Picual Olive Research Articles

Sensory and physicochemical characteristics of Uruguayan picual olive oil obtained from olives with different ripening indexes

The sensory and physicochemical characteristics of olive oil will be mainly influenced by the agronomic conditions of the crop and harvest. Therefore, the results cannot be extrapolated from one region to another. On the contrary, the ripening index (RI) is a factor that can influence the quality of the oils obtained. Picual is one of the four most important olive varieties from Uruguay. This work studied how ripening influences the sensory and physicochemical characteristics of the extra virgin olive oil extracted from the Picual variety olives harvested in Uruguay. A total of 19 samples of olive oils extracted in the Abencor System pilot plant were analyzed. They were obtained from green, medium, and ripened olives from two different harvests (2021 and 2022). All the studied pastes were considered “difficult” due to a high moisture content of over 55%. This was reflected in the low yields of extraction which did not exceed 12.9%. All the oils obtained were characterized as extra virgin from a sensory and physicochemical point of view. Their content of total phenols and oleic acid allows defining Uruguayan Picual oils as “high in total phenols” and “high in oleic acid,” respectively. They were sensory characterized as oils with fruity medium, bitter medium, and pungent medium and green, tomato, banana, and dry fruit aromatic notes. When olives increased ripening, the fruity, bitter, and pungent of the oils and phenol and oleic contents and the oleic/linoleic ratio decreased, and the yield was not modified. This is what makes the Uruguayan olive oil of the Picual variety ideal to be harvested with low RIs.

Effect of Salicylic and Ascorbic Acids Foliar Application on Picual Olive Trees Growth under Water Stress Condition

Effect of Salicylic and Ascorbic Acids Foliar Application on Picual Olive Trees Growth under Water Stress Condition

Enhancement Picual Olive Trees Productivity by Using Potassium Citrate with Gibberellic Acid

Enhancement Picual Olive Trees Productivity by Using Potassium Citrate with Gibberellic Acid

Effect of Silver Nanoparticles, Medium Composition and Growth Regulators on in vitro propagation of Picual Olive Cultivar

Micro-propagation of olive provides the possibility of producing clones of native plants with appropriate attributes and mass production in short period of time, compared to conventional methods. Micropropagation of olive requires optimization of protocols and adaptation to specific cultivars requirements. This experiment was carried out during 2020 and 2021 seasons in tissue culture laboratory of Pomology Department, Faculty of Agriculture, Cairo University in order to evaluate the potential effects of nano silver at (0, 5, 10 and 20 mg L-1) to improve sprouting percentage and shoot growth of Picual olive cv. The effect of nutrient media composition (MS modified, OM and OM modified) and cytokinins (BAP and Zeatin) on multiplication rate and shoot growth were examined. IBA and NAA (2 and 4 mg L) was examined during rooting stage. The obtained results cleared that Silver Nanoparticles (AgNPs) at 5 mg L-1 recorded the highest percentage of bud sprouting, shoot length, number of shoot/explant and number of leaves/ shoot. Olive medium (OM) recorded the highest shoot length, number of shoot/explant and number of leaves/ shoot compared with OM modified and MS modified media. Also, Zeatin at 4 mg L-1 recorded the highest shoot growth parameters during in vitro multiplication stage. During in vitro rooting stage, both the type and concentration of auxins have a significant influence on number of roots, root length and rooting % of Picual olive cultivar. In conclusion, it is recommended that very low concentrations of nano-silver particles be used in plants tissue culture on olive media (OM) supplemented with Zeatin at 4mgL-1.

Effect of Spraying Dolomite Nano-Particles on Growth, Flowering and Fruit Setting of Picual Olive (Olea europaea L.) Cultivar under Water Stress Conditions

Effect of Spraying Dolomite Nano-Particles on Growth, Flowering and Fruit Setting of Picual Olive (Olea europaea L.) Cultivar under Water Stress Conditions

Effect of adding fungal β‐carotene to picual extra virgin olive oils on their physical and chemical properties

Vegetable oils are prone to oxidation, which detracts from their quality and nutritional value, and β-carotene is a major carotenoid with healthy properties. In this work, fungal β-carotene was added to extra-virgin oils from Picual olives in order to prevent their degradation and foster consumption of bioactive substances. The effect of β-carotene was assessed by comparing various quality-related physical and chemical properties of the oils in its presence and absence. The oils were also examined for their response to microwave heating and exposure to light. The fact that no substantial changes in free acidity were observed upon addition of the carotenoid suggests the absence of hydrolysis reactions in the oils. Except for free acidity, all physical and quality-related parameters of extra virgin olive oil were altered by microwave heating and exposure to UV light. The changes, however, were less marked in βC-enriched samples, which suggest that the carotenoid has a protective effect against degradation. Based on the results, natural antioxidants such as β-carotene may provide an effective means for increasing the shelf-life, nutritional value, and resistance to degradation of extra-virgin olive oil. Novelty impact statement Adding β-carotene to olive oil increases its nutritional value and improves oil stability against microwave heating and light exposure. Using carotenoid-enriched olive oils as new functional foods can be useful to increase the daily intake of essential bioactive molecules through human diet, enhance the healthy properties of oils and confer them valuable nutritional assets and additional stability.

Effect of Cultivar Resistance and Soil Management on Spatial-Temporal Development of Verticillium Wilt of Olive: A Long-Term Study.

Verticillium wilt, caused by Verticillium dahliae, challenges olive cultivation and an Integrated Disease Management (IDM) approach is the best-suited tool to combat it. Since 1998, an IDM strategy in an orchard (called Granon, Spain) of the susceptible cv. Picual was conducted by increasing planting density with moderately resistant cv. Frantoio, chemical weed control, and replanting of dead olives with cv. Frantoio following soil solarization. The Verticillium wilt epidemic in Granon orchard was compared to the epidemic in a non-IDM orchard (called Ancla, Spain) with plowed soil and dead Picual olives replanted with the same cultivar. Field evaluations (2012–2013) showed an incidence and severity of the disease as Picual–Ancla > Picual–Granon > Frantoio–Granon. The spatiotemporal dynamics of the Verticillium epidemics from 1998 to 2010 were monitored with digital images using SIG. The annual tree mortalities were 5.6% for Picual olives in Ancla orchard, and 3.1 and 0.7% for Picual and Frantoio olives in Granon orchard, respectively. There was a negative relationship between the mortality of olive trees (%) by the pathogen and the height (m) above sea level. The annual mortality of cv. Picual olives was positively correlated with spring rainfalls. The Index of Dispersion and beta-binomial distribution showed aggregation of Verticillium-dead olives. In conclusion, this IDM strategy considerably reduced the disease in comparison with traditional agronomic practices.

Exploring the Extra-Virgin Olive Oil Volatilome by Adding Extra Dimensions to Comprehensive Two-Dimensional Gas Chromatography and Time-of-Flight Mass Spectrometry Featuring Tandem Ionization: Validation of Ripening Markers in Headspace Linearity Conditions.

Comprehensive two-dimensional gas chromatography (GC×GC) combined with time-of-flight (TOF) MS is the most informative analytical approach for chemical characterization of the complex food volatilome. Key analytical features include separation power and resolution enhancement, improved sensitivity, and structured separation patterns from chemically correlated analytes. In this study, we explore the complex extra-virgin olive oil volatilome by combining headspace (HS) solid-phase microextraction (SPME), applied under HS linearity conditions to GC×GC-TOF MS and featuring hard and soft ionization in tandem. Multiple analytical dimensions are combined in a single run and evaluated in terms of chemical dimensionality, method absolute and relative sensitivity, identification reliability provided by spectral signatures acquired at 70 and 12 eV, and dynamic and linear range of response provided by soft ionization. Method effectiveness is validated on a sample set of oils from Picual olives at different ripening stages. Ripening markers [3,4-diethyl-1,5-hexadiene (RS/SR), 3,4-diethyl-1,5-hexadiene (meso), (5Z)-3-ethyl-1,5-octadiene, (5E)-3-ethyl-1,5-octadiene, (E, Z)-3,7-decadiene and (E, E)-3,7-decadiene, (Z)-2-hexenal, (Z)-3-hexenal and (Z)-3-hexenal, (E)-2-pentenal, (Z)-2-pentenal, 1-pentanol, 1-penten-3-ol, 3-pentanone, and 1-penten-3-one] and quality indexes [(Z)-3-hexenal/nonanal, (Z)-3-hexenal/octane, (E)-2-pentenal/nonanal, and (E)-2-pentenal/octane] are confirmed for their validity in HS linearity conditions. For the complex olive oil volatilome, the proposed approach offers concrete advantages for the validation of the informative role of existing analytes while suggesting new potential markers to be studied in larger sample sets. The accurate fingerprinting of volatiles by HS-SPME operating in HS linearity conditions followed by GC×GC-TOF MS featuring tandem ionization gives the opportunity to improve the quality of analytical data and reliability of results.

Evolution of Bacterial Communities, Physicochemical Changes and Sensorial Attributes of Natural Whole and Cracked Picual Table Olives During Spontaneous and Inoculated Fermentation

Table olives are one of the most well-known traditionally fermented products, and their global consumption is exponentially increasing. In direct brining, table olives are produced spontaneously, without any debittering pre-treatment. Up to date, fermentation process remains empirical and inconstant, as it is affected by the physicochemical attributes of the fruit, tree and fruit management of pro and post-harvest. In the present study, whole and cracked Picual table olives were fermented at industrial scale for 120 days, using three distinct methods (natural fermentation, inoculation with lactic acid bacteria (LAB) at a 7 or a 10% NaCl concentration). Microbial, physicochemical and sensorial alterations monitored during the whole process, and several differences were observed between treatments. Results indicated that in all treatments, the dominant microflora were LAB. Yeasts also detected in noteworthy populations, especially in non-inoculated samples. However, LAB population was significantly higher in inoculated compared to non-inoculated samples. Microbial profiles identified by metagenomic approach showed meaningful differences between spontaneous and inoculated treatments. As a result, the profound dominance of starter culture had a severe effect on olives fermentation, resulting in lower pH and higher acidification, which was mainly caused by the higher levels of lactic acid produced. Furthermore, the elimination of Enterobacteriaceae was shortened, even at lower salt concentration. Although no effect observed concerning the quantitated organoleptic parameters such as color and texture, significantly higher levels in terms of antioxidant capacity were recorded in inoculated samples. At the same time, the degradation time of oleuropein was shortened, leading to the production of higher levels of hydroxytyrosol. Based on this evidence, the establishment of starter culture driven Picual olives fermentation is strongly recommended. It is crucial to mention that the inoculated treatment with reducing sodium content was highly appreciated by the sensory panel, enhancing the hypothesis that the production of Picual table olives at reduced NaCl levels is achievable.

Physicochemical characterization and antioxidant activities of Chongqing virgin olive oil: effects of variety and ripening stage

This study characterized the quality, composition and antioxidant activities of olive oil from four olive varieties grown in Chongqing, southwest of China. With the fruit skin turned from green to semi black, the percentage of oleic acid decreased while the percentage of linoleic acid increased. The highest concentrations of total phenolic content, total flavonoid content and total antioxidant activity were found in the Coratina olive oils, in which the lowest content of oleuropein was also observed. Significant differences of fatty acid composition at sn-2 position were observed among the varieties, with the percentage of oleic acid at sn-2 position in Picual olive oils were significantly higher than that of other varieties (p < 0.05). In addition, the different varieties of olive oil samples were divided into three categories by principal component analysis (PCA), and the quality of Coratina olive oils were greatly affected by fruit ripening stage. With the fruit ripening, the levels of hydroxytyrosol, rutin, total phenolics, total flavonoids and antioxidant activities in Coratina olive oil all declined. This work can provide guidance for the harvesting time and processing of olives in Chongqing.

Productivity and Fruit Quality of Manzanello and Picual Olive (Olea europaea L.) Cultivars as Influenced by Spraying Lithovit under Different Irrigation Levels

Olive tree is the favorable choice to cultivate in desert lands due to high stress tolerance of its tree. Although olive tree tolerates the low availability of water in the soil by means of morphological, physiological and biochemical adaptations, the Productivity and fruit quality of it decrease gradually with increasing water stress. So we have initiated this study to follow up the effect of spraying Lithovit (Ca CO3 &amp; Mg CO3) on the productivity and fruit quality of Picual and Manzanello olives which exposure to different irrigation levels. Four concentrations of Lithovit were sprayed on olive (Olea europaea var. Manzanello) trees (0, 2, 4 and 6 g/L) under three irrigation levels (50, 75 and 100% of evapotranspiration for crop “ETc”) during 2017, 2018 seasons.&#x0D; Spraying Lithovit at 6 g/L recorded the highest values of all fruit physical characteristics of both cultivars in the two seasons. Furthermore, 2 g/L had the highest values of retained fruit percentage of both cultivars which led to increase the yield in the first and second seasons. Concerning irrigation levels, the values of fruit physical characteristics of both cultivars were the lowest values with applying 50% of ETc irrigation level. These values increased with decreasing water stress in the first and second seasons. Concerning retained fruit percentage and yield of Picual and Manzanello, the most promising level of irrigation was 75% of ETc level because it recorded the highest values of yield. Moreover 100% of ETc enhanced the fruit quality.

Variations in fatty acid composition and antioxidant content in olive fruits as a result of the application of phytoregulators to the olive tree (Olea europaea L.)

ABSTRACT A new procedure to minimize the degradation of fatty acids and polyphenols during the olive storage is here proposed. This procedure is based on pre-harvest treatments of Arbequina and Picual olive trees with methyl jasmonate and abscisic acid. As a result, total phenolic content increased in all treated Arbequina olives as compared with controls. In contrast to Arbequina, only abscisic acid resulted in total phenolic content increase in Picual olives. Regarding the antioxidant activity, neither of the phytoregulators was effective. Fatty acid composition was also affected by both of them in Arbequina and Picual. Saturated fatty acid decreased with both methyl jasmonate and abscisic acid whereas unsaturated fatty acids increased significantly in treated olives. Olives with higher antioxidant activity exhibited higher unsaturated/saturated fat ratio. The application of phytoregulators to olive tree can be interesting to the oil industry particularly when a delay in oil processing occurs and olives have to be stored.

Water Stress, Irrigation and Concentrations of Pentacyclic Triterpenes and Phenols in Olea europaea L. cv. Picual Olive Trees.

Pentacyclic triterpenes and phenols are two types of bioactive molecules found in olive trees that have important activities related to health and disease prevention. Triterpenes, including oleanolic acid, maslinic acid, erythrodiol and uvaol, show antitumoral activities, and phenols such as oleuropein, tyrosol, and hydroxytyrosol are natural antioxidants. The concentration of these metabolites is considered a marker of the quality of olives and olive oil. In recent years, a lack of rain water has caused important economic losses relating to olive trees grown in Jaén, Spain. In this work, we investigated the effect of water stress by drought on the concentration of pentacyclic triterpenes and phenols in the fruits, leaves, stems and roots of cv. Picual olive trees, by comparing the concentration found in water-stressed versus irrigated plants. We used HPLC-UV/Vis and HPLC-MS to identify and determine the concentration of each individual compound. Our results showed that important changes in the concentration of these compounds are produced in response to water stress in different organs. The total content of most of these compounds in the fruits was significantly reduced, affecting their quality and production.

EFFECT OF FOLIAR APPLICATION WITH ALGAE AND MORINGA LEAVES EXTRACTS ON VEGETATIVE GROWTH, LEAF MINERAL CONTENTS, YIELD AND CHEMICAL FRUIT QUALITY OF PICUAL OLIVE TREES

This study was carried out during 2017 and 2018 seasons on adult Picual olive cv. (8 years old) in a private orchard located at Cairo Ismailia Desert Road, (about 80 Km from Cairo), Ismailia Governorate, Egypt. Trees are grown in sandy soil, under drip irrigation system, uniform in shape and received the common horticultural practices, therefore, this work aims to study the effect of spraying different concentrations and dates spray of algae and moringa leaf extract (MLE) for tow times on the vegetative growth, leaf mineral contents, yield and fruit chemical properties of Picual olive trees. Results indicated that all different spraying treatments of algae and moringa extract at different spraying dates had a positive effect on vegetative growth, leaf mineral contents, fruit set, yield and fruit chemical properties in comparison with the control. Treatments of algae extract at 0.4% + moringa leaves extract at 2% and algae extract at 0.4% + moringa leaves extract at 4% were the most effective treatments to increase vegetative growth, improve leaf mineral content, fruit set, yield and oil content. Thus, these treatments can be recommended for commercial use under similar conditions

Abscisic Acid Sprayed on Olive Tree (Olea europaea L.) Affects the Phenolic Composition of Olive Fruit Cultivars

The aim of this research was to study the effect of abscisic acid pre-harvest treatment on the phenolic composition of olive fruits. To that end we applied abscisic acid (i.e., 50 mg/L and 100 mg/L) on Arbequina and Picual olive trees. Two different days of harvesting (i.e., day 3 and 6 after treatment) were also included in the study. Although the results obtained depended on the cultivar and on the day of harvesting a general trend was established. The treatment with 50 mg/L of abscisic acid resulted in higher total phenol content but significant decrease in the DPPH activity. In contrast, olives treated with 100 mg/L abscisic acid resulted in higher total phenol content, DPPH activity and contents of oleuropein, hydroxytyrosol and phenolic acids as compared with controls. The best values of total phenol content and IC50 were obtained for treated Picual olives (727.75 mg gallic kg-1 and 889.72 µg/ml, respectively) whereas the highest values of oleuropein and hydroxytyrosol were measured for treated Arbequina olives (508.94 and 559.67 mg kg-1, respectively). Phenolic acid content was also higher in Picual olives treated with 100 mg/L of abscisic acid. Particulary, values ranged from 7.26 mg kg-1 for caffeic acid to 92.38 mg kg-1 for chlorogenic acid. Exogenous abscisic acid applied to olive trees is a promising agronomic practice to obtain olives enriched in antioxidants.

Effect of the Treatment of the Olive Tree (&lt;i&gt;Olea europaea &lt;/i&gt;L.) on the Phenolic Content and Antioxidant Properties in Olive Fruits

We here investigate the effects of the application of methyl jasmonate to olive trees on antioxidant composition of olive fruits. Two cultivars (ie, Arbequina and Picual) were evaluated in our study. As a result, the total phenol content increased significantly with the treatment in Arbequina (from 155.89 to 434.22 mg gallic acid kg-1) whereas decreases were observed in Picual (from 338.27 to 127.71 mg gallic acid kg-1). Similarly, decreases in phenolic acid content were measured in Arbequina whilst no effect was observed in Picual olives. However, the contents of oleuropein and hydroxytyrosol did not increase with the pre-harvest methyl jasmonate for both Arbequina and Picual. Also for both cultivars the treatment of the olive trees increased the free radical scavenging activity of the olive fruits (IC50 from 514.36 to 1125.46 µg/mL in Arbequina and from 611.98 to 114.55 µg/mL in Picual). The results here found are deeply discussed.

EFFECT OF SOME NATURAL EXTRACTS, INDOLBUTIRIC ACID AND NAPHTHALENE ACETIC ACID ON ROOTING OF PICUAL OLIVE CUTTINGS

This study was carried out during 2014 and 2015 seasons in a private plastic green house at Belbies District, Sharkia Governorate, Egypt in an attempt to replace the traditional olive cutting rooting synthetic growth regulators by some auxin releasing natural extracts. Cuttings of Picual olive cv. were prepared on November of each season (about 15 cm long and7-9 mm in diameter), cutting were dipped in concentrations of indole-3-Butyric acid (IBA) at 4000 ppm and naphthalene acetic acid (NAA) at 500 ppm solution for 5 seconds or soaked in the natural extracts for half hour. The results revealed that the maximum rooting percentage (81.44 and 85.60%), number of roots/cutting (14.84 and 14.90 root/cutting), shoot number/ transplant (2.74 and 2.17 shoot/plant), leaf number/plant (6.49 and 6.61 leaf/plant) and bud sprouting percentage (48.46 and 48.14 %) respectively were recorded for cuttings dipped in IBA at 4000 ppm in comparison with those dipped in moringa extracts, which gained the lowest values of the considered parameters during the two seasons. The highest cutting survival percentages were recorded for IBA and NAA treatments, garlic at 10 or 20%, liquorice at10 g and algae at 2.5 or 5 cm in both seasons without significant differences between them. Total carbohydrates percentages in the roots and shoots were gradually increased with the advance in planting months, and reached the highest values after seven months, but total soluble phenols in the roots were decreased after six months then increased in the seventh month in both seasons. The algae, garlic and liquorice treatments were considered the best natural extracts compared to yeast and in turn can be used as an alternative of growth regulators for rooting Picual olive cuttings.

HPLC-UV Polyphenolic Profiles in the Classification of Olive Oils and Other Vegetable Oils via Principal Component Analysis

High performance liquid chromatography-ultraviolet (HPLC-UV) was applied to the analysis and characterization of olive oils and other vegetable oils. A chromatographic separation on a Zorbax Eclipse XDB-C8 reversed-phase column was proposed under gradient elution, employing 0.1% formic acid aqueous solution and methanol as mobile phase, for the determination of 14 polyphenols and phenolic acids, allowing us to obtain compositional profiles in less than 20 min. Acceptable sensitivity (limit of detection (LOD) values down to 80 µg/L in the best of cases), linearity (r2 higher than 0.986), good run-to-run and day-to-day precisions (relative standard deviation (RSD) values lower than 11.5%), and method trueness (relative errors lower than 6.8%) were obtained. The proposed HPLC-UV method was then applied to the analysis of 72 oil samples (47 olive oils and 27 vegetable oils including sunflower, soy, corn, and mixtures of them). Analytes were recovered using a liquid–liquid extraction method employing ethanol:water 70:30 (v/v) solution and hexane as extracting and defatting solvents, respectively. HPLC-UV polyphenolic profiles using peak areas were then analysed by principal component analysis (PCA) to extract information from the most significant data contributing to the characterization and classification of olive oils against other vegetable oils, as well as among Arbequina and Picual olive oil varieties. PCA results showed a noticeable difference between olive oils and the other classes. In addition, a reasonable discrimination of olive oils as a function of fruit varieties was also encountered.

Carcinogénesis experimental con 7,12-dimetilbenzantraceno (DMBA) y su inhibición con aceite de oliva virgen extra y dieta con aceitunas maduras (variedad Picual)

DMBA is a carcinogen that induces carcinomas within a few weeks of application. Forty-four male hamsters were divided into four groups: DMBA dissolved in paraffin oil (DMBA-Po), DMBA dissolved in olive oil (DMBA-Oo), paraffin oil and olive oil. Their mouths were swabbed daily with paraffin oil or extra virgin olive oil alternatively for the first two weeks, during the biweekly application of DMBA at 0.5% diluted in paraffin oil or olive oil for five weeks and daily until the twentieth week. The animals in the DMBA-Oo and olive oil groups received an additional diet of mature Picual olives. The DMBA-Po carcinogen effect (35 carcinomas) is 100% and the inhibitory effect 0. The combination of olive oil as DMBA solvent and the ad libitum diet with Picual olive has an inhibitory effect of 80%, with only three intraepithelial carcinomas and four verrucous carcinomas occurring and no invasive carcinomas.

Characterization of resistance against the olive‐defoliating Verticillium dahliae pathotype in selected clones of wild olive

Verticillium wilt of olive is best managed by resistant cultivars, but those currently available show incomplete resistance to the defoliating (D) Verticillium dahliae pathotype. Moreover, these cultivars do not satisfy consumers' demand for high yields and oil quality. Highly resistant rootstocks would be of paramount importance for production of agronomically adapted and commercially desirable olive cultivars in D V. dahliae‐infested soils. In this work, resistance to D V. dahliae in wild olive clones Ac‐13, Ac‐18, OutVert and StopVert was assessed by quantifying the fungal DNA along the stem using a highly sensitive real‐time quantitative polymerase chain reaction (qPCR) protocol and a stem colonization index (SCI) based on isolation of V. dahliae following artificial inoculations under conditions highly conducive for verticillium wilt. Ac‐13, Ac‐18, OutVert and StopVert showed a symptomless reaction to D V. dahliae. The mean amount of D V. dahliaeDNA quantified in stems of the four clones ranged from 3.64 to 28.89 pg/100 ng olive DNA, which was 249 to 1537 times lower than that in susceptible Picual olive. The reduction in the quantitative stem colonization of wild olive clones by D V. dahliae was also indicated by a sharp decrease in the SCI. Overall, there was a pattern of decreasing SCI in acropetal progression along the plant axis, as well as correlation between positive reisolation and quantification of pathogen DNA. The results of this research show that wild olive clones Ac‐13, Ac‐18, OutVert and StopVert have a valuable potential as rootstocks for the management of verticillium wilt in olive.