Nutritional composition, lipid profile and stability, antioxidant activities and sensory evaluation of pasta enriched by linseed flour and linseed oil.

Pasta assortments fortified with high quality foods are a modern nutritional trends. This study, explored the effects of fortification with linseed flour (LF) and linseed oil (LO) on durum wheat pasta characteristics. Wheat flour semolina was replaced with 5%, 10% and 15% of LF or 1%, 2.5% and 5% of LO. Control pasta CP (without LF or LO addition), LF-enriched pasta LFP 5%, LFP 10% and LFP 15% and LO-enriched pasta LOP 1%, LOP 2.5% and LOP 5% was compared for the proteins, fat and phenolic contents and fatty acids (FA) profile. Impact on lipid oxidation and sensory evaluation were also determined. Fortification of pasta with LF improved significantly (p < 0.05) the contents of protein, fat and phenolic compared to CP whereas the enrichment of pasta with LO resulted in a significant increase (p < 0.05) in the content of fat and a significant decrease in protein and phenolic contents. All the formulations decreased the saturated FA percent and increased the polyunsaturated FA percent with enhancement of omega-3 FA content. Antioxidant activity measured by FRAP and DPPH assays was improved after the fortification. For lipid oxidation, the replacement of semolina by LF or LO promoted an increase (p < 0.05) on TBARS values in level-dependent manner. Regarding sensory evaluation, the two types of fortification did not affect the taste; flavor and aroma of cooked pasta, but LOP 5% showed the highest score of the overall acceptability. The results recommended the possibility of producing pasta supplemented with LF or LO (even at a level of 15% and 5% respectively) as a functional food.

Drought stress improved the capacity of Rhizophagus irregularis for inducing the accumulation of oleuropein and mannitol in olive (Olea europaea) roots.

Olive trees are often subjected to a prolonged dry season with low water availability, which induces oxidative stress. Arbuscular mycorrhizal (AM) symbioses can improve olive plant tolerance to water deficit. This study investigated several aspects related to drought tolerance in AM fungi olive plants. Non-AM and AM plants were grown under well-watered or drought-stressed conditions, and mycorrhizal growth response, neutral lipid fatty acid (NLFA)16:1ω5 and phospholipid fatty acid (PLFA) 16:1ω5 in roots (intraradical mycelium) and in soil (extraradical mycelium), carbohydrates (monosaccharides, disaccharides and polyols) and phenolic compounds (phenolic alcohols, flavonoids, lignans, secoiridoids and hydroxycinnamic acid derivatives) were determined. Results showed that the amounts of PLFA 16:1ω5 and NLFA 16:1ω5 were significantly influenced by drought stress conditions. The NLFA 16:1ω5/PLFA 16:1ω5 ratio showed a dramatic decrease (-62%) with the application of water deficit stress, indicating that AM fungi allocated low carbon to storage structures under stress conditions. Mannitol and verbascoside are the main compounds detected in the roots of well-watered plants, whereas oleuropein and mannitol are the main compounds differentially accumulated in the roots of water-stressed plants. The oleuropein/verbascoside ratio increased in the case of drought-stressed AM plants by 30%, while the mannitol/oleuropein ratio was decreased by 46%, when compared to the non-AM stressed plants. Mycorrhization therefore oriented the flux toward the biosynthetic pathway of oleuropein and the data suggest that sugar and phenolic compound metabolism may have been redirected to the formation of oleuropein in roots of AM stressed plants, that may underlie their enhanced tolerance to drought stress.

Root verbascoside and oleuropein are potential indicators of drought resistance in olive trees (Olea europaea L.).

Polyphenols are constituents of all higher plants. However, their biosynthesis is often induced when plants are exposed to abiotic stresses, such as drought. The aim of the present work was to determine the phenolic status in the roots of olive trees grown under water deficit conditions. The results revealed that roots of water-stressed plants had a higher content of total phenols. The main compound detected in well-watered olive tree roots was verbascoside. Oleuropein was established as the predominant phenolic compound of water-stressed plants. The oleuropein/verbascoside ratio varied between 0.31 and 6.02 in well-watered and water-stressed plants respectively, which could be a useful indicator of drought tolerance in olive trees. Furthermore, this study is the first to provide experimental evidence showing that luteolin-7-rutinoside, luteolin-7-glucoside and apigenin-7-glucoside were the dominant flavonoid glucosides in olive tree roots and showed the most significant variations under water stress.

Long-term field evaluation of the changes in fruit and olive oil chemical compositions after agronomic application of olive mill wastewater with rock phosphate.

The objectives of this study were to determine the long-term effects of agronomic application of olive mill wastewater (OMW) with rock phosphate (RP) in a field of olive trees, on olive fruits and oil quality. The results revealed that olive fruits of OMW-RP amended plants had higher contents of polyphenols and mannitol indicating that agronomic application of OMW with RP generated an oxidative stress. Land spreading of OMW with RP altered the relative proportions of individual sugars in leaves and fruits. Consequently, the oil content decreased significantly, and a marked decrease in the contents of carotenoids and chlorophylls was also observed. Changes also took place in the composition of fatty acids, particularly by the increase of linoleic acid and the decrease of oleic acid. Our results suggested that the use of OMW in combination with RP is expected to have a major negative impact on olive fruit and oil quality.

Modification of pomological characteristics and flavour components of fruits and virgin olive oil following wastewater irrigation and soil tillage.

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.

Oil Characterization and Lipids Class Composition of Pomegranate Seeds.

This study aims to investigate the physicochemical characteristics, phenolics content, and oil composition of pomegranate oil seeds (PSO). Quality indices, pigments, phenolics content, and antioxidant activity were determined. PSO was fractioned into polar lipids: glycolipids (GL) and phospholipids (PL). Sterols profile and fatty acids composition of total lipids (TL), GL, and PL were determined by GC/FID. The free acidity, the peroxide value, and the specific extinction coefficients were, respectively, 1.69%, 3.42 in milliequivalents of active oxygen per kilogram of oil, 4.15, and 3.95. PSO is rich in phenols (93.42 mg/Kg) but poor in pigments. The sterols markers were ß-sitosterol (77.94%), Δ5-avenasterol (7.45%), and campesterol (6.35%). Oil content was 12.2%, wherein 23.9% were GL and 24.35% were PL. TL were rich in unsaturated fatty acids (63.17%), while saturated fatty acids were more present in PL and GL (71.97% and 66.29%, resp.). Conjugated fatty acids were about 13.30%, 2.03%, and 4.91%, respectively, in TL, PL, and GL. The cis/trans ratio of TL, PL, and GL was, respectively, 49.82%, 42.91%, and 27.39%. Monounsaturated fatty acids were more bound in PL, whereas polyunsaturated fatty acids were more bound in GL. PSO is a good source of essential fatty acids, phenolics compounds, phytosterols, and lipid-soluble fractions.

Characterization of fig achenes' oil of Ficus carica grown in Tunisia.

This work investigated the composition of the oil extract from achenes of "Kholi" variety of Ficus carica, grown in Tunisia. Fatty acid and sterol compositions were analyzed by gas chromatography (GC) coupled to flame ionization detector (FID). Furthermore, the antioxidant capacity in fig achenes' oil was assessed by employing two different in vitro assays such as DPPH, ABTS(+) radical scavenging capacities. Our results indicated that the fig achenes' oil is a rich source of bioactive molecules. The soxhlet n-hexane extraction of these achenes produced a total oil yield of 16.24%. The predominant fatty acid was linolenic acid. Concerning phytosterols, the total amount reached 1061.45 mg/100 g with a predominance of Δ(5,23)-stigmastadienol (73.78%). Regarding antioxidant activities, the half maximal inhibitory concentration (IC50) was 215.86 µg/ml and Trolox equivalent antioxidant capacity (TEAC) was 95.25 mM. These data indicate that fig achenes oil of F. carica could be potentially useful in food and pharmaceutical applications.

Accumulation of flavonoids and phenolic compounds in olive tree roots in response to mycorrhizal colonization: A possible mechanism for regulation of defense molecules.

The arbuscular mycorrhizal (AM) fungus promotes plant growth and can alter the production of primary and secondary metabolites. The aim of this work was to determine the influence of AM fungi colonization on the content of phenolic compounds, flavonoids and soluble carbohydrates in olive (Olea europaea L.) tree roots. The results revealed that mycorrhizal plants had a higher content of flavonoids and total phenols. Analysis of sugar contents showed enhanced levels of sucrose and fructose in mycorrhizal roots, while glucose amounts stayed constant. The DPPH radical-scavenging activity of the mycorrhizal root methanolic extracts was higher than that of the non- mycorrhizal root methanolic extracts. These results indicated that olive tree roots contain significant amounts of phenolic compounds, important factors for antioxidant capacity, which can be substantially modified by colonization of olive trees with AM fungi.

Determination of mannitol sorbitol and myo-inositol in olive tree roots and rhizospheric soil by gas chromatography and effect of severe drought conditions on their profiles.

This study reports a method for the analysis of mannitol, sorbitol and myo-inositol in olive tree roots and rhizospheric soil with gas chromatography. The analytical method consists of extraction with a mixture of dichloromethane:methanol (2:1, v/v) for soil samples and a mixture of ethanol:water (80:20) for root samples, silylation using pyridine, hexamethyldisilazane (HMDS) and trimethylchlorosilane (TMCS). The recovery of mannitol sorbitol and myo-inositol (for extraction and analysis in dichloromethane:methanol and ethanol:water) was acceptable and ranged from 100.3 to 114.7%. The time of analysis was <24 min. Among identified polyols extracted from rhizosphere and roots of olive plants, mannitol was the major compound. A marked increase in mannitol content occurred in rhizosphere and roots of water-stressed plants, suggesting a much broader role of mannitol in stress response based on its ability to act as a compatible solute.

Nutritional quality of fresh and heated Aleppo pine (Pinus halepensis Mill.) seed oil: trans-fatty acid isomers profiles and antioxidant properties.

Numerous studies have focused on trans fatty acids (TFA) technologically produced by partial hydrogenation of oils. However, TFA can also be present in fresh oils. For this reason, cis fatty acid (CFA), TFA and conjugated linoleic acid (CLA) of fresh and heated Aleppo pine seed oil (APSO) at frying temperature (180 °C) were evaluated and correlated with the antioxidant characteristics. Results showed that fresh APSO had a low oleic/linoleic ratio O/L (0.4). Total TFA in fresh APSO reached 1%. The predominant TFA was 18:2 n-6 (t9, t12) in both fresh and heated APSO. Individual TFA increased with significant differences (p < 0.05) with heating time. CLA occurred after 4 h and significantly increased (p < 0.05) accounting 10% of total TFA after 10 h. Total TFA are negatively correlated with α-tocopherol, γ-tocopherol (p < 0.05) and carotenoïds (p < 0.01) and positively correlated with remaining DPPH. Oil stability index (OSI) showed significant negative correlation with TFA (r = -0.925; p = 0.008). A principal component analysis (PCA) showed a clear discrimination between fresh and heated oils. Temperature, heating time, unsaturation degree and antioxidants are combined factors which significantly affect the isomerization rate and nutritional quality of APSO.

Colonization of olive trees (Olea europaea L.) with the arbuscular mycorrhizal fungus Glomus sp. modified the glycolipids biosynthesis and resulted in accumulation of unsaturated fatty acids.

The influence of arbuscular mycorrhizal (AM) fungi colonization on photosynthesis, mineral nutrition, the amount of phospholipids and glycolipids in the leaves of olive (Olea europaea L.) trees was investigated. After six months of growth, the rate of photosynthesis, carboxylation efficiency, transpiration and stomatal conductance in mycorrhizal (M) plants was significantly higher than that of non-mycorrhizal (NM) plants. The inoculation treatment increased the foliar P and Mg but not N. The amount of glycolipids in the leaves of M plants was significantly higher than that of NM plants. However, the amount of phospholipids in the leaves of M plants was not significantly different to that in the leaves of NM plants. Also, we observed a significant increase in the level of α-linolenic acid (C18:3ω3) in glycolipids of M plants. This work supports the view that increased glycolipids level in the leaves of M plants could be involved, at least in part, in the beneficial effects of mycorrhizal colonization on photosynthesis performance of olive trees. To our knowledge, this is the first report on the effect of AM fungi on the amount of glycolipids in the leaves of mycorrhizal plants.

Effect of nutrient-based fertilisers of olive trees on olive oil quality.

BACKGROUND: This work was conducted to determine the effects of two nutrient-based fertilisers on the general physicochemical characteristics (including free fatty acid content, peroxide value and UV spectrophotometric characteristics), fatty acid profile, total phenols, o-diphenols and phytosterol composition of olive oil. Foliar applications were carried out in two successive years and included four treatments: TC (control, without foliar nutrition), T1 (rich in nitrogen, applied at the start of vegetation, 10 days later and 20 days later), T2 (rich in boron, magnesium, sulfur and manganese, applied at the beginning of flowering and 10 days later) and T3 (T1+T2). At the end of the experiment (after 2 years), oils were extracted and analysed. RESULTS: No effect was found on either general physicochemical characteristics or fatty acid composition. Foliar fertilisation caused a significant decrease in both polyphenol and o-diphenol contents. Total sterol content was unaffected by foliar fertilisation. However, the phytosterol composition of the oil, particularly its ß-sitosterol level, was markedly improved after foliar nutrient application. Principal component analysis of the phytosterol composition showed discrimination between the control oil and the oils from T1, T2 and T3 treatments. CONCLUSION: The results of this study extend the current knowledge of such cross-talk between plant nutrition and quality of oil.

Fatty acid profiles, antioxidant compounds and antiradical properties of Pinus halepensis Mill. cones and seeds.

BACKGROUND: Pinus halepensis (Aleppo pine) is a widespread tree that can be found in both natural and urban environments. A discrimination study based on the antioxidant compounds, antioxidant capacity and fatty acid (FA) profile of P. halepensis cones (PHC) and seeds (PHS) was performed. RESULTS: The total amount of phenols was about 72-fold higher in PHC extract than in PHS extract (P < 0.001). Anthocyanin and carotenoid contents were 10- and 12-fold higher respectively in PHC extract. PHC and PHS extracts at a concentration of 1 mg mL(-1) differed significantly in free radical-scavenging activity on 2,2-diphenyl-1-picrylhydrazyl radical (DPPH(•)) (86.65 vs 16.97%). PHC had higher antioxidant ability on 2,2'-azino-bis(3-ethylbenzothialozine-6-sulfonic acid) radical cation (ABTS(•+)) than PHS (EC(50) 0.368 vs 2.345 mg mL(-1)). The FA profile of PHC oil revealed its richness in saturated FAs (41.5%) and high levels of trans FA isomers, with a predominance of trans,trans-linoleic acid (4.74%). However, polyunsaturated FAs in PHS oil represented more than 64% of total FAs. CONCLUSION: PHC showed important antioxidant activities as well as high levels of bioactive compounds. Thus PHC is a potential source of natural antioxidants that may afford several health benefits. However, the lipid extract of PHS seems to have more nutritional value as a polyunsaturated oil than that of PHC, which is high in saturated and trans FAs.

trans-Fatty acid isomers in two sesame (Sesamum indicum L.) seed byproducts under processing.

The present study has been inspired by the growing need for rigorously controlling the nutritional quality and safety of food products. The impact of application in the food industry on fatty acids composition, trans-fatty acids (TFAs), and conjugated linoleic acid (CLA) profiles were investigated in a highly consumed candy byproduct of sesame seed (chamia) in comparison to fresh sesame seed oil (SSO) and heated SSO under simulated frying experiments. The effect of treatment on SSO was studied by determining the TFA and CLA changes. Results showed significant differences between the two byproducts in TFA and CLA amounts. Total TFAs were found to be significantly higher in chamia than fresh SSO (1.31 versus 0.066%, respectively; p < 0.05) and even higher than all heated SSO from 2 to 10 h at 180 °C (1.31 versus 0.33%, respectively; p < 0.05). A significant linear relationship was found between trans-monounsaturated fatty acid (MUFA), trans-polyunsaturated fatty acid (PUFA), and total TFA and the time of processing, with a correlation coefficient (R(2)) greater than 0.9 for TFA and PUFA, with a higher correlation assigned to PUFA (r = 0.988; p < 0.001), followed by TFA (r = 0.959; p < 0.01) and MUFA (r = 0.844; p < 0.05). Principal component analysis of the fatty acid (FA) profiles showed discrimination between chamia and both fresh and heated SSO. A high stability of SSO against isomerization reactions as compared to their chamia sample counterpart has been noted. These findings suggest that the food industry engenders relatively higher changes in fatty acid configurations than the frying process.

Effect of controlled crossing on the triglyceride and fatty acid composition of virgin olive oils.

Our study reports the triglyceride (triacylglycerol, TAG) composition of five new Tunisian virgin olive oil cultivars obtained through controlled crossings of the cultivar (cv.) Chemlali Sfax. These cultivars have been selected among a progeny of 500 olive descendants, based on an evaluation of the fatty-acid (FA) composition of their oils. Among these samples, two were derived from the crossing with the cv. Sigoise as pollinator (SM634) or pollen acceptor (SM1110) and the others from the crossing with the cv. Meski as pollen acceptor (SM513, SM514, and SM517). The five descendants were characterized by a good fat value, a balanced FA composition, and a high content of triolein, varying between 26.9 (SM514) and 45.46% (SM1110). They had an improved FA composition as compared to that of the cv. Chemlali Sfax and their fruits were slightly bigger. The principal component analysis suggested that the TAG variables were more suitable than the total FAs for an optimum classification of the cultivar samples analyzed. The cultivars obtained through the crossing with the cv. Sigoise (as pollen acceptor or pollinator) had a more favorable composition of FAs and TAG than those obtained through the crossing with the cv. Meski, which indicated that genetic factors had the most important influence on the quality of the virgin olive oils.

Agronomic application of olive mill wastewaters with phosphate rock in a semi-arid Mediterranean soil modifies the soil properties and decreases the extractable soil phosphorus.

Olive mill wastewater (OMW), a by-product of the olive-mill industry, is produced in large amounts in Mediterranean countries. The presence of indigenous phosphate deposits in some countries like Tunisia provides an incentive for direct application or local chemical treatment at low cost to improve the solubility of low reactive phosphate rocks (PRs). The use of naturally occurring low-molecular weight organic acids (LMWOAs) that are present in OMW represents a new perspective in PR research and a possible solution for the recycling of the OMW. The present work was aimed at evaluating, under natural situations (field of olive trees), the effects of agronomic application of OMW (amounts applied: 30, 60 m(3) ha(-1)) with PR (amounts applied: 150 kg ha(-1)) on olive trees soil properties. We measured organic C, nitrogen (N), extractable phosphorus (P), exchangeable calcium (Ca), and exchangeable potassium (K), as well as other properties (pH and electrical conductivity). Our data provide evidence that agronomic application of OMW with PR has important effects on soil properties. Increases in organic C, total N, extractable P and exchangeable potassium (K) were found after the first agronomic application of OMW and PR. These increases were only temporary, following the second agronomic application of OMW and PR, significant reductions were detected in the extractable soil P (19.67 mg kg(-1) in the control soil vs. 8.99 mg kg(-1) in the amended soil). Changes in the extractable soil P could alter plant productivity and plant community structure because shifts in nutriment availability can affect the balance between limiting and non-limiting nutrients.