Olive mill wastes: Biochemical characterizations and valorization strategies (original) (raw)
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An overview on olive mill wastes and their valorisation methods
Waste Management, 2006
Olive mill wastes represent an important environmental problem in Mediterranean areas where they are generated in huge quantities in short periods of time. Their high phenol, lipid and organic acid concentrations turn them into phytotoxic materials, but these wastes also contain valuable resources such as a large proportion of organic matter and a wide range of nutrients that could be recycled. In this article, recent research studies for the valorisation of olive mill wastes performed by several authors were reviewed: second oil extraction, combustion, gasification, anaerobic digestion, composting and solid fermentation are some of the methods proposed. Special attention was paid to the new solid waste generated during the extraction of olive oil by the two-phase system. The peculiar physicochemical properties of the new solid waste, called two-phase olive mill waste, caused specific management problems in the olive mills that have led to the adaptation and transformation of the traditional valorisation strategies. The selection of the most suitable or appropriate valorisation strategy will depend on the social, agricultural or industrial environment of the olive mill. Although some methods are strongly consolidated in this sector, other options, more respectful with the environment, should also be considered.
New Approaches to Olive Mill Wastes Bioremediation
Remediation of olive mill wastewater (OMW) is an important issue associated with olive-oil manufacturing, a widespread activity in the Mediterranean area. This high organic loading effluent contains water, organic acids, high-molecular-weight polyphenols such as tannins, antocyanins and catechins, which are considered to be responsible for its brownish black colour and ecotoxic properties. The composition of OMWs is highly variable with respect to each individual component, depending on the process conditions and on the agricultural specificities. Thus, different approaches are applicable concerning to OMW treatment and valorisation , considering the specificities of its production and in particular the oil extraction process. Besides there are several physical, physico-chemical, biological and combined processes to OMW detoxification, each may represent an opportunity for a specific condition. It is important to explore new possibilities that are both environmentally sustainable an...
Journal of Chemical Technology & Biotechnology, 2009
Valorisation is a relatively new concept in the field of industrial residues management promoting the principle of sustainable development. One of the valorisation objectives regarding food processing by-products, waste and effluents is the recovery of fine chemicals and the production of precious metabolites via chemical and biotechnological processes. This paper identifies and discusses certain directions that seem to advance valorisation, as well as existing limitations that need to be overcome in the food processing sector. A valorisation strategy is exemplified for the wastewaters arising from the olive oil extraction process; the recovery of antioxidants by chemical methods and the fermentative production of enzymes of commercial interest have been reviewed.
Olive Mill Wastewater: Treatment and Valorization
Springer Water. Springer, Cham, 2023
For more than 7000 years, olive oil production and consumption have been an established tradition in the Mediterranean area. Due to its great dietary and nutritional value, the olive oil industry is quickly growing across the world. Its manufacturing takes place in two ways: press extraction (the traditional method) and the continuous three-phase decanter process. Olive oil is extracted from the fruit of the olive and mixed with water to create a paste. Water is used in some of these steps to squeeze out most of the oil from the olive. The resulting paste is then mixed to increase the percentage of available oil. Both methods produce approximately (20%) olive oil, (30%) solid waste (olive husk) and 50% olive mill wastewater. This olive mill wastewater has a low pH and contains high toxic organic loads, which makes it a major environmental issue for countries producing olive oil. This chapter discusses the various approaches used for the mitigation of wastewater contaminants produced by the olive oil industry. Recent research studies which focused on the valorization options for dealing with olive mill waste residues such as animal feed, biofuel and biogas are also discussed.
Environmental Technology & Innovation, 2023
The olive oil production sector generates considerable quantities of liquid by-products (olive-mill wastewater, OMWW) which, if left untreated, can cause detrimental environmental impacts. This study aimed to investigate the influence of the Lebanese geographical origin, harvesting time and processing system and their interactions on the chemical and biological characteristics of these by-products. The results showed that the interaction of all the three studied factors on the chemical composition of OMWW, were highly significant (p<0.001). Furthermore, all the OMWW could be considered as a rich source of natural phenolic and antioxidant compounds. The average Total Phenolic Content in OMWW samples was 807.56 GAE/ kg with significantly higher values for OMWW obtained from the North (1027.7 GAE/ kg) at early harvest (1024.00 GAE/ kg) and using press system (1036.13 GAE/ kg) as compared to the other samples from the South, intermediate and late harvesting time using 3-phases and Sinolea (p<0.05). The overall results of this study shed light on the need to establish a sustainable means of treating the liquid effluents of olive mills. The results can help prioritize the regions in most need for a treatment system based on the values reported, while redirecting our attention to the possibility of valorizing the phenolic contents as potent raw material rather than pollutants, in an aim to enhance sustainable agriculture and help achieve (sustainable development goal) SDG6 for improved water quality by 2030.
Bioremediation and biovalorisation of olive-mill wastes
2009
Abstract Olive-mill wastes are produced by the industry of olive oil production, which is a very important economic activity, particularly for Spain, Italy and Greece, leading to a large environmental problem of current concern in the Mediterranean basin. There is as yet no accepted treatment method for all the wastes generated during olive oil production, mainly due to technical and economical limitations but also the scattered nature of olive mills across the Mediterranean basin.
Applied Sciences, 2021
Olive oil production represents an agro-industrial activity of vital economic importance for many Mediterranean countries. However, it is associated with the generation of a huge amount of by-products, both in solid and liquid forms, mainly constituted by olive mill wastewater, olive pomace, wood, leaves, and stones. Although for many years olive by-products have only been considered as a relevant environmental issue, in the last decades, numerous studies have deeply described their antioxidant, anti-inflammatory, immunomodulatory, analgesic, antimicrobial, antihypertensive, anticancer, anti-hyperglycemic activities. Therefore, the increasing interest in natural bioactive compounds represents a new challenge for olive mills. Studies have focused on optimizing methods to extract phenols from olive oil by-products for pharmaceutical or cosmetic applications and attempts have been made to describe microorganisms and metabolic activity involved in the treatment of such complex and varia...
Antioxidants
In the Rural Development Plan (2014–2020), the European Commission encouraged the conversion and supported the maintenance of organic farming. Organic olive oil (bioEVOO) production involves the use of environmentally sustainable fertilizers and the recycling of olive pomace (Pom) and olive vegetation waters (VW) to reduce the environmental impact of these wastes. An ecofriendly way to recycle olive wastes is to reuse them to extract bioactive compounds. In this study, the total phenolic compounds content, their profile and dosage, the antioxidant action in oil, pomace, and vegetation water was evaluated when the Trichoderma harzianum M10 was used as a biostimulant in agriculture. Two spectrophotometric tests (2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic) acid (ABTS)) evaluated the antioxidant potential of samples, a spectrophotometric method estimated total phenolic content, and an Ultra-High-Performance Liquid Chromatography (UHPLC)–Orb...
Processes
Cultivation of olive trees and olive oil production have been considered as a legacy for the Mediterranean region. This custom represents a very important benefit for many nations in terms of wealth and health. However, huge amounts of by-products and waste are generated during olive oil production. This represents a serious environmental impact on land and water bodies if not properly handled. Olive oil extraction generates two waste streams, a solid waste called pomace and olive mill wastewater (OMWW), which has been considered as highly pollutant and phytotoxic waste. These wastes have high disposal costs and predominantly generated from small-scale enterprises that have limited financial resources to treat them properly before discharge to the environment. Besides being a serious environmental problem, OMWW has potential economic value that remains to be utilized such as: fertilizers, valuable antioxidants agents and fatty acids needed in human diet. Also, Olive pomace is a valu...
New Techniques for Treatment and Recovery of Valuable Products from Olive Mill Wastewater
2018
The olive oil industries produce large quantities of wastewater having an enormous amount of pollutants that provide a deleterious effect on environment drastically if discharged without proper treatment. Despite its treatment throughout the extraction process, this liquid waste still contains a very important oily residue, always considered as a pollutant waste. In this context, a new upgrading technique has been developed for the treatment and valorization of olive mill