Influence of Processing Technologies on Olive Oil Chemical Characteristics and Evaluation of Virgin Olive Oil Quality

A special issue of Foods (ISSN 2304-8158). This special issue belongs to the section "Plant Foods".

Deadline for manuscript submissions: closed (26 April 2023) | Viewed by 18694

Special Issue Editor


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Guest Editor
Andalusian Institute of Agricultural and Fisheries Research and Training (IFAPA), Sevilla, Spain
Interests: olive oil; volatile compounds; phenolic compounds; bioactive compounds; antioxidants; olive oil processing; olive oil quality; biochemistry of olive fruit

Special Issue Information

Dear Colleagues,

The influence of the extraction process is crucial in order to get virgin olive oil (VOO) of differentiated and unique quality with the highest yields. Its exceptional nutritional and organoleptic properties have fostered consumer interest in this food. In fact, during the last decade, the search for new sensory nuances has resulted in “early harvest VOO”, and research on their antioxidant compounds, especially phenolic compounds, has given rise to its own nutritional claim. Hence, this increase in the demand for high-quality virgin olive oil continuously stimulates the search for new technologies for olive oil processing, including post-harvest fruit management, extraction of oil, and storage to sale. Essential challenges of VOO extraction are mainly the design and development of equipment to increase the extraction yield and to reduce overall energy and water usage; to automate and reduce the process time, making production more efficient, and a deeper understanding of the complex biological reactions into olive paste that allows modulating the final composition of olive oil and increases outputs. This Special Issue addresses the current aforementioned technological challenges through scientific understanding, essential for achieving tasty, healthy, and sustainable virgin olive oil.

Dr. Araceli Sanchez-Ortiz
Guest Editor

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Keywords

  • olive oil processing
  • innovative technology
  • olive oil quality
  • olive oil characteristics
  • olive oil composition

Published Papers (9 papers)

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Research

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12 pages, 1213 KiB  
Article
Oxygen as a Possible Technological Adjuvant during the Crushing or the Malaxation Steps, or Both, for the Modulation of the Characteristics of Extra Virgin Olive Oil
by Gabriel Beltrán Maza, Abraham M. Gila Beltrán, María Paz Aguilera Herrera, Antonio Jiménez Márquez and Araceli Sánchez-Ortiz
Foods 2023, 12(11), 2170; https://doi.org/10.3390/foods12112170 - 27 May 2023
Cited by 1 | Viewed by 1160
Abstract
In commercial terms, Extra Virgin Olive Oil (EVOO) is considered an exceptional food with excellent sensory and nutritional quality due to its taste, odor, and bioactive compounds; as such, it is of great health interest. This quality can be affected by the oxidative [...] Read more.
In commercial terms, Extra Virgin Olive Oil (EVOO) is considered an exceptional food with excellent sensory and nutritional quality due to its taste, odor, and bioactive compounds; as such, it is of great health interest. This quality can be affected by the oxidative degradation, both chemical and enzymatic (the activity of oxidative, endogenous enzymes from the polyphenol oxidase and peroxidase olive fruit type), of essential components during the extraction and conservation of EVOO. In the bibliography, oxygen reduction during the malaxation process and oil storage has been studied in different ways. However, research concerning oxygen reduction in the crushing of the olive fruit or the malaxation of the paste, or both, in the “real extraction condition” is scarce. Oxygen reduction has been compared to control conditions (the concentration of atmospheric oxygen (21%)). Batches of 200 kg of the olive fruit, ‘Picual’ cultivar, were used and the following treatments were applied: Control (21% O2 Mill–21% O2 Mixer), “IC-NM”: Inerted crushing -Normal malaxation (6.25% O2 Mill-21% O2 Mixer), “NC-IM”: Normal crushing-Inerted malaxation (21% O2 Mill-4.39% O2 Mixer) and “IC-IM”: Inerted crushing -Inerted malaxation (5.5% O2 Mill-10.5% O2 Mixer). The parameters of commercial quality covered by regulation (free acidity, peroxide value and absorbency in ultra-violet (K232 and K270)) did not suffer any change concerning the control, and so the oils belong to the commercial category of “Extra Virgin Olive Oil”. The phenolic compounds of the olives involved in the distinctive bitter and pungent taste, health properties, and oxidative stability are increased with the downsizing amounts of oxygen in the IC-NM, NC-IM, and IC-IM treatments with an average of 4, 10, and 20%, respectively. In contrast, the total amount of volatile compounds decreases by 10–20% in all oxygen reduction treatments. The volatile compounds arising from the lipoxygenase pathway, which are responsible for the green and fruity notes of EVOO, also decreased in concentration with the treatments by 15–20%. The results show how oxygen reduction in the milling and malaxation stages of olive fruit can modulate the content of phenols, volatile compounds, carotenoids, and chlorophyll pigments in the EVOO to avoid the degradation of the compound with sensorial and nutritional interest. Full article
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20 pages, 1360 KiB  
Article
Effect of Controlled Oxygen Supply during Crushing on Volatile and Phenol Compounds and Sensory Characteristics in Coratina and Ogliarola Virgin Olive Oils
by Gianluca Veneziani, Diego L. García-González, Sonia Esposto, Davide Nucciarelli, Agnese Taticchi, Abdelaziz Boudebouz and Maurizio Servili
Foods 2023, 12(3), 612; https://doi.org/10.3390/foods12030612 - 01 Feb 2023
Cited by 3 | Viewed by 1785
Abstract
In virgin olive oil industries, the technological choices of the production plant affect the biochemical activities that take place in the olives being processed throughout the entire process, thereby affecting the quality of the final product. The lipoxygenase pool enzymes that operated their [...] Read more.
In virgin olive oil industries, the technological choices of the production plant affect the biochemical activities that take place in the olives being processed throughout the entire process, thereby affecting the quality of the final product. The lipoxygenase pool enzymes that operated their activity during the first phases of the process need the best conditions to work, especially concerning temperature and oxygen availability. In this study, a system was equipped to supply oxygen in the crusher at a controllable concentration in an industrial olive oil mill at pilot plant scale, and four oxygen concentrations and two cultivars, Coratina and Ogliarola, were tested. The best concentration for oxygen supply was 0.2 L/min at the working capacity of 0.64 Ton/h. Further, using this addition of oxygen, it was possible to increase the compound’s concentration, which is responsible for the green, fruity aroma. The effect on volatile compounds was also confirmed by the sensory analyses. However, at the same time, it was possible to maintain the concentration of phenols in a good quality olive oil while also preserving all the antioxidant properties of the product due to the presence of phenols. This study corroborates the importance of controlling oxygen supply in the first step of the process for process management and quality improvement in virgin olive oil production. Full article
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17 pages, 1547 KiB  
Article
Influence of the Washing Process and the Time of Fruit Harvesting throughout the Day on Quality and Chemosensory Profile of Organic Extra Virgin Olive Oils
by M. Pilar Segura-Borrego, Rocío Ríos-Reina, Antonio J. Puentes-Campos, Brígida Jiménez-Herrera and Raquel M. Callejón
Foods 2022, 11(19), 3004; https://doi.org/10.3390/foods11193004 - 27 Sep 2022
Viewed by 1877
Abstract
In recent years, there has been a growing demand for organic extra virgin olive oils (OEVOOs) as quality products with greater added value. The aim of the present work was to determine whether the washing process and time of harvesting (morning or afternoon) [...] Read more.
In recent years, there has been a growing demand for organic extra virgin olive oils (OEVOOs) as quality products with greater added value. The aim of the present work was to determine whether the washing process and time of harvesting (morning or afternoon) plays an important role in the quality of Picual OEVOOs by studying quality parameters (degree of acidity, peroxide value, K232, K270, oxidative stability), and volatile and sensory profiles. Olive fruits were harvested at three maturity stages and within each phase at two times of the day (morning and afternoon). Then, samples were divided into two blocks (washed and unwashed). Volatile profile was obtained by headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS). Regarding the physicochemical quality parameters, sensory and volatile profiles, there were no differences between the oils produced under the two treatments applied (washed/non-washed). However, the time of harvesting (morning or afternoon) did influence the volatile and sensory profile, with higher values in the oils obtained from fruits harvested in the morning, being statistically significant for the families of aldehydes, hydrocarbures and lactones. Besides, the olives harvested during the mornings gave rise to oils with higher values in the green and apple fruit attributes. Full article
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19 pages, 1011 KiB  
Article
Irrigation of Young Olives Grown on Reclaimed Karst Soil Increases Fruit Size, Weight and Oil Yield and Balances the Sensory Oil Profile
by Maja Jukić Špika, Davor Romić, Mirella Žanetić, Monika Zovko, Tatjana Klepo, Frane Strikić and Slavko Perica
Foods 2022, 11(18), 2923; https://doi.org/10.3390/foods11182923 - 19 Sep 2022
Cited by 2 | Viewed by 1526
Abstract
The influence of different irrigation regimes on olive fruit morphological parameters and on the quantity and quality (marketable indices, phenolic content, fatty acid composition, and sensory profile) of virgin olive oil (VOO) obtained from the Croatian cultivar Oblica, grown on an extremely rocky [...] Read more.
The influence of different irrigation regimes on olive fruit morphological parameters and on the quantity and quality (marketable indices, phenolic content, fatty acid composition, and sensory profile) of virgin olive oil (VOO) obtained from the Croatian cultivar Oblica, grown on an extremely rocky and dry reclaimed karst soil, was studied over three years. Four treatments were applied: rain-fed and three treatments calculated as 50%, 75%, and 100% of the crop’s irrigation requirement (Irr). Principal component analysis separated growing seasons (GS) that differed in precipitation. In the 2016 season, which had a low number of fruits per kilogram and provided a higher amount of balanced VOO with medium to intense bitterness and pungency (rain-fed treatment), the oil yield increased by irrigation (Irr 75 and Irr 100) up to 18%, while unchanged phenolics, bitterness, and pungency were observed for the VOOs obtained. In the drier GS (2017), which under rain-fed conditions had high fruit per kg, smallest fruit sizes, and lowest oil yield, and in which the VOOs had high phenolic content and intense sensory taste attributes, fruit weight, fruit sizes, and oil yield increased by 35% in all irrigation treatments, while phenols, bitterness, and pungency decreased, balancing the sensory profile of the VOOs. The results obtained here led us to conclude that the irrigation of young olives resulted in a positive effect, with the indication that an abundant water supply is more effective in drought conditions. Full article
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13 pages, 621 KiB  
Article
Application of Pulsed Electric Fields to Pilot and Industrial Scale Virgin Olive Oil Extraction: Impact on Organoleptic and Functional Quality
by Alberto Navarro, María-Victoria Ruiz-Méndez, Carlos Sanz, Melchor Martínez, Duarte Rego and Ana G. Pérez
Foods 2022, 11(14), 2022; https://doi.org/10.3390/foods11142022 - 08 Jul 2022
Cited by 13 | Viewed by 1997
Abstract
The quality of virgin olive oil (VOO) is largely determined by the technology used in the industrial process of extracting the oil. Technological innovations within this field aim to strike a proper balance between oil yield and the optimal chemical composition of VOO. [...] Read more.
The quality of virgin olive oil (VOO) is largely determined by the technology used in the industrial process of extracting the oil. Technological innovations within this field aim to strike a proper balance between oil yield and the optimal chemical composition of VOO. The application of pulsed electric fields (PEF) that cause the electroporation of the plant cell membranes favors a more efficient breakage of the olive fruit tissue, which in turn could facilitate the extraction of the oil and some of its key minor components. Pilot-scale and industrial extraction tests have been conducted to assess the effect of PEF technology on the oil extraction yield and on the organoleptic and functional quality of VOO. The best results were obtained by combining the PEF treatment (2 kV/cm) with short malaxation times and a low processing temperature. Under these conditions, PEF technology could decisively improve the oil yield by up to 25% under optimal conditions and enhance the incorporation of phenolic and volatile compounds into the oils. The PEF treatment neither affected the physicochemical parameters used to determine the commercial categories of olive oils, nor the tocopherol content. Similarly, the sensory evaluation of the PEF-extracted oils by means of a panel test did not detect the appearance of any defect or off-flavor. In addition, the intensity of positive attributes (fruity, bitter and pungent) was generally higher in PEF oils than in control oils. Full article
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22 pages, 1755 KiB  
Article
Effect of Different Watering Regimes on Olive Oil Quality and Composition of Coratina Cultivar Olives Grown on Karst Soil in Croatia
by Karolina Brkić Bubola, Šimun Kolega, Šime Marcelić, Zoran Šikić, Ana Gašparović Pinto, Marko Zorica, Dora Klisović, Anja Novoselić, Maja Jukić Špika and Tomislav Kos
Foods 2022, 11(12), 1767; https://doi.org/10.3390/foods11121767 - 15 Jun 2022
Cited by 4 | Viewed by 2808
Abstract
Croatian islands are olive growing areas characterized by poor conditions for olive trees because of karst soil and a precipitation deficiency. Under these conditions, irrigation is a very important factor for constant olive oil production. This paper aims to investigate the effects of [...] Read more.
Croatian islands are olive growing areas characterized by poor conditions for olive trees because of karst soil and a precipitation deficiency. Under these conditions, irrigation is a very important factor for constant olive oil production. This paper aims to investigate the effects of different watering regimes on quantity, sensory and chemical quality and composition of Coratina cv. olive oil obtained from trees grown on ameliorate karst soil during two harvesting years. Olive trees were subjected to rainfed conditions and three different irrigation treatments (T1—deficit irrigation representing the usual producer’s practice, T2—regulated deficit irrigation in respect to phenological stages, T3—full irrigation). Irrigation treatments increased oil yield compared to rainfed conditions (T1 + 58%, T2 + 66% and T3 + 74%, representing average values for both studied years). All olive oil samples were of extra quality. Irrigation led to a decrease in carotenoids, volatiles, polyunsaturated fatty acids and linolenic acid contents, with no difference found among irrigation treatments. Total phenols and secoiridoids concentration was not affected by irrigation, indicating that similar oil quality could be achieved with less demand on the water supply. Obtained results could help producers to define a suitable irrigation management in particular conditions of ameliorate karst. Full article
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18 pages, 2785 KiB  
Article
Characterization and Discrimination of Italian Olive (Olea europaea sativa) Cultivars by Production Area Using Different Analytical Methods Combined with Chemometric Analysis
by Emilia Pucci, Domenico Palumbo, Adriana Puiu, Antonia Lai, Luca Fiorani and Claudia Zoani
Foods 2022, 11(8), 1085; https://doi.org/10.3390/foods11081085 - 09 Apr 2022
Cited by 5 | Viewed by 2571
Abstract
Olives and olive products are particularly important for the national agroindustrial sector, for the aspects related to the production territory (authenticity), and for the link with the Mediterranean Diet. Several studies indicate that the elemental profile of olive and olive products depends on [...] Read more.
Olives and olive products are particularly important for the national agroindustrial sector, for the aspects related to the production territory (authenticity), and for the link with the Mediterranean Diet. Several studies indicate that the elemental profile of olive and olive products depends on the production area in which the olive trees were grown, and the elemental content of the olives can be used as a marker of the production area. In order to confirm this hypothesis, the multi-elemental profile of olive drupes and olive leaves of eleven cultivars arising from two different production areas was evaluated through ICP-MS and ICP-AES techniques. In addition, some leaf samples were analysed by LPAS in order to evaluate the applicability of this new analytical technique for determining the geographic origin. The obtained results, combined with chemometric tools, showed the possibility of discriminating samples according to the production area on the basis of the elemental content, as well as by LPAS. Full article
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15 pages, 486 KiB  
Article
An International Survey on Olive Oils Quality and Traceability: Opinions from the Involved Actors
by Ramón Aparicio-Ruiz, Noelia Tena and Diego L. García-González
Foods 2022, 11(7), 1045; https://doi.org/10.3390/foods11071045 - 05 Apr 2022
Cited by 2 | Viewed by 1936
Abstract
A survey was launched to understand the current problems and sensitivities of the olive oil market through a series of questions clustered around topics related to quality, traceability, regulation, standard methods and other issues. The questions were selected after a series of interviews [...] Read more.
A survey was launched to understand the current problems and sensitivities of the olive oil market through a series of questions clustered around topics related to quality, traceability, regulation, standard methods and other issues. The questions were selected after a series of interviews with different actors to identify those aspects where some disagreement or different points of view may exist. These questions were grouped in topics such as geographical traceability, consumer perception and quality management. The survey was addressed to eight different olive oil actors independently: producers, retailers, importers, exporters, analysts, workers at regulatory bodies, and consumers. Approximately half of the respondents (67.0% for consumers and 56.0% for the rest of olive oil actors) claimed to understand the importance of the protected designation of origin. In fact, the traceability objectives that were selected as the most relevant were those related with geographical traceability (19.3%) followed by the detection of adulteration (15.6%). Most of the respondents (80%) would agree to share data for a common database; however, some concerns exist about the use of these data and the issue of paying to have access to this database. The respondents mostly expressed an affirmative answer concerning the efficiency of panel test (74%) and a negative answer (90%) concerning the proposal of removing from regulation, although 42% agree with their revision for improvement. The opinions on “best before” date and their relationship with quality and the willingness to apply non-targeted methods were also surveyed. Full article
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Review

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20 pages, 1188 KiB  
Review
Co-Extraction Technique Improves Functional Capacity and Health-Related Benefits of Olive Oils: A Mini Review
by Ítala M. G. Marx
Foods 2023, 12(8), 1667; https://doi.org/10.3390/foods12081667 - 17 Apr 2023
Cited by 2 | Viewed by 1852
Abstract
Olive oil, a fundamental component of the Mediterranean diet, is recognized as a functional food due to its health-promoting composition. The concentration of phenolic compounds in olive oil is influenced by various factors such as genetics, agro-climatic conditions, and technological processes. Therefore, to [...] Read more.
Olive oil, a fundamental component of the Mediterranean diet, is recognized as a functional food due to its health-promoting composition. The concentration of phenolic compounds in olive oil is influenced by various factors such as genetics, agro-climatic conditions, and technological processes. Therefore, to ensure an ideal intake of phenolics through the diet, it is recommended to produce functional enriched olive oil that contains a high concentration of bioactive compounds. The co-extraction technique is used to create innovative and differentiated products that promote the sensory and health-related composition of oils. To enrich olive oil, various natural sources of bioactive compounds can be used, including raw materials derived from the same olive tree such as olive leaves, as well as other compounds from plants and vegetables, such as herbs and spices (garlic, lemon, hot pepper, rosemary, thyme, and oregano). The development of functional enriched olive oils can contribute to the prevention of chronic diseases and improve consumers’ quality of life. This mini-review compiles and discusses relevant scientific information related to the development of enriched olive oil using the co-extraction technique and its positive effects on the health-related composition of oils. Full article
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