At the Interprofesional we are committed to research, development and innovation. Therefore, we are carrying out a series of scientific studies with the main research centres in the country aimed at identifying the main benefits of olive pomace oil for consumers.
Through scientific research, we seek to debunk myths, uphold the quality of one of the best oils in the world, and discover new innovation processes that make possible the production, distribution and consumption of olive pomace oil.
Research centre: Instituto de la Grasa (IG) Food and Technology Research Centre of the Spanish National Research Council (CSIC)
Project summary:
In addition to a fatty acid composition rich in monounsaturated acids and balanced in unsaturated fatty acids like olive oils, olive pomace oil is also characterized by a high content of compounds of nutritional interest, such as sterols, linear and triterpenic alcohols and squalene.
The positive impact of monounsaturated fats in our diet in terms of preventing cardiovascular disease and cancer has been well established and recognized by international food and health agencies. The FDA has stated that daily consumption of approximately 1½ tablespoon (20 grams) of oils containing high levels of oleic acid may reduce the risk of coronary heart disease. (FDA, 2018b) and the European Food Safety Authority has reported that “replacing saturated fats in the diet with unsaturated fats helps maintain normal blood cholesterol levels” (EC, 2012).
In addition, minor components in oils contribute to numerous nutritional benefits. For example, phytosterols or plant sterols can reduce intestinal absorption of cholesterol and subsequently serum cholesterol levels and, therefore, may help prevent myocardial infarction. Squalene is widely used in the cosmetic and pharmaceutical industries and has been attributed anti-cancer and anti-tumor properties. There are many other minor substances in olive pomace oil (carotenoids, aliphatic alcohols, triterpenic acids and others), although due to their low content in the oil and/or low biological activity, the scientific community has paid less attention to them to date.
The general aim of this project is to highlight the added value of using olive pomace oil for frying, analyzing the content and nature of the bioactive compounds originally present in olive pomace oil and after frying, as well as the absorption of these health-promoting compounds in fried foods. Following the research initiated by Dr. Gloria Márquez (also available on this website), this study seeks to establish new scientific proof of the resistance to alteration and the advantages of olive pomace oil in domestic frying of different foods in comparison with oils marketed as the most suitable for frying.
Lead Researcher: Dra. Mª Victoria Ruiz Méndez (Research Scientist CSIC)
Research team:
• Dr. Gloria Márquez-Ruiz (Research Scientist CSIC)
• Dr. Joaquín Velasco Jiménez (Senior Scientist CSIC)
• Ms. Irene Pérez de la Rosa (Specialized Technician)
Profile of the lead researcher:
Mª Victoria Ruiz-Méndez, Research Scientist at CSIC, holds a PhD in Chemistry and is a Specialist in Fats (https://orcid.org/0000-0003-0750-7915). Since 1991 she has overseen the “Experimental extraction and refining plants” at the Instituto de la Grasa – CSIC. Over her scientific career she has focused on studying the composition of oils, optimizing their refining process depending on their subsequent use and defining the best use of the by-products obtained. Added to this, she has centered on implementing improvements in analytical control for the evaluation of the process and products. She has taken part in many projects, financed by both public and private entities, act as Lead Researcher in 30 of them. She has more than 100 national and international publications, including book chapters, as well as a licensed patent. She has presented the findings of her research at 75 scientific conferences and her group has been awarded the Edwin Frankel Prize for the best publication in “Lipid Oxidation and Quality” of the American Oil Chemists’ Society (Salt Lake City, 2016). She has supervised 4 PHDs.
Currently, together with Dr. Joaquín Velasco (https://orcid.org/0000-0003-4206-3037), he co-leads the research group “Lipid modifications in food”, which aims to study the changes in lipid composition and chemical transformations of oils and fat-rich foods during processing and storage. Together with Dr. Gloria Márquez Ruiz, he collaborates on projects in the field of oil refining. This collaboration began with the study “Chemical and nutritional modifications produced during the heating of edible fats, with special reference to refining and frying processes” (1989-1991) and continues today through various national and international projects and contracts.
The research group has extensive experience in fat and oil frying, conducting studies including the evaluation of frying performance, the activity of natural antioxidants in oils and additives such as dimethylpolysiloxane in continuous and batch frying processes, as well as rapid tests to determine the quality of the oils used.
Results:
The findings of this study demonstrate that the frying behavior of olive pomace oil is good. This oil showed levels of polar compounds well below the limit set by the regulation (25%) in frying tests and in fried foods. These values are even lower in terms of actual alteration, i.e. subtracting the content of diglycerides, compounds naturally present in considerable levels in the polar fraction of olive pomace oil and not in seed oils. Olive Pomace Oil shows intermediate stability compared to sunflower and other seed oils and it should be noted that it does not require the addition of the synthetic compound dimethylpolysiloxane (E900), which is present in most of the seed oils marketed for frying.
In the conditions of the continuous and discontinuous frying tests and in the thermoxidation tests, the findings are very satisfactory because:
Foods (2021): Stability of Bioactive Compounds in Olive-Pomace Oil at Frying Temperature and Incorporation into Fried Foods
María-Victoria Ruiz-Méndez 1,* , Gloria Márquez-Ruiz 2 , Francisca Holgado 2 and Joaquín Velasco 1
* Correspondence: mvruiz@ig.csic.es; Tel./Fax: +34-954-61-15-50
Abstract: The stability of minor bioactive compounds in olive-pomace oils (OPOs) was evaluated at frying temperature under the conditions of a thermoxidation test. Bioactive compounds analyzed included squalene, tocopherols, sterols, triterpenic acids and alcohols, and aliphatic alcohols. In order to determine the amount of OPO bioactive compounds incorporated into foods after frying, three different kinds of frozen products were selected, i.e., pre-fried potatoes (French fries), pre-fried battered chicken nuggets, and chicken croquettes (breaded patties), and were used in discontinuous frying experiments. Results obtained in both the thermoxidation and frying studies showed high stability of triterpenic alcohols (erythrodiol and uvaol), oleanolic acid, and aliphatic alcohols, naturally present in OPOs. In all fried foods, the content of lipids increased after frying, as expected, although the extent of absorption of OPOs into fried foods and the exchange with food lipids depended on the food characteristics. Overall, frying with OPOs improved the nutritional properties of all products tested by increasing the level of oleic acid and by the incorporation of squalene, triterpenic acids and alcohols, and aliphatic alcohols, in significant quantities.
Keywords: frying; French fries; nuggets; croquettes; olive-pomace oil; triterpenic alcohols; oleanolic acid; squalene; sterols; tocopherols; aliphatic alcohols.
Research centre: Food and Nutrition Science and Technology Institute – CSIC
Project summary:
Frying is one of the most common culinary techniques and is a widely used practice, both domestically and industrially. It is a very complex process that involves numerous reactions, due to the oxygen in the air, the high temperature and the water coming from the food. The suitability of a frying oil is related, above all, to its resistance to thermal oxidation, and the main variables associated with the oil that influence it are its degree of unsaturation and the nature and content of its minor compounds having protective effects. In addition, there are important differences depending on the type of frying; that is, whether the process is continuous (industrial frying) or discontinuous (domestic frying, in restaurants, fast food establishments, cafeterias, etc.). The behaviour of olive pomace oil in relation to conventional and high oleic sunflower oils has not been evaluated in rigorous and systematic scientific studies. Considering its composition and physiochemical characteristics, this project expects clearly better results for olive pomace oil, due to its high concentrations of oleic acid, than for conventional sunflower oil, even if the latter is rich in antioxidants (tocopherols). With regards to high-oleic sunflower oils whose fatty acid content is similar to that of olive pomace oil, the primary advantage of the latter are its protective frying compounds, such as squalene and phytosterols.
This study aims to provide the necessary scientific basis to demonstrate that olive pomace oil is more suitable for frying than sunflower oils, both conventional and modified “high-oleic sunflower”, in both domestic and industrial frying.
Profile of the principal investigator:
Gloria Márquez Ruiz is a Scientific Researcher at the Food and Nutrition Science and Technology Institute (ICTAN-CSIC), where he has been working since 1986, and her main research focus is the study of frying oils: quality and stability, development of analysis methods, antioxidant activity, etc. Her research in this field has contributed to the development of new analytical methods for the evaluation of alteration compounds formed in frying and quality control, including the validation of rapid methods for their determination in the hospitality sector, small establishments and cafeterias. She has also extensively studied the influence of numerous variables (temperature, surface area / volume of oil, degree of unsaturation of oil, etc.) on the alteration of different oils, and the effectiveness of different antioxidants (synthetic and natural). The major differences found with regards to the type of frying (continuous and discontinuous) and the interactions between food and oil are also topics addressed by Dr. Márquez in the frying area. She has also carried out research on the digestibility of frying oils and new compounds formed in animal specimens, and on the changes these compounds undergo under gastric and intestinal conditions. Dr. Márquez has published 126 scientific articles and 34 book chapters, directed 6 doctoral theses; and participated in 33 competitive national and international projects, and on 16 contracts with industries and private companies. She has presented the results of her research at 87 scientific congresses and has been awarded the Prize for the Best Oral Communication by the American Oil Chemists’ Society (Indianapolis, 1996), the Prize issued by the Brazilian Society of Fats and Oils for her “Contribution to Analytical Knowledge in the Area of Oils and Fats” (Campinas, 2008), the selection of Lipid Technology (Research Highlights) as one of the best scientific publications in 2003 and 2008, and the Edwin Frankel Award, from the American Oil Chemists’ Society (Salt Lake City, 2016), for the best publication in “Lipid Oxidation and Quality”.
Results:
After 7 months of intense lab work at Spain’s Food and Nutrition Science and Technology Institute (ICTAN), attached to the Scientific Research Council (CSIC), it has been shown that Olive Pomace Oil, in comparison to sunflower and high oleic sunflower oils, possesses properties that make it ideal to obtain the healthiest, crunchiest and most golden fried foods. This conclusion was reached after examining three batches of each of these oils, pertaining to different phases of the campaign. All the frying involved potatoes, in every case replicating in the laboratory the continuous (industrial) and discontinuous (domestic) frying modalities. Parameters like the oil’s quality and the modifications that both the oil and the food undergo during frying were analysed.
Its composition, rich in oleic acid and exclusive bioactive compounds, like squalene and beta-sitosterol, furnishes Olive Pomace Oil with special properties having a protective effect for the oil itself, making it longer lasting and more stable, and for health, with beneficial effects on the body.
After the results obtained it was concluded that Olive Pomace Oil performs much better when frying than conventional sunflower oils and other similar ones, and even slightly better than high oleic sunflower oils. All this demonstrates the quality of Olive Pomace Oil and its aptness for use in frying, thanks to its properties, duration and cost-effectiveness.
Foods (2021): Performance of Olive-Pomace Oils in Discontinuous and Continuous Frying. Comparative Behavior with Sunflower Oils and High-Oleic Sunflower Oils.
Francisca Holgado 1, María Victoria Ruiz-Méndez 2, Joaquín Velasco 2 and Gloria Márquez-Ruiz 1*
* Correspondence: gmarquez@ictan.csic.es
Abstract: Frying performance of olive-pomace oils (OPOs) as compared to sunflower oils (SOs) and high-oleic sunflower oils (HOSOs) was studied in discontinuous frying (DF) and continuous frying (CF) for the first time. DF is used in household, restaurants and frying outlets, while CF is used in the food industry. Oil alteration during frying was determined by measurements of polar compounds (PC) and polymers. Fried potatoes were analyzed for oil absorption and alteration, color, and evaluated in an acceptability test. Results for DF showed that all SOs reached 25% PC at the 9th frying operation (FO), whereas HOSOs did between the 17–18th FO and variable results were found for OPOs since initial levels of diacylglycerols were different. Rates of formation of PC or polymers were the lowest for OPOs, thus showing the best performance in DF. Specifically for PC, relative rates of formation were 1.00–1.11, 2.46–2.71 and 1.37–1.41 for OPOs, SOs and HOSOs respectively. In CF, OPOs and HOSOs behaved similarly and better than SOs, although none reached 25% PC after 40 FO. The good performance of OPOs can be attributed to the high monounsaturated-to-polyunsaturated ratio, in common with HOSOs, and the additional positive effect of minor compounds, especially β-sitosterol and squalene.
Keywords: frying; high-oleic sunflower oil; olive-pomace oil; polar compounds; polymers; sunflower oil.
Research centre: Instituto de la Grasa-CSIC
Project summary:
Alzheimer’s disease is the most common cause of dementia, whose prevalence will grow in the coming years, so it is urgent to take preventive and therapeutic measures to address it. This disease is characterised by the cerebrovascular accumulation of protein deposits enriched in amyloid-beta (Aβ) as a consequence of alterations of the blood-brain barrier. More than 60% of plasmatic Aβ is associated with lipoproteins rich in triglycerides, higher in patients with Alzheimer’s disease. These lipoproteins are also responsible for transporting the fat-soluble components of food through the bloodstream.
Microglia act as macrophages residing in the brain and play a crucial role in most neuropathologies, as they are activated after alterations in the homeostasis of the brain are detected, and surround the amyloid plaques in the brain of Alzheimer’s patients. As a result of this activation, a large number of pro-inflammatory markers are released, mediated by alterations in the oxidative state. It is believed that some of the components of the olive pomace oil could modulate the oxidative stress and the inflammatory response in these cells, separately or synergistically.
This study aims to demonstrate that lipoproteins, rich in triglycerides, are capable of activating microglia, but that this activation could be attenuated through the incorporation of olive pomace oil components into these particles, which could prevent the development of Alzheimer’s disease. If so, the results of the project would lay the foundations for the development of new applications for olive pomace oil to health and, in particular, to reduce the risk of the development and progression of Alzheimer’s disease.
Profile of the principal investigator:
Javier Sánchez Perona has been a Senior Scientist at the Instituto de la Grasa-CSIC since 2008, and works on knowledge of the mechanisms involved in the transport and metabolism of lipids in humans, as well as on the impact of dietary fats and lipophilic bioactive compounds on pathophysiological processes. His research has shown that the interaction and intracellular response to postprandial lipoproteins are selective in vascular cells. He also demonstrated that the consumption of olive oil reduces blood pressure in elderly hypertensive patients through changes in the structure of the cell membrane. He has also observed that the changes in the composition of lipoproteins caused by the consumption of olive oil are due, at least in part, to their content of minor bioactive components, modulating metabolic processes in different cell types. He is currently researching the influence of lipid composition in diets on the processes involved in metabolic disorders associated with excess weight and obesity. The results obtained show that the consumption of a Mediterranean-type breakfast favours a lower postprandial lipidemic response in obese individuals, and contributes to maintaining adequate lipid homeostasis in people of normal weight. In addition, the consumption of this type of breakfast stimulates a lesser release of inflammation mediators in people with normal weight, while obese people require previous weight loss to benefit from this effect. The results obtained so far have led to the publication of 70 scientific articles, 2 patents, 14 book chapters and 3 doctoral theses. He has presented the results of his research at multiple scientific forums and congresses, and was awarded the Exxentia of Phytotherapy and Nutrition (2006), IAMED (2007), as well as the Best Young Researcher Award at the 2nd International Symposium on Triglycerides and HDL, (New York, 2005) and the prize for the Best Oral Communication at the II FESNAD Congress (Barcelona, 2010).
The results of the study confirm the initial dual hypothesis harboured. First, it confirmed that TRLs, particles that transport lipid-soluble substances in the bloodstream, have the capacity to activate microglia cells, leading to an inflammatory process. Secondly, it showed that the minor compounds of Olive Pomace Oil, such as oleanolic acid, α-tocopherol and β-sitosterol, can attenuate the activation of microglia.
Therefore, the results suggest that the bioactive compounds in Olive Pomace Oil could have a protective effect against Alzheimer’s disease by diminishing the activation of microglia. In any case, it is essential to carry out a clinical study to determine whether the effects observed are replicable in humans.
Research centre: Food and Nutrition Science and Technology Institute – CSIC
Project summary:
Cardiovascular disease is a highly prevalent pathology in Western societies, responsible for substantial socio-sanitary spending worldwide. Thus, any contribution to progress in possible prevention tools would be of great value, offering the consumer more information about the benefits associated with a healthy lifestyle and diet. The Mediterranean Diet is recognised as an excellent one, characterised by, among other aspects, the consumption of monounsaturated fats, such as olive oil. In the same way, olive pomace oil is a preferred monounsaturated fat also containing a wide range of minor components (triterpene acids and dialcohols, squalene, tocopherols, sterols, aliphatic fatty alcohols and phenolic compounds) featuring potential biological activity, key to maintaining health.
The specific purpose of the project is to assess the potentially beneficial role of olive pomace oil after its consumption in nutritional doses on biomarkers of cardiovascular health and associated pathologies (hypertension, diabetes and obesity), through an intervention involving healthy volunteers and high-risk subjects (hypercholesterolemic), compared to another widely used seed oil. By demonstrating that the consumption of olive pomace oil possesses beneficial health properties, its consumption would be clearly enhanced in our diet, and in the foreign market, in addition to contributing to the prevention and treatment of cardiovascular disease and other risk factors and pathologies highly prevalent in the population.
Principal Investigator: Dr. Raquel Mateos Briz
Profile of the principal investigator:
The principal investigator, Raquel Mateos Briz, has been a Senior Scientist at the Institute of Food and Nutrition Science and Technology (ICTAN-CSIC) since 2009. A member of the Metabolism and Bioactivity of Phytochemicals (BIOCELL) research group, led by Prof. Laura Bravo, she studies the beneficial effects of the bioactive compounds of plant foods, mainly phenolic compounds, on health. The results obtained so far have led to the publication of 92 scientific articles, 3 patents, 110 presentations at national and international scientific conferences, and several book chapters.
Research Centre: Instituto de la Grasa (IG)
Project summary:
Olive Pomace Oil, in addition to a fatty acid composition rich in monounsaturated acids, and balanced in unsaturated fatty acids, as in olive oils, is known for its high content of bioactive compounds, which boast health benefits. The objective of this project is to spotlight the added value that the use of Olive Pomace Oil offers, analysing the content and nature of these compounds before and after frying, as well as their absorption in fried foods.
Through the analysis of 15 batches of Olive Pomace Oil (five per campaign, for three consecutive seasons) the following bioactive and antioxidant compounds will be evaluated: tocopherols, phytosterols, squalene, specific phenolic compounds, alcohols and triterpene acids, and aliphatic fatty alcohols. The samples will also allow for the analysis of regulatory and quality parameters for frying oils, encompassing Rancimat stability, smoke point, polar compounds and polymer percentage indicators.
At the same time, Olive Pomace Oil’s performance in frying will be evaluated relative to that of seed oils, anti-foam seed oils, and mixtures of oils marketed for frying, in both the continuous (industrial) and discontinuous (domestic) frying modes, with a representative variety of high-consumption products: pre-fried, breaded, battered, etc.
Principal investigator: Dra. María Victoria Ruiz Méndez
Research team:
• Dra. Gloria Márquez Ruiz
• Dr. Joaquín Velasco
Profile of the principal investigator:
Mª Victoria Ruiz Méndez, Doctor of Chemical Sciences and Scientific Researcher at the CSIC, has been responsible for the Experimental Extraction and Refining Plant of the Instituto de la Grasa (IG) since 1991. Her scientific career since then has been dedicated to processes of oil extraction, refining and applications, as she has participated in a large number of projects, with more than 100 national and international publications. In relation to the current project, several research contracts have been executed under her direction on olive pomace oils, obtained in two phases, in wet storage, as well as the use of by-products. The objective of these studies has been the characterisation of crude pomace oils to optimise the refining process, and of by-products of particular interest, such as deodorisation distillates. The research group is made up of Dr Gloria Márquez Ruiz and Dr Joaquín Velasco, renowned for their professional experience in the area of refining and frying processes.
Research centre: Institute of Food and Nutrition Science and Technology – CSIC
Project summary:
The objective of the study is to determine the beneficial potential of Olive Pomace Oil on indicators of cardiovascular health and associated pathologies, such as hypertension, diabetes or obesity, in comparison to sunflower oil. In addition, the study aims to evaluate the impact of Olive Pomace Oil’s bioactive compounds. Clinical trials will be carried out on healthy volunteers and in at-risk subjects diagnosed with hypercholesterolemia (blood cholesterol levels of 200 mg / dL).
Principal Investigator: Dr. Raquel Mateos Briz
Profile of the principal investigator:
The principal investigator, Raquel Mateos Briz, has been a Senior Scientist at the Institute of Food and Nutrition Science and Technology (ICTAN-CSIC) since 2009. A member of the Metabolism and Bioactivity of Phytochemicals (BIOCELL) research group, led by Prof. Laura Bravo, she studies the beneficial effects of the bioactive compounds of plant foods, mainly phenolic compounds, on health. The results obtained so far have led to the publication of 92 scientific articles, 3 patents, 110 presentations at national and international scientific conferences, and several book chapters.
Research Centre: Instituto de la Grasa (IG) (Institute for the Study of Fats)
Project summary:
Alzheimer’s Disease (AD) is the most common cause of dementia, whose prevalence is will rise in the coming years, so it is urgent to establish preventive and therapeutic measures. In a previous study it was demonstrated in BV-2 cells that artificial triglyceride-rich lipoproteins (TRL) are able to activate microglia and induce an inflammatory process. In addition, it was shown that some of the minor liposoluble components that can be found in the Olive Pomace Oil simultaneously modulate the oxidative stress and the inflammatory response in microglia. Finally, it was suggested that these results should be replicated in humans after the consumption of Olive Pomace Oil.
This study formulates the hypothesis that human TRLs are capable of activating the microglia and that said activation can be attenuated when these particles are generated after the consumption of Olive Pomace Oil. If so, the results of the project would lay the groundwork for the initiation of clinical trials to demonstrate the efficacy of Olive Pomace Oil on reducing the risk of the development and the progression of Alzheimer’s Disease.
Principal investigator: Javier Sánchez Perona
Profile of the principal investigator:
Javier Sánchez Perona has been a Senior Scientist at the Institute to de la Grasa-CSIC since 2008. He works on knowledge of the mechanisms involved in the transport and metabolism of lipids in humans, as well as on the repercussions of dietary fats and bioactive lipophilic compounds on pathophysiological processes.
The results obtained so far have led to the publication of 70 scientific articles, two patents, 14 book chapters and three doctoral theses, participating in multiple forums and scientific conferences. His work has been recognised on numerous occasions, with the Exxenta Phytotherapy and Nutrition Awards (2006), IAMED (2007), Best Young Researcher awards at the 2nd International Symposium on Triglycerides and HDL, (New York, 2005) and Best Oral Presentation at the II FESNAD Congress (Barcelona, 2010).
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