Oleaster (var. sylvestris) and subsp. cuspidata are suitable genetic resources for improvement of the olive (Olea europaea subsp. europaea var. europaea)

The olive belongs to Olea, a complex genus and to a species with six subspecies. Subsp. europaea includes both the cultivated olive and the oleaster, the wild ancestor of the olive. Little is known on the phenotype of fruits from subsp. cuspidata. We aimed to compare europaea and cuspidata trees for oil content and composition and to verify whether natural hybrids may exist between the two subspecies. Specimens were from Kenya and putative natural hybrids between cuspidata and europaea were from Stellenbosch (South Africa). Cultivar and oleaster trees were sampled in France (continental and Corsica), Italy (Continental and Sardinia) and Tunisia. We have examined the fruit (drupe) structure between subsp. cuspidata and europaea and extracted oil from the pulp, seed and total drupe. Comparison for oil content was made between the cultivated olive and the oleaster and some cuspidata trees from Kenya. A few of cuspidata individuals from Botanical gardens do not enable phenotyping for oil content and composition. Oil composition analyses were performed for the main fatty acids to compare the three taxa. We used microsatellite markers at 11 loci to compute genetic distances between cuspidata, oleaster and cultivar trees and to reveal eventual hybrids. The SSR polymorphisms were huge between the two subspecies and they revealed that putative hybrids were true hybrids sampled around olive orchards. The whole comparison of oil content shows that olive cultivars display higher oil content than the subsp. cuspidata and that the oleaster trees are intermediate, whereas for oil composition of the drupe, cuspidata from Kenya shows less oleic acid than europaea. However, the cuspidata trees show seed oil composition similarities with the other two taxa. The discussion deals with possible reasons to explain the differences and of the possible uses of these taxa for breeding both the olive and brown olive. H. Hannachi and H. Sommerlatte have equal contribution in the article.     

Comparison of the effect of fish oil and corn oil on chemical-induced hepatic enzyme-altered foci in rats

The effects of fish oil and corn oil diets on diethylnitrosamine initiation/phenobarbital promotion of hepatic enzyme-altered foci in female Sprague-Dawley rats were investigated. Groups of 12 rats were initiated with diethylnitrosamine (15 mg/kg) at 24 h of age. After weaning, they received diets containing either 13.5% fish oil plus 1. 5% corn oil or 15% corn oil for 24 weeks. Rats fed fish oil had significantly greater liver weight, relative liver weight, spleen weight, and relative spleen weight than rats fed corn oil (p < 0.05). Hepatic phospholipid fatty-acid profile was significantly affected by the type of dietary lipid. The rats fed fish oil had significantly greater hepatic phospholipid 20:5 and 22:6 than rats fed corn oil; in contrast, the rats fed corn oil had significantly greater hepatic phospholipid 18:2 and 20:4 than rats fed fish oil (p < 0.05). Rats fed fish oil had significantly lower hepatic vitamin E and PGE(2) content but significantly greater hepatic lipid peroxidation than rats fed corn oil (p < 0.05). The hepatic levels of antioxidant enzymes (GSH reductase and GST) were significantly greater in rats fed fish oil than in rats fed corn oil (p < 0.05). Except for PGST-positive foci (foci area/tissue area), all the other foci parameters (GGT-positive foci area/tissue area, GGT-positive foci no./cm(2), GGT-positive foci no./cm(3), PGST-positive foci no. /cm(2), and PGST-positive foci no./cm(3)) measured in the fish oil group were 10-30% of those in the corn oil group (p < 0.05). Analyses of Pearson correlation coefficient revealed a positive correlation between hepatic GGT- or PGST-positive foci number (no. /cm(2)) and PGE(2) content (r = 0.66, P = 0.01; r = 0.56, P = 0.02, respectively) but a negative correlation between GGT- and PGST-positive foci (no./cm(2)) and lipid peroxidation (r = -0.8, P = 0.0006; r = -0.58, P = 0.01, respectively), GSH/(GSH + GSSG) ratio (r = -0.61, P = 0.05; r = -0.4, P = 0.14, respectively), GSH reductase (r = -0.75, P = 0.002; r = -0.53, P = 0.02, respectively), and GST activities (r = -0.65, P = 0.01; r = -0.44, P = 0.07, respectively). Similar correlation between foci number (no./cm(3)) and PGE(2), lipid peroxidation, GSH/(GSH + GSSG) ratio, GSH reductase, and GST activities were obtained. The results of this study show that dietary fish oil significantly inhibited hepatic enzyme-altered foci formation compared with corn oil in rats. These results suggest that the possible mechanisms involved in this process are the stimulation of hepatic detoxification system, changes in membrane composition, inhibition of PGE(2) synthesis, the enhancement of GSH-related antioxidant capacity, and the enhancement of lipid peroxidation by fish oil.     

Effects of fly attack (Bactrocera oleae) on the phenolic profile and selected chemical parameters of olive oil

The phenolic fraction of virgin olive oil influences both its quality and oxidative stability. One of the principal threats of the quality of olive fruit is the olive fly ( Bactrocera oleae) as it alters the chemical composition. The attack of this olive pest has been studied in order to evaluate its influence on the quality of virgin olive oil (free acidity, peroxide value, fatty acid composition, water content, oxidative stability, phenols, and antioxidant power of phenolic fraction). The study was performed using several virgin olive oils obtained from olives with different degrees of fly infestation. They were acquired in different Italian industrial mills from the Abruzzo region. Qualitative and quantitative analyses of phenolic profiles were performed by capillary electrophoresis-diode array detection, and electrochemical evaluation of the antioxidant power of the phenolic fraction was also carried out. These analyses demonstrated that the degree of fly attack was positively correlated with free acidity ( r = 0.77, p < 0.05) and oxidized products ( r = 0.58, p < 0.05), and negatively related to the oxidative stability index ( r = -0.54, p < 0.05) and phenolic content ( r = -0.50, p < 0.05), mainly with secoiridoid compounds. However, it has been confirmed that the phenolic fraction of olive oil depends on several parameters and that a clear correlation does not exist between the percentages of fly attack and phenolic content.     

Infrared study of structural characteristics of Frankfurters formulated with olive oil-in-water emulsions stabilized with casein as pork backfat replacer

This article reports an infrared spectroscopic (FT-IR) study on lipids and protein structural characteristics in frankfurters as affected by an emulsified olive oil stabilizing system used as a pork backfat replacer. The oil-in-water emulsions were stabilized with sodium caseinate, without (F/SC) and with microbial transglutaminase (F/SC+MTG). Proximate composition and textural characteristics were also evaluated. Frankfurters F/SC+MTG showed the highest (P < 0.05) hardness and lowest (P < 0.05) adhesiveness. These products also showed the lowest (P < 0.05) half-bandwidth of the 2922 cm(-1) band, which could be related to the fact that the lipid chain was more orderly than that in the frankfurters formulated with animal fat and F/SC. The spectral results revealed modifications in the amide I band profile when the olive oil-in-water emulsion replaced animal fat. This fact is indicative of a greater content of aggregated intermolecular β-sheets. Structural characteristics in both proteins and lipids could be associated with the specific textural properties of frankfurters.     

Genetic differentiation in the olive complex (Olea europaea) revealed by RAPDs and RFLPs in the rRNA genes

We assessed the genetic differentiation of the Mediterranean olive from its wild relatives found in different geographic areas (Mediterranean, Asia, Africa) using eighty RAPDs revealed with eight primers. Variance analysis (AMOVA) enabled us to estimate the overall genetic differentiation parameters between wild populations. Oleasters from the Near East and Turkey were discriminated from the other Mediterranean populations. Olea laperrinei, O. maroccana and O. cerasiformis were the taxa the most related to the Mediterranean olive. In contrast, O. africana was shown to be the most genetically distant taxa from the Mediterranean olive. However, we characterised hybrid trees between these two taxa. Significant trends between genetic and geographic distances were met within the subspecies cuspidata and within the Mediterranean olive. A genetic diversity gradient was observed in both subspecies europaea and cuspidata. These results are in agreement with a mechanism of differentiation by distance in the O. europaea complex, but another non-exclusive mechanism could also be gene flow between differentiated taxa. Furthermore, we characterised the discriminating power of each RAPD to recognise the different taxa using intraclass correlation coefficients. Lastly, IGS-RFLPs enabled us to assess rDNA polymorphisms on a sub-sample of individuals. On the basis of these data, a low interspecifc differentiation was found. This suggests a recent genetic divergence between the different taxa of the O. europaea complex or the occurrence of gene flow during favourable periods or because human displacements. All the olive cultivars were genetically related to the oleaster populations supporting that Mediterranean is the olive domestication area.     

Major phenolic compounds in olive oil modulate bone loss in an ovariectomy/inflammation experimental model

This study was conducted to determine whether the daily consumption for 84 days of tyrosol and hydroxytyrosol, the main olive oil phenolic compounds, and olive oil mill wastewater (OMWW), a byproduct of olive oil production, rich in micronutrients, may improve bone loss in ovariectomized rats (an experimental model of postmenopausal osteoporosis) and in ovariectomized rats with granulomatosis inflammation (a model set up for senile osteoporosis). As expected, an induced chronic inflammation provoked further bone loss at total, metaphyseal, and diaphyseal sites in ovariectomized rats. Tyrosol and hydroxytyrosol prevented this osteopenia by increasing bone formation ( p < 0.05), probably because of their antioxidant properties. The two doses of OMWW extracts had the same protective effect on bone ( p < 0.05), whereas OMWW did not reverse established osteopenia. In conclusion, polyphenol consumption seems to be an interesting way to prevent bone loss.     

Antiatherogenic effects of structured lipid containing conjugated linoleic acid in C57BL/6J mice

Conjugated linoleic acids (CLA) were enzymatically acidolyzed with olive oil to produce structured lipids (SL), and their antiatherosclerotic properties were investigated in C57BL/6J mice. Twenty-eight mice were divided into four groups and fed control diet or atherogenic diets supplemented with high cholesterol and high fat (HCHF) containing 5% of lard, olive oil, or SL based on control diet for 4 weeks. The supplementation of SL diet (0.6% CLA) significantly reduced the levels of serum total cholesterol and total triglyceride and increased high-density lipoprotein cholesterol level as compared to lard and olive oil diet groups (p < 0.05). The activity of liver acyl CoA:cholesterol acyltransferase (ACAT) of mice fed the SL diet was significantly lower than that of mice fed the lard or olive oil diet. A reduced formation of aortic fatty streak was observed in SL group. The extent of CLA incorporation depended on tissues or types of phospholipids. More CLA was incorporated in adipose tissue (1.85 mol %) than in the liver (0.33 mol %). Besides, more CLA was found in phosphatidylethanolamine (PE) (0.47 mol %) than in phosphatidylcholine (PC) (0.05 mol %) of hepatic phospholipids. Hepatic phospholipids (PC and PE) of mice fed the SL diet contained reduced contents of arachidonic and linoleic acid compared with mice fed the olive oil or lard diet. The present study suggests that SL could be considered as a functional oil for preventing risks of atheroscelerosis.     

Changes in virgin olive oil quality during low-temperature fruit storage

'Frantoio' olive fruits were stored at low temperature (4 +/- 2 degrees C) for 3 weeks to investigate the effect of postharvest fruit storage on virgin olive oil quality. Volatile compounds and phenolic compounds explained the changes in sensory quality that could not be explained with quality indices (FFA, PV, K232, and K270). Increases in concentrations of ( E)-2-hexenal and hexanal corresponded to positive sensory quality, whereas increases in ( E)-2-hexenol and (+)-acetoxypinoresinol were associated with negative sensory quality. Volatile and phenolic compounds were also indicative of the period of low-temperature fruit storage. Oleuropein and ligstroside derivatives in olive oil decreased with respect to storage time, and their significant ( p < 0.05) change corresponded to changes in bitterness and pungency. ( Z)-2-Penten-1-ol increased during low-temperature fruit storage, whereas 2-pentylfuran decreased. Changes in volatile compounds, phenolic compounds, quality indices, and sensory notes indicated that virgin olive oil quality was lost within the first week of low-temperature fruit storage and regained at 2 weeks. This research suggests that low-temperature olive fruit storage may be beneficial, with a possibility of increasing oil yield and moderating the sensory quality of virgin olive oils. This study demonstrates that deeper insights into virgin olive oil quality changes during low-temperature fruit storage may be gained by studying volatile and phenolic compounds in addition to quality indices and physical appearance of the fruit.     

EFFECT OF FOLIAR BORON APPLICATION ON GROWTH,REPRODUCTION, AND OIL QUALITY OF OLIVE TREES CONDUCTED UNDER A HIGH DENSITY PLANTING SYSTEM

Boron (B) foliar treatments (300 mg L^?1 as Solubor DF) were applied at two different dates in 2006 and 2007, prior to flowering and just after fruit set, on olive (Olea europaea L.) trees with no visual symptoms of B deficiency. Leaf B level increased after the first application as compared to control (?B). After July treatment, leaf B levels in ?B and +B treated trees increased when compared to the first sampling date. Foliar B application did not significantly affect vegetative growth in either year. During the first year of study (considered as an “on year”), B application had no significant effect on several phenological characteristics including fruit set, yield oil contents and oil quality. In the second year (“off year”), B sprays improved blooming rate, which increased from 20% in ?B to 30% in + B treated trees, and olive yield, which increased by 27% in response to B.     

Beneficial effects of short-term nutritional counselling at the primary health-care level among Brazilian adults

OBJECTIVE: To evaluate the impact of a low-cost nutritional intervention in changing the lifestyle of adults. DESIGN: Randomised clinical trial. SETTING: Primary health-care centre in S?o José do Rio Preto, S?o Paulo State, Brazil. SUBJECTS: We randomly assigned 104 adults (83 women and 21 men aged 30-65 years, body mass index 24-35 kg m(-2), non-diabetic) into two groups: nutrition counselling and control. Each subject in the intervention group received three individualised nutritional counselling sessions during the first 6 months aimed at increasing intakes of fruits, vegetables and olive oil, reducing saturated fat and improving physical activity. Body composition, biochemical indicators and lifestyle were assessed at baseline and at 6 months and 1 year in both groups. RESULTS: After 6 months of follow-up, body weight, waist circumference, diastolic blood pressure, fasting blood glucose, total and low-density lipoprotein cholesterol, total and saturated fat, and dietary energy and cholesterol levels showed a more significant decrease among subjects in the intervention group than in the control group (P < 0.05). Moreover, the intervention group showed significantly greater improvement in each intervention goal, such as reduced intake of saturated fat and increased intakes of fruits, vegetables, fibre and olive oil (P < 0.05). After 12 months of follow-up, most of the outcomes were maintained. CONCLUSIONS: The low-cost nutritional intervention programme improved serum lipids profile and weight control, and appeared to be feasible for use at a primary health-care centre in a developing country.     

Geographical characterization of greek virgin olive oils (cv. Koroneiki) using 1H and 31P NMR fingerprinting with canonical discriminant analysis and classification binary trees

This work deals with the prediction of the geographical origin of monovarietal virgin olive oil (cv. Koroneiki) samples from three regions of southern Greece, namely, Peloponnesus, Crete, and Zakynthos, and collected in five harvesting years (2001-2006). All samples were chemically analyzed by means of 1H and 31P NMR spectroscopy and characterized according to their content in fatty acids, phenolics, diacylglycerols, total free sterols, free acidity, and iodine number. Biostatistical analysis showed that the fruiting pattern of the olive tree complicates the geographical separation of oil samples and the selection of significant chemical compounds. In this way the inclusion of the harvesting year improved the classification of samples, but increased the dimensionality of the data. Discriminant analysis showed that the geographical prediction at the level of three regions is very high (87%) and becomes (74%) when we pass to the thinner level of six sites (Chania, Sitia, and Heraklion in Crete; Lakonia and Messinia in Peloponnesus; Zakynthos). The use of classification and binary trees made possible the construction of a geographical prediction algorithm for unknown samples in a self-improvement fashion, which can be readily extended to other varieties and areas.     

Effects of different cooking procedures on lipid quality and cholesterol oxidation of farmed salmon fish (Salmo salar)

Salmon fillets were steamed, or pan-fried without oil, with olive oil, with corn oil, or with partially hydrogenated plant oil. The exchange between the salmon and the pan-frying oils was marginal, but it was detectable as slight modifications in the fatty acid pattern and the tocopherol contents according to the oil used. Primary and secondary oxidation products were only slightly increased or remained unchanged, which indicated a slight lipid oxidation effect due to the heating procedures applied. The same was observed for tocopherol levels, which remained almost stable and were not affected by the oxidation process. The sum of cholesterol oxidation products (COPs) increased after the heating processes from 0.9 microg/g in the raw sample to 6.0, 4.0, 4.4, 3.3, and 9.9 microg/g extracted fat in pan-fried without oil, with olive oil, corn oil, partially hydrogenated plant oil, and steamed, respectively. A highly significant correlation was found between the fatty acid pattern and the total amount of COPs (r2 = 0.973, p < 0.001). No change has been determined in the n-3 fatty acids content and in the polyunsaturated/saturated-ratio of the cooked salmon fillets. Moderate pan-frying (6 min total) and steaming (12 min) of salmon did not accelerate lipid oxidation but significantly increased the content of COPs. The highest increase of COPs was found through steaming, mainly due to the longer heat exposure. The used frying oils did not influence the outcome; no significant difference between heat treatment with or without oil has been determined.     

Antithrombotic lipid minor constituents from vegetable oils. Comparison between olive oils and others

Many epidemiological studies suggest that vegetable oils and especially olive oil present a protective effect against atherosclerosis. In this study, total lipids (TL) of Greek olive oils and seed oils of four kinds, namely, soybean, corn, sunflower, and sesame oil, were separated into total polar lipids (TPL) and total neutral lipids (TNL) via a novel extraction procedure. TPL and TNL of olive oil were fractionated by HPLC for further study. Each lipid fraction from HPLC separation along with TL, TPL, and TNL lipid samples from oils were tested in vitro for their capacity to induce or to inhibit washed rabbit platelet aggregation. Comparison between olive and seed oils supports the superiority of olive oil as high levels of platelet activating factor (PAF) antagonists have been detected, mainly in TPL. In addition, the structure of the most active fraction from olive oil was elucidated, as a glycerol-glycolipid. Because it has already been reported that PAF plays a pivotal role in atherogenesis, the existence of PAF agonists and antagonists in vegetable oils may explain their protective role against atherosclerosis.     

Differentiation of refined and virgin edible oils by means of the trans- and cis-phytol isomer distribution

The differentiation of nonrefined (e.g., cold-pressed) and refined edible oils is an important task in food control because of the higher commercial value of the former. Here, we explored the suitability of the relative abundance of cis-phytol as a marker for authentication of nonrefined edible oils. Phytol, the tetramethyl-branched, monoenoic alcohol, is found widespread in nature as a part of chlorophyll. In chlorophyll, only trans-phytol is found. In this study, we present a method for the analysis of the phytol isomers, considering that traces of cis-phytol (contributing 0.1% to the phytol content) can be determined next to trans-phytol. For this purpose, phytol was gathered with the unsaponifiable matter from the oil, trimethylsilylated, and analyzed by gas chromatography coupled to mass spectrometry. With this method, 27 samples of edible oils (16 refined and 11 nonrefined edible oils) were analyzed for the abundance of cis-phytol relative to trans-phytol. In the nonrefined oils (e.g., olive oil, rapeseed oil, maize oil, and sunflower oil), cis-phytol contributed 0.1% (n = 3) or less (n = 8) to the phytol content. In contrast, the refined olive oils (n = 4) contained a share of 1.3-3% cis-phytol; the refined rapeseed oil (n = 3) contained a share of 0.7-1.0% cis-phytol; and the refined sunflower oil (n = 4) contained a share of 0.3-0.9% cis-phytol. Only one refined pomegranate kernel did not contain cis-phytol. The phytol concentration was not suited to distinguish nonrefined from refined oils. In contrast, our data suggest that the virtual absence of cis-phytol can be used as a marker for nonrefined (e.g., cold-pressed) edible oils.     

Changes in volatile and phenolic compounds with malaxation time and temperature during virgin olive oil production

Virgin olive oils produced at wide ranges of malaxation temperatures (15, 30, 45, and 60 degrees C) and times (30, 60, 90, and 120 min) in a complete factorial experimental design were discriminated with stepwise linear discriminant analysis (SLDA) revealing differences with processing conditions. Virgin olive oils produced at 15 and 60 degrees C for 30 min showed the most significant (p < 0.01) differences. Discrimination was based upon volatile and phenolic compounds detected in olive oils, peroxide value (PV), free fatty acids (FFA), ultraviolet (UV) absorbances, and oil yield. There were different discriminating variables for processing conditions illustrating the dependence of virgin olive oil quality on malaxation time and temperature. Volatile compounds were the dominant discriminating variables. Common oxidation indicators of olive oil (PV, K232, and K270) were not among the variables that significantly (p < 0.01) changed with malaxation time and temperature. Variables that discriminated both malaxation time and temperature were hexanal, 3,4-dihydroxyphenyl ethyl alcohol-decarboxymethyl elenolic acid dialdehyde (3,4-DHPEA-DEDA) and FFA, whereas 1-penten-3-ol, E-2-hexenal, octane, tyrosol, and vanillic acid significantly (p < 0.01) changed with temperature only and Z-2-penten-1-ol, (+)-acetoxypinoresinol, and oil yield changed with time only. Virgin olive oil quality was significantly influenced by malaxation temperature, whereas oil yield discriminated malaxation time. This study demonstrates the two modes of hexanal formation: enzymatic and nonenzymatic during virgin olive oil extraction.     

Changes in the phenolic composition of virgin olive oil from young trees (Olea europaea L. cv. Arbequina) grown under linear irrigation strategies.

This study reports the HPLC profiles of phenolic compounds of virgin olive oils obtained from young olive trees (Olea europaea L. cv. Arbequina) and how the application of a linear irrigation strategy affected these. Hydroxytyrosol, tyrosol, vanillic acid, vanillin, 4-(acetoxyethyl)-1,2-dihydroxybenzene, p-coumaric acid, the dialdehydic form of elenolic acid linked to hydroxytyrosol and to tyrosol, lignans, and the oleuropein aglycon were found in all the oils. Hydroxytyrosol, tyrosol, vanillic acid, and p-coumaric acid contents in the oils were unaffected by linear irrigation. The concentration of lignans was lower in the oils from the least irrigated treatment and the concentration of vanillin increased as the amount of irrigation water applied to olive trees increased. However, 4-(acetoxyethyl)-1,2-dihydroxybenzene, the dialdehydic form of elenolic acid linked to hydroxytyrosol and to tyrosol, and the oleuropein aglycon, all of them hydroxyphenyl derivatives, decreased as the level of irrigation water increased. The latter three compounds represented the most considerable part of the phenolic fraction of the oils and they were shown to be correlated to the oxidative stability, the bitter index (K(225)), and the bitter, pungent, and sweet sensory attributes. Linear irrigation strategy changed the profile of the oil phenolic compounds and, therefore, changed both the organoleptic properties and the antioxidant capacity of the product.     

Comparison of natural polyphenol antioxidants from extra virgin olive oil with synthetic antioxidants in tuna lipids during thermal oxidation

Polyphenols extracted from extra virgin olive oil (EVOO) were tested for their ability to inhibit lipid oxidation of canned tuna. Hydroperoxide formation during oxidation was monitored by measurement of peroxide value and decomposition of hydroperoxides by static headspace gas chromatographic analysis of volatiles. In tuna oxidized at 40 and 100 degrees C, 400 ppm of the EVOO polyphenols was an effective antioxidant as compared with 100 ppm of a 1:1 mixture of the synthetic antioxidants butylated hydroxytoluene and butylated hydroxyanisole. However, at concentrations <100 ppm, the EVOO phenolic compounds promoted hydroperoxide formation and decomposition. The EVOO polyphenols were effective antioxidants when added to heated tuna muscle in the presence of either brine or refined olive oil. The oxidation rate in tuna muscle packed in brine was higher than that of tuna packed in refined olive oil. The EVOO polyphenols had higher antioxidant activity in the brine samples than in the refined olive oil. The higher antioxidant activity of EVOO polyphenols in tuna packed in brine may be explained by their greater affinity toward the more polar interface between water and the fish oil system.     

Virgin olive oil normalizes the altered triacylglycerol molecular species composition of adipose tissue in spontaneously hypertensive rats

The present study was conducted in order to evaluate the influence of hypertension on the triacylglycerol (TG) molecular species composition and other lipid classes of rat adipose tissue. In addition, the effect of two dietary oils, with a similar content in oleic acid but different TG moieties, was studied. Virgin olive oil (VOO) or high-oleic sunflower oil (HOSO) was added to a baseline diet (BD) and administrated to Wistar-Kyoto and spontaneously hypertensive rats (SHR) for 12 weeks. Both VOO and HOSO normalized the altered composition of TG molecular species and phospholipid (PL) fatty acids in SHR compared to animals fed BD, although the effect exhibited by VOO was greater. Rats fed HOSO showed a greater palmitic (p < 0.05) and lower linoleic acid (p < 0.05) incorporation into PL but a greater accumulation of linoleic acid-containing TG species, particularly dioleoyl-linoleoyl-glycerol, with a concomitant displacement of trilinolein. Both oils were capable of increasing the lipoprotein lipase (LPL) activity in normotensive rats, but only VOO did so in the SHR. Therefore, it was concluded that although oleic acid-rich diets improve some of the altered parameters of SHR adipose tissue, VOO is more effective than HOSO in this regard.     

Irrigation effects on quality, phenolic composition, and selected volatiles of virgin olive oils cv. Leccino

Field-grown olive trees (Olea europaea L. cv. Leccino) were used over two growing seasons to determine the effect of deficit irrigation regimes on virgin olive oil (VOO) quality. Drip irrigation was managed to maintain a predawn leaf water potential (PLWP): (a) higher than -1.1 MPa (full irrigation: FI); (b) between -1.0 and -3.3 MPa (deficit irrigation: DI); (c) higher than -4.2 MPa (severe deficit irrigation: SI). The fruit yield and oil yield of DI trees were over 90% of those of FI treatments in both years, respectively, whereas yields of SI trees ranged from 61 to 76%. The irrigation regime had minor effects on the free acidity, peroxide value, and fatty acid composition of VOO. The concentrations of phenols and o-diphenols in VOO were negatively correlated with PLWP. The concentrations of the dialdehydic form of decarboxymethyl elenolic acid linked to (3,4-dihydroxyphenyl)ethanol (3,4-DHPEA-EDA), the isomer of the oleuropein aglycon (3,4-DHPEA-EA), and the dialdehydic form of decarboxymethyl elenolic acid linked to (p-hydroxyphenyl)ethanol (p-HPEA-EDA) were lower in FI than in SI treatments. The concentrations of lignans (+)-1-acetoxipinoresinol and (+)-1-pinoresinol were unaffected by the irrigation regime. The tree water status had a marked effect on the concentration of volatile compounds, such as the C(6)-saturated and unsaturated aldehydes, alcohols, and esters.     

Correlations of the phenolic compounds and the phenolic content in some Spanish and French olive oils

The total content of phenolic compounds (TAP) in 29 different monocultivar olive oil samples from France (Aglandau and Tanche) and Spain (Cornicabra, Picual, and Verdial) was assessed by the colorimetric Folin-Ciocalteu method. Also, individual phenolic compounds were determined and quantified by liquid chromatography coupled to mass spectrometry (LC-MS). The French olive oil samples had a lower TAP compared to Spanish samples. The quantity of individual phenolics was similar except for pinoresinol, which was lower in the French olive oil samples. TAP moderately correlated to the sum of quantified compounds (r = 0.64 and p < 0.01) Partial least-squares (PLS) regression analysis emphasized the importance of hydroxytyrosol and the total amount of quantified phenolic compounds by LC-MS in the prediction of the total amount of phenolic compounds as determined by the Folin-Ciocalteu method. The amount of alpha-tocopherol was generally different among the cultivars (Tanche > Picual > Verdial > Aglandau > Cornicabra). Of all quantified phenolic compounds in French olive oil samples, only luteolin correlated well to the altitude of the olive orchards (r = 0.76, p < 0.01).