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Recently, there has been significant exploration into the utilization of food by-products as natural reservoirs of bioactive substances, particularly in the creation of functional foods naturally enriched with antioxidants. Citrus peels represent a viable option for formulating enhanced olive oils that contribute to a healthier diet, due to their bioactive compound content. This study aimed to (i) ascertain the compositional characteristics of Citrus reticulata olive oil (CrOO) and (ii) assess its nutraceutical properties in rats with metabolic disorder induced by 3 weeks of feeding with a high-fat diet (HFD). The results showed a peculiar phytochemical composition, thanks to the contribution of citrus peels, which are excellent bio-products. In addition, it demonstrated HFD-induced weight gain (18 ± 2% for HFD vs. 13 ± 0.9% for CrOO) and showed protective effects on fasting blood glucose levels (90.2 ± 3.8 mg/dL for HFD vs. 72.3 ± 2.6 for CrOO). Furthermore, a reduction in cardiovascular risk (total cholesterol/HDL cholesterol = 5.0 ± 0.3 for HFD vs. 3.8 ± 0.3 for CrOO) and an improvement in myocardial tissue function were observed, as well as a significant reduction in inflammatory mediators such as iNOS, COX-2, and mPGES-1 in aortic vessel tissues, thus preserving endothelial function at the vascular level.

The nutraceutical properties of extra-virgin olive oil (EVOO) can be further improved by the addition of olive leaves during olive pressing. However, while Citrus leaves are rich sources of bioactive substances, no data are available in the literature about the effect of Citrus leaf addition on the nutraceutical and sensorial profiles of olive oil. This study aimed at comparing the chemical and sensorial qualities of olive oils obtained from ripe olives pressed together with either Olea or Citrus spp. (lemon or orange) cryomacerated leaves. General composition parameters as well as major antioxidants and antioxidant activity were measured. A panel test evaluation, as well as headspace volatile characterization (headspace solid phase microextraction, HS-SPME), were also performed. All data were compared with an EVOO extracted from the same olive batch used as control. It was possible to obtain Leaf Olive Oils (LOOs) characterized by a higher ( p < 0.05) content of antioxidants, compared to the control sample, and the highest oleuropein concentration was detected in the olive oil extracted in presence of olive leaf (+50% in comparison with the control). All the LOOs showed a higher smell complexity and the scent of ripe fruit was generally mitigated. Lemon and olive LOOs showed the best smell profile.

The virgin olive oils (VOOs) under examination were from the main Tunisian cultivar 'Chemlali'. Olive fruits used for oil production were stored in plastic containers for four weeks at ambient temperature. Hydrophilic bioactive compounds and volatile profiles of the corresponding oils were analyzed. Chemometric analysis showed that VOO obtained from fruits stored during one week is similar to that of freshly harvested fruits. They preserved their bioactive and volatile molecular markers of freshness with the predominance of the secoiridoid aldehydic form of oleuropeine aglycon, and the C 6 lipoxygenase products. However, VOO obtained from fruits stored for a long time, showed degradation of the derivatives of oleuropeine and ligstroside aglycons, a decrease in the lignan, and flavonoid groups, whereas phenolic acids showed a remarkable increase. The volatile profile was characterized by a decrease in the LOX products, and biosynthesis of the volatile molecular markers of oxidation C 7 -C 10 aldehydes (nonanal, decanal, (Z) and (E)-2-heptenal, (E)-2-octenal, and (E,E)-2,4-heptadienal), and hydrocarbons (n-dodecane, and n-tetradecane). Mono and sesquiterpenes showed also an increase over storage time. Consequently, and in order to avoid deterioration of VOO composition, chemometric analysis showed that the olive fruits should be processed as soon as possible after being harvested, with a maximum storage time of one week., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: The experiment was carried out on olive trees cv. Chemlali, during two successive years (2013/2014). Two irrigation treatments (IT: Trees irrigated with wastewater; TRC: Trees grown under rainfed condition) were combined with two tillage practices (TTS: Trees grown in tilled soil; TNTS: Trees grown in non-tilled soil)., Results: The results of the study showed that wastewater irrigation combined with soil tillage improved the pomological characteristics of olive fruits. The tree yield increase was substantial for IT and TTS. However, most of the identified phenolic compounds, especially oleuropein, mainly accumulated in olive fruits of the TC block (TNTS + TRC), suggesting a marked improvement in the nutritional value of these fruits. Moreover, fruits of TNTS had high contents of sugar compounds, required for the synthesis of the fruit storage material. The study also showed that the agronomic practices affected the amounts of some aromatic compounds responsible for the distinctive flavour notes of olive oil., Conclusion: Agronomic practices may affect considerably the commercial and nutritional values and the sensorial quality of the commodities. © 2017 Society of Chemical Industry., (© 2017 Society of Chemical Industry.)

Heating operation has been applied to Chétoui extra-virgin olive oils (EVOOs) extracted from fruits with several ripening stages (RS). The studied samples, were subjected to microwave and conventional heating. Results showed that heated VOOs after 2.5 h and 7 min of conventional and microwave heating, respectively, gave rise to a drastically decrease of LOX products and allowed the detection of toxic new formed aldehydic volatiles (alkanal: nonanal, alkenals: (Z)-2-heptenal and (E)-2-decenal, and alkadienals: (E.E)-2.4-decadienal), which can be used as markers of VOO degradation. Their abundance in the VOO headspaces depends on their boiling points, the rate of their possible degradation to yield other compounds, on the heating processes and on the rate of macronutrients. The emission rate of the new synthesized volatiles during heating processes was mainly attributed to enzymatic oxidation of some fatty acids. Hexanal, (Z)-2-heptenal, (E)-2-octenal, (E)-2-nonenal, (E,E) and (E,Z)-2,4-decadienal, and (E,E)-2,4-nonadienal, derived from linoleic acid, and heptanol, octanal, nonanal, decanal, (E) and (Z)-2-decenal, (E)-2-undecenal, and (E,E)-2,4-nonadienal, are emitted after degradation of oleic acid. During thermo-oxidation, the ECN 44 (LLO, and OLnO), and the ECN 46 (OLO, and PLO + SLL) compounds decreased, whereas, the ECN 48 (OOO, and PPO), and the ECN 50 (SOO) compounds increased when temperature and heating time increased. The several variations of the studied biochemical compounds depend to the heating processes. Ripening stage of olive fruits can be used as a tool to monitor the emission rate of the aldehydic volatiles, but cannot be used for a chemometric discrimination., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Aroma profile, oxidative stability and quality parameters of virgin olive oil from four cultivars (Chemlali, Chetoui, Koroneiki and Rjim), grown in Rjim Maatoug oasis in southern of Tunisia, were studied for the first time. The olive oil samples were obtained during maturation from a crop season (2012-2013). The results showed the quality parameters, i.e., free fatty acid, UV absorbance at 232 and 270 nm, increases during maturation exceeding the upper limit established by the IOOC norm. Chlorophyll and carotenoid pigments tended to decrease during ripening stages. The trend of oxidative stability, total phenols and Odiphenols exhibited a reduction of antioxidant activity at more advanced stages of maturity. The marks achieved showed that oil quality degradation is due to the great drought of climate: high temperature, high light intensity and low rainfall. Studied aroma profiles of cultivars were also influenced by severe climatic conditions. Twenty-four compounds were characterized, representing 94.8-99.8% of the total volatiles. In all samples, a strong decrease was observed in aldehydes compounds.

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.

The goal of this work was to investigate the impact of the flavoring of some aromatic plants/spices, including rosemary (R), lemon (L) and orange (O) at the concentration of 5% and 35% (w/w) added by 2 methods (conventional maceration and direct flavoring), on quality attributes, chemical changes and oxidative stability of extra virgin olive oil (EVOO). Six flavored oils were obtained (EVOO + O, O + O, EVOO + R, O + R, EVOO + L and O + L). The physicochemical parameters (water content, refractive index, acidity and peroxide value, extinction coefficient, fatty acids, volatile aroma profiles, Rancimat test, phenols and pigments composition) of the flavored oils were investigated. Based on the results obtained, it was observed that flavoring with a conventional process provided increased oxidative stability to the flavored oils, especially with rosemary (19.38 ± 0.26 h), compared to that of unflavored oil. The volatile profiles of the different flavored oils revealed the presence of 34 compounds with the dominance of Limonene. The fatty acid composition showed an abundance of mono-unsaturated fatty acids followed by poly-unsaturated ones. Moreover, a high antioxidant activity, a significant peripheral analgesic effect (77.7% of writhing inhibition) and an interesting gastroprotective action (96.59% of ulcer inhibition) have been observed for the rosemary-flavored oil. Indeed, the flavored olive oils of this study could be used as new functional foods, leading to new customers and further markets. [ABSTRACT FROM AUTHOR]

Olive leaves are rich in antioxidant compounds. During harvest, they reached about 10% of the total weight which can affect the olive oil quality. So, this work aimed to study the effect of adding different amounts of leaves (1, 2, 5, 10 and 20%) during the olive oil extraction of cv. Chemlali. Changes in physico-chemical indices, oil stability, fatty acid composition, antioxidant contents and volatile composition were evaluated. The obtained olive oils with the addition of less than 10% leaves were classified as Extra Virgin Olive Oil (EVOO). Polyphenols and bitterness index were the highest for treatments with addition of less than 10% leaves. Twenty-nine volatile compounds were identified. Total aldehydes and C6 compounds, responsible of the positive attributes, were the most abundant and were strongly affected by the addition of leaves. Olive oils with 2 and 5% added leaves were rich with aldehydes responsible of green and fruity flavor and in polyphenols. [ABSTRACT FROM AUTHOR]

Fruits from the same cultivar of Olea europaea L. cv. Chaaibi were picked at the same ripeness stage and processed quickly across varied environmental conditions in Tunisia. Solid-phase micro-extraction (SPME) coupled with gas chromatography–mass spectrometry (GC–MS) were used to determine the aroma profile of virgin olive oils. The volatile profiling was mostly constituted of compounds from the following chemical classes: esters, aldehydes, alcohols, and hydrocarbons. Significant variances in the percentages of volatile constituents in oils from diverse geographical origins were discovered, with the aldehyde (E)-2-hexenal being the predominant volatile in almost half of the oil samples. The findings imply that, in addition to genetics, growing area impacts aroma composition. Remarkably, the proportions of volatile compounds and fatty acid compositions in oils collected from different growing areas exhibited strong variability. These findings can be utilized to distinguish and describe Chaaibi olive oils from various areas. [ABSTRACT FROM AUTHOR]

The production of extra virgin olive oil (EVOO) flavored with diverse spices, herbs, fruits, and vegetables or natural aromas is believed to provide advantageous properties considering either the high nutritional value or biological activity in addition to the flavoring and industrial aspects. The biological activities including antioxidant and antimicrobial properties of Tunisian EVOO obtained from "Chemlali" variety and mixed with chili pepper were investigated. Molecular analyses, including the detection of twelve olive-infecting viruses and Pseudomonas savastanoi pv savastanoi, were performed to ensure that the samples were obtained from healthy olive trees and EVOO quality was not affected. Quality parameters like free acidity, peroxide number, oxidative stability, and specific absorption at K232 nm and K270 nm were also investigated and no significant variation was revealed. The content of minor compounds such as chlorophylls, carotenoids, and total phenols showed minor changes. However, the profiles of the volatile compounds showed remarkable differences, which appeared to be the main factor for the observed variability in consumer acceptance. The results showed for the first time high quantities of polyphenols and ortho-diphenols. Four colorimetric methods were used for the determination of the antioxidant activity, namely DPPH, ABTS, FRAP, and β-carotene test. Compared to the control, a higher level of antioxidant activity was observed for the flavored EVOO. Furthermore, significant results were obtained in the antimicrobial tests. The quality parameters of the mixture showed no alteration compared to the control. Finally, all the measurements and the chemical characterization gave a scientific basis for food technology innovation of new food products. [ABSTRACT FROM AUTHOR]

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The main objective of this work was to study the effects of foliar biofertilizers on individual volatile profiles and phenolic compounds of olive oil (Olea europaea L. cv. Chemlali). Three foliar biofertilizers were used in two successive application seasons: T1 (rich in nitrogen, phosphorus and potassium); T2 (rich in calcium); and T3 (application of both T1 and T2). Results showed that foliar fertilization with T2 increased the phenolic compound contents (e.g., oleuropein aglycone and decarboxymethyl ligstroside aglycone) of Chemlali olive oil. It also enhanced the levels of many volatile compounds responsible for the good flavor of olive oil such as hexanal. However, T1‐tested fertilizer led to a significant decrease in the content of phenolic compounds, although they seemed to improve significantly the levels of the majority of volatile compounds, especially hexanal. Based on these results, a significant relationship between plant nutrition and quality of oil was observed. Our results demonstrated a potential positive influence on the concentration of sensory quality compounds under T2 (Ca2+‐based fertilizer). This result should be considered in the design of foliar nutrient application management strategies for olive trees. [ABSTRACT FROM AUTHOR]

Extra virgin olive oil is widely consumed because of its nutritional benefits and sensory properties which are very important to be preserved in the product. Therefore, chemically synthesised compounds, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), are widely used as antioxidants in oil products. It is well known that the activity of some micro-organisms able to oxidise free fatty acids can lead to the loss of the stability of the final product. Nevertheless, several researchers have been recently motivated to evaluate the potential of micro-organisms on the production of bioactive compounds. In this paper, headspace solid micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) were used for the characterization and investigation of Fungal Organic Volatile Metabolites (FOVCs) emitted by 14 fungal strains isolated from olives during their pre-processing storage. A wide range of volatile compounds were detected among them, BHT was produced at levels ranging between 0.3 and 13.1%. This compound could be considered for the industry as natural antioxidant to substitute the synthetic ones used for ameliorating the stability of olive oil and other fatty food products. Practical applications: As the pre-processing storage step is inevitable for several practical reasons, inducing the outgrowth of olive microflora (mainly fungi), which critically affect the physiological state of the fruit and thus the quality of the correspondent oil, this paper try to elucidate the potential of these naturally developing strains and their metabolites (FVOCs) of producing bioactive compounds mainly the BHT which could be considered by the industry in order to substitute the synthetic one largely used to improve the stability of olive oil and other food products. Volatiles, when coupled with the power 'omics' technologies represent a new frontier in bio-prospecting. FOVCs profile of 14 fungi strains isolated from olives stored during 2, 5, and 7 days in plastic bags is determinate by HS-SPME-GC-MS. 87 FVOCs are detected representing six groups dominated by the non-terpene derivatives. Interestingly, a compound with particular interest is detected; the Butylated Hydroxytoluene (BHT) is naturally emitted by 11 strains from the 14 isolated fungi at levels ranging between 0.3 and 13.1% (for Aspergillus conicus). A result which could be considered by the industry in order to substitute the synthetic antioxidants largely used to improve the stability of olive oil and other food products. [ABSTRACT FROM AUTHOR]

The present paper reports on the impact of the microbial growth changes, occuring during fifteen days of cv. Chemlali preprocessing storage in different containers representing the common practice during olive processing (plastic bags, reticular bags, and plastic boxes), on olive oil quality. Next, the microorganisms of their microflora (Fungi) were isolated and identified and their effect on olive oil aroma and volatile biogenesis was evaluated by comparing the olive oil volatile profile versus fungal volatile organic compounds. HS-SPME technique was used for volatile component sampling. Virgin olive oil (VOO) chemical quality indices did not show major variations during storage. Olive oil contained novel volatile compounds that could enhance its flavor, but also contained some off-flavor compounds which could reduce its organoleptic characteristics and thus its quality. Results show that olive microflora can contribute to the biogenesis of olive oil volatiles and thus some genera could potentially be used to enhance olive oil aroma. Practical applications The present paper try to assess the potential contribution of fungi in the biogenesis of volatiles found in olive oil. The identification of microorganisms capable of producing volatile compounds would have a great impact; the diverse functions of Fungal volatile organic compounds (FVOCs) can be developed for use in potential biotechnological applications (biofuel, biocontrol, etc.) with greater market value. For olive oil industry applications, some fungal volatile organic compounds are useful for the control of postharvest plant disease; someothers should be explored due to their antioxidant properties. Application of some of the microflora members or even application of enzymes that these microorganisms produce and that contribute to volatile biogenesis could have much to offer in olive oil quality. [ABSTRACT FROM AUTHOR]

The aim of the present work was to investigate the influence of fruit ripening on oil quality and volatile compounds in an attempt to establish an optimum harvesting time for Oueslati olives, the minor olive variety cultivated in Tunisia. Our results showed that many analytical parameters, i.e., peroxide value, UV absorbance at 232-270 nm, chlorophyll pigments, carotenoids and oleic acid contents decreased during ripening, whilst linolenic acid increased. Free acidity remained practically stable with a very slight rise at the highest maturity index. The volatile compounds emitted by the Oueslati olive oil were characterized and quantified by HS-SPME-GC-EIMS. Twenty-three volatile compounds were identified, mainly aldehydes, sesquiterpenes and esters. The results show variations in the volatile fractions and quality parameters of Oueslati extra virgin olive oil obtained at different olive-ripening stages. Fifteen sesquiterpenes were identified for the first time in this cultivar, mainly hydrocarbon derivatives, but also oxygenated ones. On the basis of the quality parameters and volatile fractions studied, the best stage of Oueslati olive fruits for oil processing seems to be at ripeness index about 3.0. Indeed, these results suggested the possibility of using sesquiterpenes for olive authenticity and traceability and demonstrated that the volatile fractions can be used as indicators of the degree of ripening of the olives used to obtain the corresponding virgin olive oils. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of the refined palm oil addition (20%) on the fatty acid and sterol compositions of refined olive oil or refined soya bean oil and also to investigate the formation of total polar compounds and volatile compounds in these oil blends during fifty successive deep-frying sessions of potato fries at 180 °C. The blend of refined olive oil and refined palm oil exhibited a higher chemical stability during the frying process than that of refined soya bean oil and refined palm oil. Indeed, the total polar compounds and volatile compounds formed, especially 2,4-decadienal, were found to be relatively increased in the refined soya bean oil/refined palm oil blend reaching 36.50% and 46.70%, respectively, after fifty deep-frying sessions. Moreover, the degradation of linoleic acid and β-sitosterol was significantly ( P < 0.05) observed for the refined soya bean oil/refined palm oil blend. The results have proven that the proper blending of monounsaturated refined olive oil with refined palm oil increases its stability and hence improves the quality of such olive oil during frying process. [ABSTRACT FROM AUTHOR]

The influence of the extraction system (continuous vs. discontinuous) and the degree of freshness of olives on the chemical composition and the quality of Chemlali and Chétoui virgin olive oil has been studied. Analytical data mainly concerning the volatile and sensory profiles revealed statistically significant differences in relation to the extraction system. All quality indices and sensory characteristics showed statistically significant differences associated with the degree of freshness of fruits. These results further confirm the general consensus that volatile compounds can be very useful as biomarkers of the quality of virgin olive oil and show correlations with the sensory characteristics. [ABSTRACT FROM AUTHOR]

The oils of olive fruits, pulps and seeds from main Tunisian cultivars of olive trees (Chemlali and Oueslati) were extracted at two different indices of maturity. The free acidity, peroxide value, spectrophotometric indices, chlorophyll content, squalene, fatty acids, aroma, and sensory profiles of the oils were analyzed. Fruit and pulp oils are similar in fatty acid compositions, while seed oils have fatty acid profiles that are different from both varieties. For the first time in this work, squalene content in the fruit, pulp, and seed oils was measured by gas chromatography and was found to decrease during maturation. Squalene concentration in the seed oils was lower than that found in fruit and pulp oils. The volatile profiles of twelve Tunisian olive oils obtained from different parts of the fruit were established by solid phase micro-extraction (SPME) coupled with gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Sixty-six compounds were identified and characterized, representing 92.4 and 97.6% of the total volatiles. Principal component analysis showed that olive oil quality is strongly affected by olive cultivar, maturity index and the different olive parts. [ABSTRACT FROM AUTHOR]

Changes in the oxidative status of Chétoui olive oil were monitored to attest the efficiency of some bioactive compounds from aromatic plants to improve the stability of olive oils after a maceration process at different concentrations. Aromatized olive oils were prepared by addition of lemon and thyme extracts at four different concentrations (20-80 g kg of oils) to virgin olive oils. The following parameters were monitored: free fatty acids, peroxide value, ultra violet absorption characteristics at 232 and 270 nm, fatty acid composition and aromatic profiles. After thermo-oxidation processes, the oleic/linoleic acid ratio remained stable (4.5). Oxidative stability slightly decreased during thermo-oxidation processes. The heating of the oils changed their volatile profile and led to the formation of new volatile compounds, such as the two isomers of 2,4-heptadienal after heating at 100 °C or ( E,Z)-2,4-decadienal and ( E,E)-2,4-decadienal after thermo-oxidation at 200 °C. The use of lemon and thyme extracts modified the aromatic and the nutritional value of the olive oil by the transfer of some bioactive compounds, such as limonene and carvacrol. In contrast, the oxidative stability of the product did not change. Furthermore, the aromatized oils may be employed in seasoning and cooking of some foods. [ABSTRACT FROM AUTHOR]

Summary [ABSTRACT FROM AUTHOR]

Abstract: This paper reports a discrimination study based on the antioxidant compounds, oxidative stability, aroma and sensory profiles of virgin olive oils from the main Tunisian cultivars, Chemlali and Chétoui, grown in two different locations, north and south Tunisia, with important differences in altitude, latitude and climatic conditions. There were significant differences between the oils from both cultivars when grown in the different environments. At higher altitude, the oils showed a greater amount of oleic acid, phenols and a higher stability, whilst in the open the oils had higher saturated and linoleic acid content. Aroma profiles were also influenced by the pedoclimatic conditions; hence, oils from the South had the highest level of (E)-2-hexenal and 1-hexanol, whereas varieties from the North were higher in (E)-3-hexenyl acetate and hexyl acetate. In general, and independently of the growing area conditions, oils from Chétoui olives had higher levels of antioxidants, greater oxidative stability, higher antiradical activities and more marked intensity of bitterness. These results can be used to discriminate and to characterise the Chemlali and Chétoui olive oils from each region. [Copyright &y& Elsevier]

The essential oils extracted from the peels of two Tuscany Citrus of the Massa province have been characterised. Moreover, the flavedo of these species has been used in the production of two Citrus olive oils (COOs) obtained with an innovative method in which the citrus peels are cryomacerated and then pressed with the olives. The presence of functional compounds, such as carotenoids, naringenin and minor phenolics, classifies these COOs as nutraceuticals with the potential to develop enriched foods able to promote a healthy diet. Moreover, the increased presence of tyrosol and hydroxytyrosol, compared to the unflavoured oil, further highlights the nutritional value to the two COOs, being these phenolic compounds recognized as good possible therapeutic candidates for the inhibition of neurodegenerative diseases as the Parkinson's disease. In this perspective, the citrus peels, rich in bioactive compounds, have been valued transforming their waste nature in an innovative resource. [ABSTRACT FROM AUTHOR]

Abstract: The analysis of the total lipid fraction from the Sayali variety of olive oil was accomplished in the present investigation. Glyceridic, unsaponifiable and flavour fractions of the oil were isolated and identified using several analytical methods. Chromatographic techniques have proven to be suitable for these determinations, especially capillary gas chromatography. Gas chromatography coupled to mass spectrometry was successfully used to identify sterols, triterpenes alcohols, 4-monomethylsterols, aliphatic alcohols and aroma compounds in our samples. Furthermore, solid phase microextraction was used to isolate volatiles from the total lipid fraction. Results from the quantitative characterization of Sayali olive oil showed that oleic acid (77.4%) and triolein (47.4%) were the dominant glyceridic components. However, the main compounds of the unsaponifiable fraction were β-sitosterol (147.5mg/100g oil), 24-methylene cycloartenol (146.4mg/100g oil) and hexacosanol (49.3mg/100g oil). Moreover, results showed that the aldehydic compounds were the major flavours present in Sayali olive oil. [Copyright &y& Elsevier]

Abstract: 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). [Copyright &y& Elsevier]