quality. Continuous horizontal decanters will coexist with traditional mills in many countries with old olive oil production and consumption traditions. High-quality products have conquered markets, especially in the wealthiest countries. At the same time, the exploitation of dried pomace by solvent extraction is increasingly an obsolete practice. However, waste management is still looking for one or a few reasonable solutions that meet modern society’s constraints. The enhancement of some experienced technologies and the full-scale application of emerging technologies and strategies should solve this problem in the short–medium term. A short discussion is reported on the possibility of unifying the nature and the quality of the waste, whatever the olive oil production method is. Furthermore, modern thermochemical treatment for solid wet organic waste disposal is examined and discussed.

Sustainability of the Olive Oil System

Sustainability is a widely accepted goal across many sectors of our society and, according to new concepts, it includes resilience and adaptive capacity [...].