Chemical Composition of Wild Collected and Cultivated Edible Plants (Sonchus oleraceus L. and Sonchus tenerrimus L.).

The present work investigates the nutritional and bioactive composition, as well as the organoleptic and sensory properties, of S. oleraceus and S. tenerrimus, two wild plant species traditionally used in the gastronomy of the Mediterranean area. Additionally, the effect of cultivation on leaf composition was assessed to explore their potential for large-scale production and commercialization from the point of view of possible losses or gains in quality. Both species were characterized as a good source of bioactive compounds, such as vitamins, pro-vitamins and carotenoids, with health-promoting and antioxidant properties that are highly appreciated. The sensory profile revealed a good general acceptance of S. oleraceus and S. tenerrimus, indicating that they could be included in the diet. Although the cultivation of S. oleraceus resulted in a decrease in the concentration of phenolic compounds when compared to wild-harvested plants, the opposite occurred for vitamin C. In S. tenerrimus, cultivation also increased the concentration of other compounds with important nutritional and healthy properties, such as sugars, organic acids and ß-carotene. The results of the composition, organoleptic and sensory properties of S. oleraceus and S. tenerrimus support the idea of their potential to be used as edible leafy vegetables and as promising assets for functional foods.

Abatement of pesticides residues in commercial farm soils by combined ozonation-solarization treatment.

The widespread use of pesticides against agricultural pest and diseases introduces these pollutants and their transformation products into soils. The toxicity and permanence of these substances make it necessary for the development of remediation strategies in order to mitigate contamination and to further protect consumers. This work was aimed to evaluate the applicability of ozonation-solarization technology in the degradation of pesticide residues in commercial farm soils. The trial was conducted in two exploitations devoted during decades to tomato cultivation under greenhouse and net systems. Treatments were carried out using a pipping network (both superficial and sub-superficial) that delivered ozone in gaseous state after covering the soil with gas-tight plastic film to avoid ozone leaks to atmosphere. Control soil treatments, without ozone exposure, were also conducted. After 40 days of treatment, mean degradation percentages of about 55-61% for both cultivation systems were obtained, when the reduction of these pollutants in the control soils was about 8-15%. Ozonation-solarization impact was also assessed by changes on soil physical-chemical properties. Results suggest that ozonation in combination with solarization technique could be considered as a feasible approach for the remediation of pesticide-polluted farm soils.

Photocatalytic degradation of four insecticides and their main generated transformation products in soil and pepper crop irrigated with reclaimed agro-wastewater under natural sunlight.

This work is the first-ever study of the concurrence of four insecticides (chlorantraniliprole, imidacloprid, pirimicarb and thiamethoxam) and their main transformation products (TPs) in soil and pepper crop irrigated with reclaimed and non-reclaimed water under agricultural field conditions. Field experiments were conducted using different irrigation supplies: control water (CW), wastewater polluted with phytosanitary commercial products containing the studied insecticides (WW) and reclaimed wastewater after a photocatalytic processing with TiO2/Na2S2O8 at pilot plant under sunlight (RWW). Photocatalytic treatments removed most of the insecticides and their TPs generated during the photoperiod. Neither target insecticides nor their TPs were detected in pepper samples when CW and RWW were used as irrigation source, whereas the four insecticides and two TPs were detected when WW was used. In the experiment carried out with WW, all insecticides and eight TPs were detected in soil samples. The impact of using reclaimed water on the quality of pepper crop was also assessed, showing barely any significant difference.

Phenolic and Carotenoid Profile of Lamb's Lettuce and Improvement of the Bioactive Content by Preharvest Conditions.

This study characterizes the phenolic, carotenoid and chlorophyll profile of lamb's lettuce, a vegetable whose consumption in salads and ready-to-eat products is constantly growing. The MS/MS analysis allowed the identification of thirty-five phenolic compounds including hydroxybenzoic and hydroxycinnamic acids, flavanones, flavanols and flavanones, many of which are reported here in lamb's lettuce for the first time. Chlorogenic acid was the principal phenolic compound found (57.1% of the total phenolic concentration) followed by its isomer cis-5-caffeoylquinic. Other major phenolic compounds were also hydroxycinnamic acids (coumaroylquinic, dicaffeoylquinic and feruloylquinic acids) as well as the flavones luteolin-7-rutinoside, diosmetin-apiosylglucoside and diosmin. Regarding carotenoids, seven xanthophyll and four carotenes, among which ß-carotene and lutein were the major compounds, were detected from their UV-Vis absorption spectrum. In addition, chlorophylls a and b, their isomers and derivatives (pheophytin) were identified. Preharvest factors such as reduced fertilization levels or salinity increased some secondary metabolites, highlighting the importance of these factors on the final nutritional value of plant foods. Lamb's lettuce was seen to be a good potential source of bioactive compounds, and fertilization management might be considered a useful tool for increasing its nutritional interest.

Solar photocatalysis as strategy for on-site reclamation of agro-wastewater polluted with pesticide residues on farms using a modular facility.

One of the consequences of phytosanitary treatments applied to crops is the generation of a great volume of agro-wastewater having pesticide residues. These pollutants can be considered a serious threat to the environment and human health due to their capacity to affect distant areas remaining for a long time after their application. We have assessed the degradation of five pesticides in agro-waste water produced in two farms by the cleaning pesticide containers and phytosanitary treatment equipment used in the farms. For this purpose, a pilot facility was installed in both farms and advanced oxidation treatments were conducted using natural sunlight by means of Na2S2O8 and heterogeneous photocatalysis (TiO2/Na2S2O8). The remaining percentages obtained at the end of the experiments ranged from 5 to 90.1% for chlorantraniliprole, 5 to 82.3% for difenoconazole, 0.02 to 19.1% for metalaxyl, 1.4 to 74.4% for myclobutanil, and 0.3 to 61% for triadimenol. We observed a correlation between the higher remaining percentages and the total initial concentration of pollutant because of other commercial formulations applied in the farms. The results showed that this equipment could be used to eliminate or reduce the presence of pesticide residues in agro-waste water using an innovative facility installed in the farms and a renewable and economical source of energy (sunlight).

Appraisal of water matrix on the removal of fungicide residues by heterogeneous photocatalytic treatment using UV-LED lamp as light source.

In this study, the photocatalytic degradation of four fungicides, myclobutanil, penconazole and difenoconazole (triazole compounds) and boscalid (carboxamide), has been examined in different aqueous matrices (tap water, irrigation water and two WWPT effluents). Experiments were conducted at laboratory scale with different reagents-zinc oxide (ZnO), titanium dioxide (TiO2), sodium persulphate (Na2S2O8) and the combined systems ZnO/Na2S2O8 and TiO2/Na2S2O8-in water exposed to UV-LED irradiation. Previously, the effect of catalyst and oxidant loading on the disappearance kinetics of the different fungicides was assessed to know maximum degradation efficiency. The influence of water matrices and pesticide loading in removal effectiveness has been evaluated. It was observed a greater efficiency in processes conducted using the tandems ZnO/Na2S2O8 and TiO2/Na2S2O8 in irrigation and tap waters. Results showed that UV-LED are a suitable alternative for tackling the removal of organic pollutants in water.

Variation in flavonoids in a collection of peppers (Capsicum sp.) under organic and conventional cultivation: effect of the genotype, ripening stage, and growing system.

BACKGROUND: In recent years, the acreage used for organic agriculture and the demand for organic fruit and vegetables have increased considerably. Given this scenario, landraces, such as Capsicum landraces, can provide valuable germplasm. Capsicum peppers are very interesting because of their high phenolic content, and particularly their flavonoid content, which provides a high added value. Moreover, the broad genetic diversity in local varieties expands the opportunities for adaptation to organic production and for exploiting genotype × environment interactions to select peppers with the highest phenolic content. RESULTS: In this work, the main flavonoids of peppers were exhaustively evaluated over 2 years in a wide collection of heirlooms, both unripe and fully ripe, under organic and conventional cultivation. The genotype and ripening stage contributed to a high degree to the variation in flavonoids. The growing system influenced this variation to a lesser extent. Luteolin and quercetin showed the highest contributions to total phenolic content (70% and > 20%, respectively) at both ripening stages, while myricetin, apigenin, and kaempferol showed lower contributrions. The average flavonoid content was higher in ripe fruits, and organic management significantly increased the accumulation of total flavonoids and luteolin. Positive correlations between flavonoids were found at both ripening stages, especially between main flavonoids luteolin and quercetin and between kaempferol and quercetin (ρ > 0.7). CONCLUSION: Genotype × environment interaction enabled the identification of accessions with high flavonoid content grown under organic conditions at both ripening stages, particularly total flavonoids and luteolin at the fully ripe stage. Our results reinforce the importance of a wide genetic variation and of considering different ripening stages and growing conditions for breeding high-quality peppers. © 2020 Society of Chemical Industry.

Reclamation of agro-wastewater polluted with pesticide residues using sunlight activated persulfate for agricultural reuse.

The removal of 17 pesticides (pymetrozine, flonicamid, imidacloprid, acetamiprid, cymoxanil, thiachloprid, spinosad, chlorantraniliprole, triadimenol, tebuconazole, fluopyram, difenoconazole, cyflufenamid, hexythiazox, spiromesifen, folpet and acrinathrin) found in agro-wastewater from washing of containers and phytosanitary treatments equipment, has been carried out using sodium persulfate (Na2S2O8) at pilot plant scale under natural sunlight. Persulfate is a strong oxidant, inexpensive and environmentally appropriate. However, this oxidant is slow in kinetics under ordinary conditions. Na2S2O8 can be activated by ultraviolet light, generating SO4- radicals, which are also a very strong oxidizing species (E0 = 2.6 V). Previously, preliminary experiments were carried out at laboratory scale using a photoreactor to optimize the Na2S2O8 (300 mg L-1) concentration on the rate constants of the found pesticides. The residual levels of the studied pesticides in agro-wastewater (900 L) were in the range 0.02-1.17 mg L-1 for acrinathrin and fluopyram, respectively. After treatment, nearly complete degradation (>97%) of the parent molecules was achieved although 13% of initial DOC was measured. No significant differences (p < 0.05) were found when comparing grown broccoli using reclaimed and unreclaimed water.

Solar photocatalytic reclamation of agro-waste water polluted with twelve pesticides for agricultural reuse.

This study aims to demonstrate a technically feasible alternative to remove pesticide residues from agro-waste water produced in farms from remnants in containers and treatment tanks, rinse in tanks after treatments, and cleaning of machines and equipment. For this, the photocatalyzed degradation of 12 pesticides commonly used on vegetables, vines, citrus and fruit crops was investigated in aqueous suspensions of TiO2 in tandem with Na2S2O8 at pilot plant scale under natural sunlight in Murcia (SE of Spain) during summer and winter seasons. Previously, preliminary experiments were carried out at laboratory scale using a photoreactor to optimize the photocatalyst (200 mg L-1) and oxidant (250 mg L-1) concentrations on the rate constants of the studied pesticides. The photodegradation of all pesticides can be modelled assuming a pseudo-first-order kinetics. The time needed for disappearance of 90% (DT90) of the studied pesticides, was lower than 4 h in summer in all cases with the exception of cyproconazole (4.9 h), while, cyproconazole (8.9 h), metalaxil (6.1 h) and propyzamide (7.9 h) showed DT90 higher than 6 h in winter. The reaction rate was enhanced 3-fold in summer season, which is directly correlated to the higher accumulated fluence per time received during this season (about a factor of 2.9 higher than in winter). In both cases, the higher and lower degradation rates were obtained for cyprodinil and cyproconazole, respectively. The total fluence to get a 90% reduction (H90) ranged from 4.6 to 5.2 J cm-2 (cyprodinil) to 71.5-76 J cm-2 (cyproconazole).

Genotypic variability of carotenoids in traditional tomato cultivars.

Traditional varieties constitute a wide source of genetic variation that can be used per se or to obtain new cultivars with high consumer appeal and nutritional value. This work focuses on the carotenoid and chlorophyll profiles and contents of 53 traditional tomato cultivars, paying particular attention to compounds with recognized health-promoting properties. The study includes fruits with different shapes (oblate, slightly flattened, rounded, heart-shaped, long oblong and pyriform), colors (yellow, pink and red) and sizes (very small to very large). In addition, black colored tomato fruits with yellow, pink or red background color were studied. The highest concentrations of lycopene, ß-carotene, phytoene and phytofluene were found in pink and red tomatoes, while the highest concentrations of lutein, violaxanthin, neoxanthin and chlorophylls were found in fruits with a dark coloration, regardless of their background coloration. Finally, the highest concentrations of the studied compounds as a whole (except ß-carotene) were found in red- and pink-black varieties. Findings will hopefully contribute to recovering many tomato traditional varieties for use, directly in the field or as donor parents for breeding programs, to increase the nutraceutical properties of commercial varieties.

Combination of solvent extractants for dispersive liquid-liquid microextraction of fungicides from water and fruit samples by liquid chromatography with tandem mass spectrometry.

A multiresidue method was developed to determine twenty-five fungicides belonging to three different chemical families, oxazoles, strobilurins and triazoles, in water and fruit samples, using dispersive liquid-liquid microextraction (DLLME) and liquid chromatography/tandem mass spectrometry (LC-MS2). Solid-liquid extraction with acetonitrile was used for the analysis in fruits, the extract being used as dispersant solvent in DLLME. Since some of the analytes showed high affinity for chloroform and the others were more efficiently extracted with undecanol, a mixture of both solvents was used as extractant in DLLME. After evaporation of CHCl3, the enriched phase was analyzed. Enrichment factors in the 23-119 and 12-60 ranges were obtained for waters and fruits, respectively. The approach was most sensitive for metominostrobin with limits of quantification of 1ngL-1 and 5ngkg-1 in waters and fruits, respectively, while a similar sensitivity was attained for tebuconazole in fruits. Recoveries of the fungicides varied between 86 and 116%.

Determination of spirocyclic tetronic/tetramic acid derivatives and neonicotinoid insecticides in fruits and vegetables by liquid chromatography and mass spectrometry after dispersive liquid-liquid microextraction.

Dispersive liquid-liquid microextraction was used to preconcentrate three spirocyclic tetronic/tetramic acid derivatives (spirotetramat, spiromesifen and spirodiclofen) and five neonicotinoid (thiamethoxam, chlotianidin, imidacloprid, acetamiprid and thiacloprid) insecticides previously extracted from fruit and vegetable matrices with acetonitrile. The organic enriched phase was evaporated, reconstituted in 25µL acetonitrile and analyzed by reversed-phase liquid chromatography with tandem mass spectrometry using a triple quadrupole in selected reaction monitoring mode. Enrichment factors in the 15-100 range were obtained. A matrix effect was observed, the detection limits varying between 0.025 and 0.5ngg(-1), depending on the compound and the sample matrix. The developed method was applied to the analysis of 25 samples corresponding to five different fruit and vegetable matrices. Only thiamethoxam was detected in a lemon sample at a concentration close to the quantification limit, and spiromesifen and spirotetramat at concentrations between 11.6 and 54.5ngg(-1).

Metabolite profile of the tomato dwarf cultivar Micro-Tom and comparative response to saline and nutritional stresses with regard to a commercial cultivar.

BACKGROUND: The dwarf tomato variety Micro-Tom has been used as a plant model for studies of plant development. However, its response to environmental and agricultural factors has not been well studied. This work studies the phytochemical content of Micro-Tom tomato and its comparative response to saline and nutritional (N, K and Ca) stresses with regard to a commercial variety. RESULTS: The chromatographic profiles of Micro-Tom were similar to those of the commercial variety and the only differences appear to be the concentration of the components. In Micro-Tom, the concentrations of sugars and organic acids increased by salinity in a lesser extent than in Optima. Moreover, contrary to that observed in the commercial variety, phenolic compounds and vitamin C did not increase by salinity in the dwarf variety. However, both varieties increased similarly the concentrations of carotenoids under saline conditions. Finally, fruit yield and most primary and secondary metabolite concentrations in Micro-Tom were not affected by N, K or Ca limitation. CONCLUSIONS: The mutations leading to the dwarf phenotype did not greatly alter the metabolite profiles but studies using Micro-Tom as a plant model should consider the lower capacity for sugars and organic acids under saline conditions and the greater tolerance to nutrient limitation of the dwarf variety.

Photodegradation of neonicotinoid insecticides in water by semiconductor oxides.

The photocatalytic degradation of three neonicotinoid insecticides (NIs), thiamethoxam (TH), imidacloprid (IM) and acetamiprid (AC), in pure water has been studied using zinc oxide (ZnO) and titanium dioxide (TiO2) as photocatalysts under natural sunlight and artificial light irradiation. Photocatalytic experiments showed that the addition of these chalcogenide oxides in tandem with the electron acceptor (Na2S2O8) strongly enhances the degradation rate of these compounds in comparison with those carried out with ZnO and TiO2 alone and photolytic tests. Comparison of catalysts showed that ZnO is the most efficient for the removal of such insecticides in optimal conditions and at constant volumetric rate of photon absorption. Thus, the complete disappearance of all the studied compounds was achieved after 10 and 30 min of artificial light irradiation, in the ZnO/Na2S2O8 and TiO2/Na2S2O8 systems, respectively. The highest degradation rate was noticed for IM, while the lowest rate constant was obtained for AC under artificial light irradiation. In addition, solar irradiation was more efficient compared to artificial light for the removal of these insecticides from water. The main photocatalytic intermediates detected during the degradation of NIs were identified.

Dispersive liquid-liquid microextraction for the determination of new generation pesticides in soils by liquid chromatography and tandem mass spectrometry.

A sensitive method for the determination of five new generation pesticides (chlorantraniliprole, spirotetramat, spiromesifen, spirodiclofen and flubendiamide) in soil samples has been developed using liquid chromatography and tandem mass spectrometry (LC-MS(2)) with a triple-quadrupole in the multiple reaction monitoring mode. The target analytes are released from the solid matrix by single-phase extraction in acetonitrile (SLE), this organic phase being used as dispersant solvent in the dispersive liquid-liquid microextraction (DLLME) step. The different parameters affecting the extraction efficiency in DLLME were carefully studied, being 1.5mL of acetonitrile extract (disperser solvent), 125µL carbon tetrachloride (extraction solvent) and 10mL aqueous solution, the selected conditions. The enriched organic phase was evaporated, reconstituted with 50µL acetonitrile and injected into a liquid chromatograph with a mobile phase composed of acetonitrile and 0.1% (v/v) formic acid under gradient elution and a C8 stationary phase. Detection limits in the 0.0015-0.0090ngg(-1) range were obtained. Insecticide concentrations ranging from 0.03 to 197ngg(-1), depending on the compound, were found in the soil samples analysed. The recovery values obtained by SLE-DLLME-LC-ESI-MS(2) for three spiked soils at three concentration levels varied between 87 and 114%, with RSDs of between 5.5 and 14%.

Increased temperature produces changes in the bioactive composition of tomato, depending on its developmental stage.

The present study examines the effect of an increased day temperature on vitamin C and carotenoid concentrations in tomato, depending on the developmental stage of fruits when the stress is imposed. Plants were cultivated in a growth chamber initially at 24 °C, and the day temperature was increased to 32 °C when fruits belonging to six different fruit development stages could be differentiated. Vitamin C, phytoene, phytofluene, lycopene, γ-carotene, and violaxantin concentrations were significantly lower when a temperature of 32 °C was imposed during the advanced stages of fruit development compared to the levels observed in the control treatment. However, no effect or increased concentrations were observed when the temperature was increased in earlier stages, indicating the adaptation of the plant metabolism to high temperature. Finally, no effect on ß-carotene concentration was observed, regardless of the fruit developmental stage when the temperature increase was applied.

Use of different organic wastes as strategy to mitigate the leaching potential of phenylurea herbicides through the soil.

In this study, the leaching of 14 substituted phenylurea herbicides (PUHs) through disturbed soil columns packed with three different soils was investigated in order to determine their potential for groundwater pollution. Simultaneously, a series of experiments were conducted to demonstrate the effect of four different organic wastes (composted sheep manure (CSM), composted pine bark (CPB), spent coffee grounds (SCG) and coir (CR)) on their mobility. All herbicides, except difenoxuron, showed medium/high leachability through the unamended soils. In general, addition of agro-industrial and composted organic wastes at a rate of 10% (w/w) increased the adsorption of PUHs and decreased their mobility in the soil, reducing their leaching. In all cases, the groundwater ubiquity score (GUS) index was calculated for each herbicide on the basis of its persistence (as t ½) and mobility (as K OC). The results obtained point to the interest in the use of agro-industrial and composted organic wastes in reducing the risk of groundwater pollution by pesticide drainage.

Minimization of methabenzthiazuron residues in leaching water using amended soils and photocatalytic treatment with TiO2 and ZnO.

In the present work, potential groundwater pollution by methabenzthiazuron (MTBU) and the effect of three different amendments (composted sheep manure, composted pine bark and spent coffee grounds) on its mobility were investigated under laboratory conditions. The efficiency of ZnO and TiO2 suspensions in the photocatalytic degradation of MTBU in leaching water was also investigated. The relative and cumulative breakthrough curves were obtained from disturbed soil columns. The presence and/or addition of organic matter drastically reduced the movement of the herbicide. On other hand, photocatalytic experiments showed that the addition of ZnO and TiO2 strongly enhances the degradation rate of this herbicide compared with the results of photolytic experiments under artificial light. ZnO appeared to be more effective in MTBU oxidation than TiO2. The results obtained point to the interest of using organic wastes and heterogeneous photocatalysis for reducing the pollution of groundwater by pesticide drainage.

Solarization and biosolarization using organic wastes for the bioremediation of soil polluted with terbuthylazine and linuron residues.

Strategies for remediation of polluted soils are needed to accelerate the degradation and natural attenuation of pesticides. This study was conducted to assess the effect of solarization (S) and biosolarization (BS) during the summer season using organic wastes (composted sheep manure and sugar beet vinasse) for the bioremediation of soil containing residues of terbuthylazine and linuron. The results showed that both S and BS enhanced herbicide dissipation rates compared with the non-disinfected control, an effect which was attributed to the increased soil temperature and organic matter. Linuron showed similar behavior under S and BS conditions. However, terbuthylazine was degraded to a greater extent in the biosolarization experiment using sugar beet vinasse than in the both the solarization and biosolarization experiments using composted sheep manure treatments. The main organic intermediates detected during the degradation of terbuthylazine and linuron were identified, enabling the main steps of degradation to be proposed. The results confirm that both S and BS techniques can be considered as a remediation tools for polluted soils containing these herbicides.

Use of different organic wastes in reducing the potential leaching of propanil, isoxaben, cadusafos and pencycuron through the soil.

In this study, we examined the effect of four different organic wastes (OW)-composted sheep manure (CSM), spent coffee grounds (SCG), composted pine bark (CPB) and coir (CR)-on the potential groundwater pollution of propanil and isoxaben (herbicides), cadusafos (insecticide) and pencycuron (fungicide) under laboratory conditions. For this purpose, leaching studies were conducted using disturbed soil columns filled with a clay loam soil (Hipercalcic calcisol). The addition of organic matter (OM) drastically reduced the movement of the studied pesticides. The results obtained point to the interest in the use of agro-industrial and composted OW in reducing the groundwater pollution by pesticide drainage.