Characterization Of Virgin Olive Oils Research Articles

How the Addition of Spices and Herbs to Virgin Olive Oil to Produce Flavored Oils Affects Consumer Acceptance

With the aim to expand the olive oil market to a larger number of consumers who are not familiar with the sensory characteristics of virgin olive oil, the use of novel products known as "flavored olive oils", obtained by adding different kind of spices and aromatic herbs, is spreading in many countries. In order to test consumer acceptability of this type of product, in a country (Tunisia) in which virgin olive oil is regularly consumed, flavored olive oils were prepared by adding aromatic extracts of thyme, oregano, a mix of herbs (used as pizza seasoning), rosemary, and basil to a monovarietal Chemlali virgin olive oil and a consumer test on 206 subjects was performed. Selected quality parameters (free acidity, peroxide number, oxidative stability, specific absorption at K232 nm and K270 nm) were also measured and no significant variations were detected. Slight differences were found concerning the content of minor compounds (chlorophylls, carotenoids and total phenols). On the other hand, notable differences were seen in the profiles of volatile compounds, which appeared to be responsible for the observed variability in consumer acceptance. Although the unflavored oil was more appreciated than the flavored ones, among the latter, thyme flavored olive oil was the most appreciated.

Characterization of virgin olive oils produced with autochthonous Galician varieties

The interest of Galician oil producers (NW Spain) in recovering the ancient autochthonous olive varieties Brava and Mansa has increased substantially in recent years. Virgin olive oils produced by co-crushing both varieties in two different proportions, reflecting the usual and most common practice adopted in this region, have gradually emerged for the production of virgin olive oils. Herein, the sensory and chemical characteristics of such oils were characterized by quality and genuineness-related parameters. The results of chemical analysis are discussed in terms of their effective contribution to the sensory profile, which suggests useful recommendations for olive oil producers to improve the quality of oils. Antioxidant compounds, together with aromas and coloured pigments were determined, and their contribution in determining the functional value and the sensory properties of oils was investigated. In general, given the high levels of phenolic compounds (ranging between 254 and 375mg/kg oil), tocopherols (about 165mg/kg oil) and carotenoids (10–12mg/kg oil); these are oils with long stability, especially under dark storage conditions, because stability is reinforced with the contribution of chlorophylls (15–22mg/kg oil). A major content of phenolic compounds, as well as a predominance of trans-2-hexen-1-al within odor-active compounds (from 897 to 1645μg/kg oil), responsible for bitter sensory notes. This characterization allows to developing new antioxidant-rich and flavour-rich VOOs, when co-crushing with a higher proportion of Brava olives, satisfying the consumers’ demand in having access to more healthy dishes and peculiar sensory attributes.

Has the use of talc an effect on yield and extra virgin olive oil quality?

The maximization of both extraction yield and extra virgin olive oil quality during olive processing are the main objectives of the olive oil industry. As regards extraction yield, it can be improved by both acting on time/temperature of malaxation and using physical coadjuvants. It is well known that, generally, increasing temperature of malaxation gives an increase in oil extraction yield due to a reduction in oily phase viscosity; however, high malaxation temperature can compromise the nutritional and health values of extra virgin olive oil, leading to undesirable effects such as accelerated oxidative process and loss of volatile compounds responsible for oil flavor and fragrance. The addition of physical coadjuvants in olive oil processing during the malaxation phase, not excluded by EC regulations owing to its exclusively physical action, is well known to promote the breakdown of oil/water emulsions and consequently make oil extraction easier, thus increasing the yield. Among physical coadjuvants, micronized natural talc is used for olive oil processing above all for Spanish and Italian olive cultivars. The quality of extra virgin olive oil depends on numerous variables such as olive cultivar, ripeness degree and quality, machines utilized for processing, oil storage conditions, etc. However, the coadjuvants utilized in olive processing can also influence virgin olive oil characteristics. The literature highlights an increase in oil yield by micronized natural talc addition during olive processing, whereas no clear trend was observed as regards the chemical, nutritional and sensory characteristics of extra virgin olive oil. Although an increase in oil stability was reported, no effect of talc was found on the evolution of virgin olive oil quality indices during storage. © 2016 Society of Chemical Industry.

Continuous conditioning of olive paste by high power ultrasounds: Response surface methodology to predict temperature and its effect on oil yield and virgin olive oil characteristics

The purpose of this work is the study of the continuous conditioning of olive paste using High Power Ultrasounds (HPU) previous to malaxation, and its effect on extraction yield and Virgin Olive Oil (VOO) characteristics. For this purpose a laboratory scale device for HPU treatment experiments was developed.The HPU induced an instantaneous heating of olive paste until 28 °C whereas it took 20–30 min in the traditional malaxation condition. The temperature increase depended on olive characteristics, olive paste flow rate and HPU intensity. A response surface model was carried out to predict the olive paste temperature for the variables identified previously. The sonication treatment improved the oil yield and gave higher extractability than conventional malaxation. The HPU treatment did not cause alteration on VOO quality indexes and composition. Olive oil volatile compounds related with oxidation mechanisms showed lower concentration for VOOs from HPU treated olive paste.

Sodium chloride compared to talc as processing aid has similar impact on volatile compounds but more favorable on ortho‐diphenols in virgin olive oil

The possibility of improvement of olive paste extractability by addition of talc or NaCl (1, 2, and 3% mass ratio in olive paste), or their combinations (“talc 1.5% + NaCl 1.5%”; “talc 1% + NaCl 2%”; “talc 2% + NaCl 1%”), was investigated on a laboratory scale. Volatiles in oil samples were determined by headspace solid‐phase micro‐extraction with GC‐MS, while ortho‐diphenols were assessed by solid phase extraction and UV‐VIS spectrophotometer. Significantly higher extractability of oil (from 25 to 29% compared to control, p < 0.05) was obtained by 3% of talc or NaCl and their combinations in mass ratio 1:2 or 2:1. At 3% addition level, no significant decrease of C6 aldehydes was observed, while significant increase of C6 alcohols (talc or salt) as well as of C5 compounds and terpenes (salt) occurred. Mass ratio of ortho‐diphenols in oil was not influenced by talc, while NaCl led to significantly higher values compared to control (by 10–15%, p < 0.05).Practical applications: The influence of processing aids on characteristics of virgin olive oil has mainly been evaluated through the standard chemical quality parameters, while limited information about desirable volatile compounds of thus obtained extra virgin olive oils has been published so far. The results of this research show that NaCl can be used not only as a tool for enhancing the extractability, but also as a means for improving the nutritional value of virgin olive oils from cultivars which generally show low levels of hydrophilic phenols.The efficiency of talc and NaCl (processing aids acting on the basis of physical principles) in improvement of so‐called difficult olive paste extractability is similar, but the advantages of NaCl are less pronounced changes of compounds responsible for fruity aroma, as well as increase of ortho‐diphenols, compounds known for their antioxidant activity and health‐promoting properties.

Continuous high power ultrasound treatment before malaxation, a laboratory scale approach: Effect on virgin olive oil quality criteria and yield

Continuous application of high power ultrasound (HPU) on olive paste previous to malaxation at laboratory scale for virgin olive oil (VOO) extraction and its effect on process yield and the VOO quality have been studied. For the VOO samples, we determined the quality indices (free acidity value, peroxide value, K232, K270), bitterness, volatile composition, phenolic content (total and biophenols), tocopherol content, and pigments.The application of ultrasound induced a quick heating of the paste from 20 to 28°C. The sonication treatment improved the industrial oil yield by 1% and the oil extractability by 5.74%. Moreover the HPU treatment did not cause changes in the quality indices, fatty acid composition and volatile aromatic compounds of the VOO. Furthermore the fat autoxidation process was not accelerated by this treatment. Meanwhile oil obtained from olive pastes treated with HPU showed higher content of tocopherol, chlorophylls and carotenoids whereas a reduction in phenolic content and bitterness index was observed.Practical applications: The high power ultrasound (HPU) treatment of olive paste, before malaxation during the virgin olive oil (VOO) elaboration process, can improve the oil extraction yield without alteration of its quality parameters. The olive paste instantaneous heating observed with the HPU can allow the reduction of the malaxation step duration. The results obtained nowadays at laboratory scale are promising for the possibility of the continuous HPU treatment introduction in the olive oil elaboration process as aid or alternative to the malaxation. For this purpose further experiment at pilot and industrial scale are needed.Continuous application of high power ultrasound before malaxation and its effect on the oil extractability and virgin olive oil characteristics.

Effect of organic cultivation of Picual and Hojiblanca olive varieties on the quality of virgin olive oil at four ripening stages

In recent years, there has been a remarkable development of organic agriculture worldwide, including in olive cultivation. The objective of this study was to evaluate the physicochemical characteristics and nutritional quality of virgin olive oils extracted from two of the most widespread olive varieties in Spain (Picual and Hojiblanca) at different olive‐ripening stages, grown using organic or conventional methods. The results of this study showed significant differences in the acidity, oxidative stability, tocopherol contents, fatty acid composition and phenol contents of oils from organically and conventionally cultivated olives. However, the variety and the maturity stage of the olives had a greater effect on the physico‐chemical and nutritional parameters than whether the cultivation method was organic or conventional. Due to the growing interest in organic olive oil in the national and international markets, more studies that analyse the effect of organic cultivation on the quality of olive oil are required.This study evaluates the quality characteristics of virgin olive oils extracted from two of the most widespread olive varieties in Spain (Picual and Hojiblanca) at different olive‐ripening stages, grown using organic or conventional methods. The results showed significant differences in the acidity, oxidative stability, tocopherol contents, fatty acid composition and phenol contents of oils from organically and conventionally cultivated olives.

Consumer discrimination of Chemlali and Arbequina olive oil cultivars according to their cultivar, geographical origin, and processing system

The chemical composition and consumer preferences according to consumer characteristics of virgin olive oils (VOOs) from “Chemlali” and “Arbequina” cultivars were studied in relation to processing system and geographical origin. Statistical analyses revealed significant differences (p < 0.05) among cultivars in % free acidity, K270, and OSI values, pigments, and antioxidant content and in some FAME content. Significant differences were also found according to the processing system in terms of some quality indices, pigments, antioxidant compounds, and OSI values. The effect of processing system on fatty acid composition was almost not significant except for some of them. The effect of the geographical origin was different in relation to the cultivars: For “Chemlali” cultivar, it was significant (p < 0.05) in all studied parameters except for acidity and total polar phenol content. However, for “Arbequina”, the effect was significant (p < 0.05) for K232, pigments, antioxidant compounds and fatty acid composition except for margaric, margaroleic, linolenic, arachidic, and behenic fatty acids. Consumers were able to discriminate between cultivars with more preference for “Arbequina” oil, but only in case of “Chemlali” they could discriminate between the oils from different locations, with significantly more consumer liking for oils from Sidi Bouzid and Sawef. However, they were not able to discriminate between the processing systems.A session of sensory analysis that shows consumer preferences according to consumer characteristics. Consumer preferences are defined as the subjective (individual) tastes and flavors, as measured by the satisfaction that a consumer derives from the consumption of different goods, in this study, the Virgin Olive Oil (VOO). VOO sensory analysis permits the consumer to rank the different oils according to the levels of satisfaction they give the consumer.

Physicochemical and sensory characteristics of virgin olive oils in relation to cultivar, extraction system and storage conditions

This research was carried out to evaluate the effects of variety, extraction system and storage conditions such as packaging type and temperature variation on the quality of virgin olive oil. Several parameters were studied, namely, quality indices, polyphenols, tocopherols, volatile compounds and sensory properties. Thus, two olive varieties Chemlali (Tunisia) and Coratina (Italy) were selected. The olive oils were extracted by different industrial processes (super press, dual and triple phase decanter) then stored in the established conditions (ambient and refrigerator temperature) in the following packaging materials: clear and dark glass bottles and metal bottles. The oils were analyzed before and after being stored for 9months. Principal Component Analysis and Graphical Modeling were applied to fully explore the influence of the studied factors. Results revealed that among samples, oils from Coratina cultivar were the richest in γ-tocopherol while Chemlali oils contained the highest amount of Δ-tocopherol. Quality indices namely K232 and K270 values were mainly influenced by the storage date and packaging material. Meanwhile, free acidity and peroxide value were mainly influenced by the extraction system. Concerning tocopherols, α-tocopherol content was mainly influenced by the packaging material, β-tocopherol was mainly affected by the storage date, for γ-tocopherol content the main influencing factor was the cultivar whereas for Δ-tocopherol the main influencing factor was the extraction system. Regarding volatile compounds their amounts were influenced mainly by the storage date, that was influenced by the packaging material, where a considerable decrease was observed after storage which was reflected by the change of sensory characteristics of stored oils: loss of positive attributes fruitiness, bitterness and pungency and onset of defects which were mainly influenced by the storage date (fruity and bitter attributes), packaging material (pungent, rancid and fusty attributes) and extraction system (musty attribute).

Mass spectrometry to evaluate the effect of the ripening process on phenols of virgin olive oils

SummaryA global approach has been developed to study the influence of ripening of olive fruits on the phenolic fraction present in virgin olive oil from different genotypes of olives. For this purpose, a non‐targeted method based on the analysis of phenolic extracts by MS in high resolution mode was applied. The phenolic profiles obtained by liquid chromatography ‐ quadrupole‐quadrupole‐time‐of‐flight (LC‐QqTOF) were compared by statistical multivariate analysis tools such as principal component analysis and heat correlation maps. In overall terms, discrimination was only observed for specific crop dates and ripening index values, which should be ascribed to a strong influence of the genotype. The ripening process of each genotype was also studied to demonstrate the variation of phenolic profile in relation to the ripening index. This study was also extended to a panel of representative phenols appreciated by their health and nutritional properties. The application of omics technologies to plant breeding programs could be considered as one of the main pillars on which improvement of products quality can be supported.Practical applications: Olive oil phenols are of a great interest since they contribute to autoxidation stability, health properties, and organoleptic characteristics of virgin olive oil. These phenols are considered a key to assess virgin olive oil quality. This study is focused on the effect of the ripening process on the phenolic fraction from a metabolomics point of view. This advanced omics technology (foodomics) applied to plant breeding programs can be one of the pillars to improve products quality.

Insight into virgin olive oil secoiridoids characterization by high-resolution mass spectrometry and accurate mass measurements

With the aim to enhance characterization of virgin olive oil (VOO), high resolution mass spectrometry (HRMS) and high resolution tandem mass spectrometry (HRMS/MS), in positive and negative electrospray ionization (ESI) modes, coupled to fused-core reverse phase chromatography, were applied to distinct VOO phenolic extracts after the optimization of chromatographic conditions, ESI and fragmentation parameters. HRMS, but also HRMS/MS resulted fundamental to progress in secoiridoids structural elucidation. The former revealed that the secoiridoid composition of VOO was far more complicated than previously reported, while the latter helped clarify product ion elemental composition allowing new fragmentations, in addition to those reported in the literature, to be put forward. In particular, for the first time, different product ions with the same nominal mass were unequivocally identified in the spectra of secoiridoid compounds, confirming the greater capacity of HRMS/MS to clarify structure than low-resolution MS. Furthermore, and differing from previous studies, the multiple isomers of the main VOO secoiridoids could be differentiated on the basis of their HR product ion spectra in positive mode.

Analytical evaluation of two monovarietal virgin olive oils cultivated in the south of Tunisia: Jemri‐Bouchouka and Chemlali‐Tataouin cultivars

The characterisation of virgin olive oils from two Tunisian cultivars, growing in the Tataouin zone, namely Jemri-Bouchouka, a rare olive cultivar, and Chemlali-Tataouin, was carried out. Several analytical parameters were evaluated; these include quality index, fatty acids, phenolic, chlorophyll, carotenoid, squalene, α-tocopherol compositions and oxidative stability. Jemri-Bouchouka olive oil had the highest value of oleic acid (74.50%) while Chemlali-Tataouin olive oil had the highest value of oleic acid (69.39 %) and also was characterized by a high percentage of palmitic acid (14.75 %) which makes this oil freeze at a low temperature [corrected]. On the other hand, Jemri-Bouchouka oil was characterised by a low phenolic and α-tocopherol content (267.72 mg GAE kg⁻¹ and 278.34 mg kg⁻¹, respectively). Ten phenolic compounds were identified. The main phenols found in the two olive oils were oleuropein aglycon and pinoresinol. All phenolic compounds showed significant correlations with oxidative stability. The analytical parameters of virgin olive oil that were determined in this study were greatly influenced by cultivar.

Cherry leafroll virus: Impact on olive fruit and virgin olive oil quality

AbstractWe performed a survey on the yield, quality, and chemical characteristics of virgin olive oils from two olive varieties in Croatian Istria: Frantoio and Ascolana tenera, on Cherry leafroll virus‐infected and virus‐noninfected trees and on two harvest dates. Free acidity, peroxide value, specific spectrophotometric absorptions at 232 and 270 nm, fatty acid composition, total phenols, o‐diphenols, oil color, and pigments were determined. Infected olives had lower oil yield and maturity index versus healthy ones. Oils from infected fruits had significant lower value of K232 and K270 and very elevated total phenols content compared to those obtained from healthy olives. Infected Frantoio gave a lower content of o‐diphenols than the healthy ones, which is in contrast to infected Ascolana that had higher values. The aim of this study is to determine the chemical changes in virgin olive oils from healthy and infected trees related to virus influence. According to our knowledge, this is the first survey on the possible influence of viruses on olive fruits, oil yield, and virgin olive oil quality.Practical applications: There are only few papers which analyze the influence of viruses on crops (especially influence on wine quality) and their effects on yield or other agronomic parameters. This work evaluates for the first time the impact of Cherry leafroll virus on the quality of virgin olive oil obtained from Frantoio and A. tenera varieties in terms of basic parameters related to the hydrolitic and oxidative status, content in antioxidant compounds, and in pigments as well as in fatty acid composition.

Aroma Characterization of Virgin Olive Oil from Two Turkish Olive Varieties by SPME/GC/MS

Virgin olive oil samples of Ayvalik and Memecik olive varieties from the Aegean region of Turkey were evaluated for their acidity, peroxide, and color values, and the volatile compounds were investigated by using solid phasemicro extraction/gas chromatography/mass spectroscopy (SPME/GC/MS). The acidity of all the samples were found to be between 0.35–1.0% oleic acid and peroxide values of the oil samples ranged between 14–52 meq/O2 kg of oil. The Y, R, and B values of the samples were between 70–73.60, 1.30–4.70, and 0–3.60, respectively. The SPME/GC/MS results have shown that hexanal (5.66–15.48%), 3 hexen 1 ol (3.12–12.1%), cis 3 hexenol (6.15–13.49%), and 9 octadecenoic acid (5.99-16.01%) were observed as the characteristic volatiles for Ayvalik variety, while trans 2 hexanal (8.65–38.09%) and 3 hexen 1 ol acetate (0.97–7.43%) were observed as the characteristic volatiles for Memecik variety.

Characterization of virgin olive oil from Leucocarpa cultivar by chemical and DNA analysis

Leucocarpa is an olive cultivar characterized by small fruits which assume a peculiar ivory-white color when ripe. The aim of this research was to characterize its oil by analyzing some chemical parameters as well as DNA microsatellites. Monovarietal Leucocarpa oils, produced under controlled conditions, were compared for two consecutive years to oils derived from Coratina, an olive cultivar very diffused in Italy. Both the cultivars were grown in the same field. The values of phenolic compounds observed in Leucocarpa oils were quite low and corresponded to those usually found in sweet tasting oils. Also levels of pigments appeared to be low compared to Coratina monovarietal oils. Microsatellite analysis were carried out by using 11 primer pairs and Leucocarpa oils were compared to six monovarietal oils from cultivars diffused in Southern Italy. The primer pairs lead to 213 amplified fragments, with a mean of 7 different alleles per primer, and a power of discrimination ranging from 0.49 to 0.91. A single microsatellite, GAPU103A, was sufficient to distinguish Leucocarpa oil from the other samples. An identification key based on the amplification profile of this microsatellite was set up to distinguish the oils from different cultivars. The assessed DNA microsatellite profile, independent from environmental conditions, could be helpful to verify the authenticity of Leucocarpa oil samples.

Oil composition of advanced selections from an olive breeding program

AbstractFifteen genotypes coming from crosses between the cultivars Arbequina, Frantoio and Picual were selected on the basis of their agronomic characteristics in a breeding program initiated in 1991. In the present work, the main components of the olive oil of these 15 advances selections have been characterized and compared to their genitors. A wide range of variation was observed for all the fatty acids, minor components and related characteristics evaluated, with significant differences between genotypes for all of them except for β‐tocopherol content. These results confirm the strong genetic influence on olive oil quality previously reported on olive oil cultivar evaluations. The values obtained in the selections have extended the range of variation of their three genitors for all the characters evaluated, except for γ‐tocopherol. Selections UC‐I 7‐8, UC‐I 5‐44 and UC‐I 2‐68 showed the highest average values for tocopherols, polyphenol and C18:1 contents, respectively. Finally, multivariate analysis allowed the classification of genotypes in four groups according to their olive oil composition.Practical applications: Olive oil composition is considered one of the most important objectives in breeding programs aiming at obtaining new olive cultivars. In the last decades olive breeding programs are being carried out in the main olive‐producing countries and several new cultivars and advanced selections have been described. The results of this work provide an initial characterization of virgin olive oils of advanced selections coming from crosses between the cultivars Arbequina, Frantoio and Picual and suggest a strong genetic influence on fatty acid composition, several minor components and related characteristics. These results, together with the agronomic characterization of these selections previously reported, will be used for the final selection of the best genotypes to be registered as new cultivars.

BEHAVIOR OF SUPER-INTENSIVE SPANISH AND GREEK OLIVE CULTIVARS GROWN IN NORTHERN TUNISIA

This work was carried out on the characterization of virgin olive oils from Spanish cultivars: “Arbequina,”“Arbequina I-18” and “Arbosana” and Greek one “Koroneiki” in northern Tunisia under high-density planting system. The quality and typicality of the oils were to be ascribed not only to the olive variety but in large part also to zone of plantation so that, the aim of this work was to study the behavior of these varieties and mainly changes in their oil composition under Tunisian pedo-climatic conditions. Analyses of major components (fatty acids and triacylglycerols) and minor ones (pigments and phenolic compounds) were carried out. Oxidative stability, free acidity, peroxide value, ultraviolet characteristics, accumulation and changes in fatty acid levels during fruit ripening were also analysed. Results showed significant differences between oils from the studied cultivars and the majority of the studied analytical parameters were greatly influenced by the cultivar-environment interaction. PRACTICAL APPLICATIONS The use of different cultivars, Spanish or from other countries could be interesting, based on their agronomical as well as their oil composition and sensorial profile. However, before using new cultivars or cultivars from other environments, they must be properly tested. Therefore, we have found that it's judicious to study the behavior of these varieties and mainly changes in their oil composition under Tunisian pedo-climatic conditions.

Changes in virgin olive oil characteristics during different storage conditions

AbstractIn this study we have examined the effect of olive oil storage outdoors on a comprehensive series of quality measures. The conditions used were at the extreme of those encountered during the production of bottle oil. Filtered and unfiltered oils were compared as was the influence of inert gas (nitrogen) in the headspace. Increases in K232, K270 and peroxides over time were very much reduced by inert headspace gas, which also reduced losses of total phenols and oxidative stability. Headspace nitrogen also reduced the rise in unconjugated phenolics as secoiridoid derivatives declined and minimised losses in polyunsaturated fatty acids. The pattern of volatile compounds detected in olive oils stored indoors or outdoors showed subtle differences. Moreover, when stored with air exposure the levels of some negative sensory components such as penten‐3‐ol and hexanal increased while other positives, like trans‐2‐hexenal were reduced. These changes would be expected to reduce quality. Finally, Panel tests were used. All oils lost perceived quality on storage and this was accelerated outdoors while headspace nitrogen slowed the deterioration significantly. Our data show that storage outdoors for 4 months in winter does not reduce olive oil quality significantly and that an inert gas in the headspace is beneficial.Practical applications: The storage of olive oil for bottling is carried out under a variety of conditions. Here we assess the effects of storage outdoors for oils from the main Greek cultivar (Koroneiki) of olive. Detailed analyses of quality (standard measures, different phenolics, lipids and volatiles) as well as Panel tests were used for evaluation. Our data show that, although storage outdoors causes deterioration quicker than indoors, changes are not serious up to 4 months. Furthermore, the use of an inert headspace gas significantly preserved quality both indoors and outdoors. Thus we would strongly recommend the latter measure to producers.

Improvement of phenolic antioxidants and quality characteristics of virgin olive oil with the addition of enzymes and nitrogen during olive paste processing

The evolution of phenolic compounds and their contribution to the quality characteristics in virgin olive oil during fruit processing was studied with the addition of a combination of various commercial enzymes containing pectinases, polygalacturonases, cellulase and β-glucanase with or without nitrogen flush. Olive fruits ( Olea europaea , L.) of the cultivar Megaritiki, at the semi black pigmentation stage of maturity, were used in a 3-phase extraction system in an experiment at industrial scale. The addition of enzymes in the olive paste during processing increased the total phenol and ortho-diphenol contents, as well as some simple phenolic compounds (3,4-DHPEA, p-HPEA) and the secoiridoid derivatives (3,4-DHPEA-EDA and 3,4-DHPEAEA) in olive oil and therefore improved its oxidative stability. Furthermore, enzyme treatment ameliorated the quality parameters of the produced olive oil (acidity and peroxide value) and their sensory attributes. The use of additional N2 flush with the enzyme treatments did not improve the quality parameters of olive oil any further; however it did not affect the concentration of individual and total sterols or most of the fatty acid composition. Consequently, olive paste treatment with enzymes not only improved the quality characteristics of olive oil and enhanced the overall ogranoleptic quality, but also increased the olive oil yield.

Characterization of Virgin Olive Oils (Olea Europaea L.) from Three Main Iranian Cultivars, ‘Zard’, ‘Roghani’ and ‘Mari’ in Kazeroon Region

ABSTRACTThe quality of virgin olive oil of three major Iranian cultivars including ‘Zard’, ‘Roghani’, and ‘Mari’, grown in Kazeroon region located in southern part of Iran, was examined in 2008. There were significant differences among fatty acids content of all three cultivars. ‘Mari’ had the highest oleic acid, and the lowest palmitic acid. Oleic acid to linoleic acid ratio in all studied cultivars was higher than the reported levels in the olive oils from other countries. Results from the quantification of phenolic compounds indicated that ‘Zard’ cultivar had the highest tyrosol and ‘Mari’ had the highest cinamic acid and vanilic acid. The oil of ‘Zard’ had the highest chlorophyll and ‘Roghani’ showed the highest carotenoid content. Results here confirm that there were significant differences (p<0.05) in the features, biochemical characteristics and nutritional value among these cultivars.