Final Report Summary - OILPULSE (Increased virgin olive oil yield and quality by complementing existing and new olive oil mills with pulsed electric field (PEF) technology)
Executive summary:
Olive oil is one of the most important products of the European agro-alimentary sector, and is increasingly recognised by consumers worldwide as a healthy ingredient due to its elevated oleic acid content and the antioxidant properties of its minor components, including phenolic compounds. In Europe, around 2 million tonnes of olive oil are produced each year by around 12 000 olive mills in a sector comprised mainly of small and medium-sized enterprises (SMEs), including olive producers, cooperatives, olive oil mills, refiners, blenders, and distributors, employing 800 000 people in the European Union (EU).
Virgin oil makes up 15 - 26 % by weight of the olive, and its production involves separation of the oil contained in the fruit (within fruit cells called vacuoles) from the solid components (seed, pip and skin) and the natural vegetable water of the olive. Current methods are limited by the balance between process temperature and oil quality. With the known 'cold press' process, quality is maximised but yield is very limited. Heated to 35 degrees of Celsius, oil extraction is maximised but quality decreases. Even in this case, more than 5 % of oil still remains in the waste.
OILPULSE is a European research project, funded under the European Commission (EC)'s Seventh Framework Programme (FP7) with starting date in 2010. The main objective has been to develop an industrial prototype system to overcome existing limitations. It complements existing and new mill equipment with pulsed electric field (PEF) technology. PEF is an emerging food technology that consists in applying electric pulses to food. The electric field produces pores in the cell membranes by application of an electrostatic force and, depending on electric strength, the process is either reversible or irreversible. By using this technology, the extraction process will:
(a) increase virgin olive oil phytonutrient content, improving consumer health benefits and olive oil shelf life;
(b) reduce the temperature of the olive paste during processing to provide energy savings and improved oil quality while retaining yield;
(c) improve yield by increasing the number of cells that release their oil content.
Main features
- use of PEF,
- application in existing and new olive oil mills,
- prototype capacity: 5 tonnes / hour of olive paste (scalable),
- processing temperature: 3 - 8 degrees of Celsius lower than current,
- compliance with EU and international standards.
After the end of the project period the consortium of SMEs decided to continue, on its own, carrying out the essays / trials with the prototype in order to collect enough data for statistical purposes before undertaking the commercial exploitation of the technology. The study is planned to continue for at least one additional olive harvesting. If the good results we have obtained so far are confirmed, the technology will be available by 2014.
Project context and objectives:
Olive oil is a key product of the European agro-alimentary sector, and is increasingly recognised by consumers worldwide as part of a healthy diet due to its elevated oleic acid content, and antioxidant properties.
Around 2 million tonnes of olive oil are produced each year in the EU by mainly SME olive producers, cooperatives, mills, refiners, blenders, and distributors, employing some 800 000 people. The EU is world's major olive oil producer and consumer, but faces increased competition from non-EU Mediterranean and other countries including Argentina, Mexico, South Africa, Australia, and the United States of America (USA), which have large extensions of land suited to high-density cultivation of olives.
Olives contain around 17 - 26 % by weight of oil. Virgin olive oil production involves crushing of the olives and separation of the oil from the solid matter and vegetable water. However, current processes suffer from limitations in olive oil yield and quality, and energy usage. OILPULSE will overcome such limitations by complementing existing and new mill equipment with PEF technology - an emerging food technology, which can be used to improve process yield as a less energy and time consuming alternative to thermal or enzymatic treatment. It is being applied to a wide range of food products at pilot plant scale and also for non-thermal commercial food preservation whilst retaining fresh food characteristics.
The expected benefits of OILPULSE are the following:
(a) increased virgin olive oil yield and increased virgin olive oil phytonutrient content, to improve consumer health benefits and olive oil-shelf life;
(b) reduction of olive paste temperature during processing, to provide energy savings, and improved oil quality whilst retaining yield.
The benefits of the novel OILPULSE technology could also be applied to the mechanical extraction of other edible oils and oils for bio-diesel production.
OILPULSE is based on improving the mass transfer of the process by using PEF technology.
The PEF technique and its applications
PEF is an emerging 'cold' food technology, which can be used to improve process yield as a less energy and time consuming alternative to thermal or enzymatic treatment. It is being applied as cell disintegration and non-thermal food preservation technologies, whilst retaining fresh food characteristics.
How it works
When exposed to PEFs, cell membranes develop pores which may be permanent or temporary, depending on the intensity and treatment conditions. Pore formation increases membrane permeability which results in the loss of cell content or intrusion of surrounding media.
Depending on the electric field strength, either stress induction, improvement of mass transfer or microbial inactivation can be produced in the tissue.
a) Stress induction
At electric field strengths of 0.5 - 1.5 kV / cm and energy levels of 0.5 - 5 kJ / kg of product, cells repair their membranes, so pore formation is reversible, and cell vitality and metabolic activity are recovered within seconds. This provides a potential to induce stress reactions in plant systems or cell cultures and activate the production of secondary metabolites and improve the extractability of intracellular compounds. PEF treatment at low temperatures does not damage enzymes or proteins, thus the potential to extract valuable components is provided. For example, mild reversible treatment of maize germs increased both oil yield and phytosterol content, and mild reversible PEF treatment of olives and soy beans provided increased oil yield and isoflavonoid respectively. Such results indicate eminent potential to develop processing concepts activating cells as 'bioreactors' to produce high quality food with a high concentration of functional constituents.
b) Improvement of mass transfer
At field strengths of 0.7 - 3 kV / cm and energy levels of 1 - 20 kJ / kg, pore formation is irreversible, which has been shown to result in an improvement of mass transfer processes from cellular tissues. This opens the possibility for PEF enhancement or replacement of conventional methods for the disruption of cellular material (e.g. prior to extraction, pressing or drying) such as thermal treatment, mechanical grinding or enzymatic maceration, which require significant amounts of energy or holding times in storage tanks. Using PEF, it is also possible to reduce detrimental effects on product quality in comparison to thermal or enzymatic treatments.
c) Microbial inactivation
At field strengths of 15 - 20 kV / cm and energy levels of 40 - 1 000 kJ / kg of product, PEF can be utilised for the non-thermal inactivation of microorganisms, as a possible alternative to pasteurisation. Yeasts have been shown to be very sensitive to PEF treatment, and the reduction of microbes has been proven in a broad variety of food products, fruit and vegetable juices, model beer as well as milk, liquid egg and nutrient broth.
Additional information
PEF allows continuous operation with very short processing times, which facilitates incorporation in existing processing lines. By adjustment of electric field strength and pulse rate, PEF can deliver a defined degree of tissue permeabilisation, so biological systems can be stimulated in terms of metabolic activity and the recovery of valuable components can be improved. Also, for treatments other than biological inactivation, PEF energy requirements are quite modest.
A comprehensive discussion of PEF applied to food processing may be found in 'Emerging technologies for food processing', Chapter 4: 'Overview of PEF processing for food', ISBN: 0-12-676757-2. It includes numerous references to work undertaken in this field.
Related website: http://www.electroporation.net
Project results:
After a project duration of 28 months and 3 olive seasons, the project consortium has succeed on firstly validating the technology using a small scale pilot plant, and then integrating the PEF technique on a real mill industry.
A small scale pilot plant was specially designed and built by partner HAKKI USTA Mak. San. Tic. Ltd. Sti., Turkey (HKU) following some specific requirements defined by the consortium of mill producers. HKU is a manufacturer of olive oil production plants and equipment, with a strong presence in national and international markets. They employ 190 people and have installed more than 600 olive oil production plants throughout the world. All production is supported with computer-aided design (CAD) and computer-aided manufacturing (CAM) software.
The HKU prototype was fully equivalent to an industrial line, except for having a reduced production capacity of 300 kg / h.
The assays were performed using a SCANDINOVA SYSTEMS AB, Uppsala (Sweden) (SCAN) pulse modulator. SCAN is a world leading manufacturer of reliable, high performance pulse generators ('modulators') for a wide range of applications, including radar, radiotherapy, X-ray, and PEF systems. SCAN is not officially an OILPULSE partner, but their collaboration and technical support have been key aspects for the right execution of the technical goals.
The pilot plant was operative during two consecutive harvestings, during 2010 and 2011 seasons. The project assays were planned and directed by Technische Universitat Berlin, Department of Food, Biotechnology and Food Process Engineering, Germany (TUB). The partner has been working in the area of PEF technology for nearly 20 years gaining a great expertise in this topic.
For the evaluation of the PEF technique, 4T of homogeneous olive batches of different olive types were equally divided in two assays, one to be processed without PEF (control) and the other with treatment. Fresh olives, harvested as late as 24h, mainly Picual, Cornicabra, Arbequina and Manzanilla cacereña were processed. Beside yield measurements, the study also included the quantification of the oil quality produced with PEF and its comparison with controls.
The prototype assessment demonstrated the suitability of the PEF technology for increasing quantity and at the same time preserve the oil quality.
Nevertheless, it was not possible to translate the assay parameters and results directly to industry. In a typical mill plant of medium and large capacity, every machine is accurately tuned to reach the highest possible level of efficiency for each type of operating conditions. For that reason the project also included an industrial demonstration activity, lasting 2 seasons.
The industrial prototype was developed by Centre De Recerca I Innovació de Catalunya S.A. Barcelona, Spain (CRIC). The company is a multidisciplinary research centre specialised in innovative industrial processes, having experience in the olive oil industry. The prototype was successfully installed in Aceites Malagón's mill (MLG). MLG was founded on 23 April 1980 and are dedicated to the production, packaging, and marketing of virgin olive oil. The company is located in a region of traditional mill industries in the centre of Spain. They market extra virgin olive oil under four trade names and different formats. They distribute in Spain and export to Italy (70 % of exports), France and the USA. Their quality management system is ISO 9001:2000 certified. Their olive campaign starts typically with Arbequina olives from mid-November to 10 December, then Picual olives to 25 December, followed by Cornicabra olives to the end of February. They processed 3 000 tonnes of olives in the 2007 - 2008 campaign, producing 660 t of virgin olive oil (i.e. a yield of 22 % by weight).
The Italian olive mill D'Addato Agroalimentare, S.L.C. (ADDATO) offered another possible location for the prototype. The company was founded in 1910, being its production mostly oriented to the highest quality standards (extra virgin) olive oil.
The industrial line where the prototype was installed (MLG) has a capacity of 4 tonnes per hour, averaging above 350 olive tonnes per year. The prototype has been fully operative since the 2011 season. Its integration involved important technical challenges, since the design had to ensure both homogeneous treatment and compatibility with existing mill equipment, with minimum modifications.
During 2 consecutive seasons, the prototype demonstrated the superior performance of the PEF technology. The benefits were quantifiable and engage the Consortium to continue the project after the official end of the grant in February 2013.
The assessment will continue collecting additional data for a complete understanding of the treatment impact on production yield and oil quality. It is expected the evaluation will allow deciding whether the system is cost effective in terms of benefits and investment. The consortium expects to end the study after next seasons and depending on the final results, commercialise the technology.
Potential impact:
OILPULSE will initially target the large group of 'mid and large size' continuous extraction olive oil mills such as end-user SMEs ADDATO and MLG, processing more than 100 tonnes of olives per year. This group represents a significant market segment, and has the will and the capacity to implement emerging technologies such as OILPULSE. The market potential for OILPULSE is estimated above 10 000 olive oil mills in the main EU olive oil producing countries (Spain, Italy, Greece and Portugal).
Furthermore, based on project results, a lower-cost, scaled-down version of OILPULSE could be manufactured by project SMEs at a future date, to address mills processing at 1 - 2 tonnes per hour, and producing around 100 t of olive oil per year.
The objective of the consortium members is the development and commercialisation of OILPULSE systems which use PEFs to increase virgin olive oil yield and quality, and which may be integrated into existing or new olive oil mills.
List of websites: http://oilpulse.cric-projects.com/
OILPULSE Exploitation Board contact details:
Mr Aniceto Gomez: a.gomez@aceitesmalagon.com
Aceites Malagón S.L.
Country: Spain
Tel: +92-680-0024
Olive oil is one of the most important products of the European agro-alimentary sector, and is increasingly recognised by consumers worldwide as a healthy ingredient due to its elevated oleic acid content and the antioxidant properties of its minor components, including phenolic compounds. In Europe, around 2 million tonnes of olive oil are produced each year by around 12 000 olive mills in a sector comprised mainly of small and medium-sized enterprises (SMEs), including olive producers, cooperatives, olive oil mills, refiners, blenders, and distributors, employing 800 000 people in the European Union (EU).
Virgin oil makes up 15 - 26 % by weight of the olive, and its production involves separation of the oil contained in the fruit (within fruit cells called vacuoles) from the solid components (seed, pip and skin) and the natural vegetable water of the olive. Current methods are limited by the balance between process temperature and oil quality. With the known 'cold press' process, quality is maximised but yield is very limited. Heated to 35 degrees of Celsius, oil extraction is maximised but quality decreases. Even in this case, more than 5 % of oil still remains in the waste.
OILPULSE is a European research project, funded under the European Commission (EC)'s Seventh Framework Programme (FP7) with starting date in 2010. The main objective has been to develop an industrial prototype system to overcome existing limitations. It complements existing and new mill equipment with pulsed electric field (PEF) technology. PEF is an emerging food technology that consists in applying electric pulses to food. The electric field produces pores in the cell membranes by application of an electrostatic force and, depending on electric strength, the process is either reversible or irreversible. By using this technology, the extraction process will:
(a) increase virgin olive oil phytonutrient content, improving consumer health benefits and olive oil shelf life;
(b) reduce the temperature of the olive paste during processing to provide energy savings and improved oil quality while retaining yield;
(c) improve yield by increasing the number of cells that release their oil content.
Main features
- use of PEF,
- application in existing and new olive oil mills,
- prototype capacity: 5 tonnes / hour of olive paste (scalable),
- processing temperature: 3 - 8 degrees of Celsius lower than current,
- compliance with EU and international standards.
After the end of the project period the consortium of SMEs decided to continue, on its own, carrying out the essays / trials with the prototype in order to collect enough data for statistical purposes before undertaking the commercial exploitation of the technology. The study is planned to continue for at least one additional olive harvesting. If the good results we have obtained so far are confirmed, the technology will be available by 2014.
Project context and objectives:
Olive oil is a key product of the European agro-alimentary sector, and is increasingly recognised by consumers worldwide as part of a healthy diet due to its elevated oleic acid content, and antioxidant properties.
Around 2 million tonnes of olive oil are produced each year in the EU by mainly SME olive producers, cooperatives, mills, refiners, blenders, and distributors, employing some 800 000 people. The EU is world's major olive oil producer and consumer, but faces increased competition from non-EU Mediterranean and other countries including Argentina, Mexico, South Africa, Australia, and the United States of America (USA), which have large extensions of land suited to high-density cultivation of olives.
Olives contain around 17 - 26 % by weight of oil. Virgin olive oil production involves crushing of the olives and separation of the oil from the solid matter and vegetable water. However, current processes suffer from limitations in olive oil yield and quality, and energy usage. OILPULSE will overcome such limitations by complementing existing and new mill equipment with PEF technology - an emerging food technology, which can be used to improve process yield as a less energy and time consuming alternative to thermal or enzymatic treatment. It is being applied to a wide range of food products at pilot plant scale and also for non-thermal commercial food preservation whilst retaining fresh food characteristics.
The expected benefits of OILPULSE are the following:
(a) increased virgin olive oil yield and increased virgin olive oil phytonutrient content, to improve consumer health benefits and olive oil-shelf life;
(b) reduction of olive paste temperature during processing, to provide energy savings, and improved oil quality whilst retaining yield.
The benefits of the novel OILPULSE technology could also be applied to the mechanical extraction of other edible oils and oils for bio-diesel production.
OILPULSE is based on improving the mass transfer of the process by using PEF technology.
The PEF technique and its applications
PEF is an emerging 'cold' food technology, which can be used to improve process yield as a less energy and time consuming alternative to thermal or enzymatic treatment. It is being applied as cell disintegration and non-thermal food preservation technologies, whilst retaining fresh food characteristics.
How it works
When exposed to PEFs, cell membranes develop pores which may be permanent or temporary, depending on the intensity and treatment conditions. Pore formation increases membrane permeability which results in the loss of cell content or intrusion of surrounding media.
Depending on the electric field strength, either stress induction, improvement of mass transfer or microbial inactivation can be produced in the tissue.
a) Stress induction
At electric field strengths of 0.5 - 1.5 kV / cm and energy levels of 0.5 - 5 kJ / kg of product, cells repair their membranes, so pore formation is reversible, and cell vitality and metabolic activity are recovered within seconds. This provides a potential to induce stress reactions in plant systems or cell cultures and activate the production of secondary metabolites and improve the extractability of intracellular compounds. PEF treatment at low temperatures does not damage enzymes or proteins, thus the potential to extract valuable components is provided. For example, mild reversible treatment of maize germs increased both oil yield and phytosterol content, and mild reversible PEF treatment of olives and soy beans provided increased oil yield and isoflavonoid respectively. Such results indicate eminent potential to develop processing concepts activating cells as 'bioreactors' to produce high quality food with a high concentration of functional constituents.
b) Improvement of mass transfer
At field strengths of 0.7 - 3 kV / cm and energy levels of 1 - 20 kJ / kg, pore formation is irreversible, which has been shown to result in an improvement of mass transfer processes from cellular tissues. This opens the possibility for PEF enhancement or replacement of conventional methods for the disruption of cellular material (e.g. prior to extraction, pressing or drying) such as thermal treatment, mechanical grinding or enzymatic maceration, which require significant amounts of energy or holding times in storage tanks. Using PEF, it is also possible to reduce detrimental effects on product quality in comparison to thermal or enzymatic treatments.
c) Microbial inactivation
At field strengths of 15 - 20 kV / cm and energy levels of 40 - 1 000 kJ / kg of product, PEF can be utilised for the non-thermal inactivation of microorganisms, as a possible alternative to pasteurisation. Yeasts have been shown to be very sensitive to PEF treatment, and the reduction of microbes has been proven in a broad variety of food products, fruit and vegetable juices, model beer as well as milk, liquid egg and nutrient broth.
Additional information
PEF allows continuous operation with very short processing times, which facilitates incorporation in existing processing lines. By adjustment of electric field strength and pulse rate, PEF can deliver a defined degree of tissue permeabilisation, so biological systems can be stimulated in terms of metabolic activity and the recovery of valuable components can be improved. Also, for treatments other than biological inactivation, PEF energy requirements are quite modest.
A comprehensive discussion of PEF applied to food processing may be found in 'Emerging technologies for food processing', Chapter 4: 'Overview of PEF processing for food', ISBN: 0-12-676757-2. It includes numerous references to work undertaken in this field.
Related website: http://www.electroporation.net
Project results:
After a project duration of 28 months and 3 olive seasons, the project consortium has succeed on firstly validating the technology using a small scale pilot plant, and then integrating the PEF technique on a real mill industry.
A small scale pilot plant was specially designed and built by partner HAKKI USTA Mak. San. Tic. Ltd. Sti., Turkey (HKU) following some specific requirements defined by the consortium of mill producers. HKU is a manufacturer of olive oil production plants and equipment, with a strong presence in national and international markets. They employ 190 people and have installed more than 600 olive oil production plants throughout the world. All production is supported with computer-aided design (CAD) and computer-aided manufacturing (CAM) software.
The HKU prototype was fully equivalent to an industrial line, except for having a reduced production capacity of 300 kg / h.
The assays were performed using a SCANDINOVA SYSTEMS AB, Uppsala (Sweden) (SCAN) pulse modulator. SCAN is a world leading manufacturer of reliable, high performance pulse generators ('modulators') for a wide range of applications, including radar, radiotherapy, X-ray, and PEF systems. SCAN is not officially an OILPULSE partner, but their collaboration and technical support have been key aspects for the right execution of the technical goals.
The pilot plant was operative during two consecutive harvestings, during 2010 and 2011 seasons. The project assays were planned and directed by Technische Universitat Berlin, Department of Food, Biotechnology and Food Process Engineering, Germany (TUB). The partner has been working in the area of PEF technology for nearly 20 years gaining a great expertise in this topic.
For the evaluation of the PEF technique, 4T of homogeneous olive batches of different olive types were equally divided in two assays, one to be processed without PEF (control) and the other with treatment. Fresh olives, harvested as late as 24h, mainly Picual, Cornicabra, Arbequina and Manzanilla cacereña were processed. Beside yield measurements, the study also included the quantification of the oil quality produced with PEF and its comparison with controls.
The prototype assessment demonstrated the suitability of the PEF technology for increasing quantity and at the same time preserve the oil quality.
Nevertheless, it was not possible to translate the assay parameters and results directly to industry. In a typical mill plant of medium and large capacity, every machine is accurately tuned to reach the highest possible level of efficiency for each type of operating conditions. For that reason the project also included an industrial demonstration activity, lasting 2 seasons.
The industrial prototype was developed by Centre De Recerca I Innovació de Catalunya S.A. Barcelona, Spain (CRIC). The company is a multidisciplinary research centre specialised in innovative industrial processes, having experience in the olive oil industry. The prototype was successfully installed in Aceites Malagón's mill (MLG). MLG was founded on 23 April 1980 and are dedicated to the production, packaging, and marketing of virgin olive oil. The company is located in a region of traditional mill industries in the centre of Spain. They market extra virgin olive oil under four trade names and different formats. They distribute in Spain and export to Italy (70 % of exports), France and the USA. Their quality management system is ISO 9001:2000 certified. Their olive campaign starts typically with Arbequina olives from mid-November to 10 December, then Picual olives to 25 December, followed by Cornicabra olives to the end of February. They processed 3 000 tonnes of olives in the 2007 - 2008 campaign, producing 660 t of virgin olive oil (i.e. a yield of 22 % by weight).
The Italian olive mill D'Addato Agroalimentare, S.L.C. (ADDATO) offered another possible location for the prototype. The company was founded in 1910, being its production mostly oriented to the highest quality standards (extra virgin) olive oil.
The industrial line where the prototype was installed (MLG) has a capacity of 4 tonnes per hour, averaging above 350 olive tonnes per year. The prototype has been fully operative since the 2011 season. Its integration involved important technical challenges, since the design had to ensure both homogeneous treatment and compatibility with existing mill equipment, with minimum modifications.
During 2 consecutive seasons, the prototype demonstrated the superior performance of the PEF technology. The benefits were quantifiable and engage the Consortium to continue the project after the official end of the grant in February 2013.
The assessment will continue collecting additional data for a complete understanding of the treatment impact on production yield and oil quality. It is expected the evaluation will allow deciding whether the system is cost effective in terms of benefits and investment. The consortium expects to end the study after next seasons and depending on the final results, commercialise the technology.
Potential impact:
OILPULSE will initially target the large group of 'mid and large size' continuous extraction olive oil mills such as end-user SMEs ADDATO and MLG, processing more than 100 tonnes of olives per year. This group represents a significant market segment, and has the will and the capacity to implement emerging technologies such as OILPULSE. The market potential for OILPULSE is estimated above 10 000 olive oil mills in the main EU olive oil producing countries (Spain, Italy, Greece and Portugal).
Furthermore, based on project results, a lower-cost, scaled-down version of OILPULSE could be manufactured by project SMEs at a future date, to address mills processing at 1 - 2 tonnes per hour, and producing around 100 t of olive oil per year.
The objective of the consortium members is the development and commercialisation of OILPULSE systems which use PEFs to increase virgin olive oil yield and quality, and which may be integrated into existing or new olive oil mills.
List of websites: http://oilpulse.cric-projects.com/
OILPULSE Exploitation Board contact details:
Mr Aniceto Gomez: a.gomez@aceitesmalagon.com
Aceites Malagón S.L.
Country: Spain
Tel: +92-680-0024
