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Carlos Baixauli - One of the best experts on this subject based on the ideXlab platform.
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sensory quality bioactive constituents and microbiological quality of green and red fresh cut Lettuces lactuca sativa l are influenced by soil and soilless agricultural production systems
Postharvest Biology and Technology, 2012Co-Authors: Maria V Selma, Maria C Luna, Ascension Martinezsanchez, Juan A Tudela, David Beltran, Carlos BaixauliAbstract:Abstract Quality characteristics and shelf-life of fresh-cut Lettuce cultivated in soil, as the traditional production system, and soilless, as an innovative production system, were investigated. Three Lettuce genotypes, lollo rosso and red oak leaf as red-leafed genotypes, and butterhead as a green-leafed genotype, were studied. Lettuces from both production systems were grown in the same open field and at the same time in the winter season. A longer growing period was needed, to obtain the same maturity stage, in the soil than in the soilless (102 and 63 d after planting, respectively). After harvest, the visual quality of the fresh-cut produce from red-leafed Lettuce cultivated in soilless was better than those in soil. In the case of green-leafed genotype, the soilless system gave a lower visual quality of the fresh-cut product. Lollo rosso cultivated in the soilless system had a higher content of phytochemicals, including vitamin C and individual and total phenolics, than that cultivated in soil. At the end of storage, fresh-cut lollo rosso and red oak leaf grown in the soilless system showed significantly higher content of vitamin C than those in soil. This high content of antioxidants was linked to a better maintenance of visual quality and the control of browning when compared with the fresh-cut product from Lettuces cultivated in soil. The soilless system was more effective in controlling microbial contamination as Lettuce cultivated in the soilless system had a lower initial microbial load and slower microbial growth during storage. At the end of shelf-life, differences in microbial counts between soil and soilless Lettuce were 3 and 1.5 log units higher for lactic acid bacteria and total coliforms, respectively, in soil. This study shows that higher quality and microbiologically safer raw product can be provided by the soilless system as a new growing system although it depends on the genotype and the season.
Chieri Kubota - One of the best experts on this subject based on the ideXlab platform.
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effect of methyl jasmonate on phenolic compounds and carotenoids of romaine Lettuce lactuca sativa l
Journal of Agricultural and Food Chemistry, 2007Co-Authors: Jorge M Fonseca, Ju Hee Choi, Chieri KubotaAbstract:The effect of exogenous methyl jasmonate (MeJA) on antioxidative compounds of romaine Lettuce (Lactuca sativa L.) was investigated. Lettuces were treated with various MeJA solutions (0, 0.05, 0.1, 0.25, and 0.5 mM) before harvest. Total phenolic compounds content and antioxidant capacity of romaine Lettuce significantly increased after MeJA treatments (0.1, 0.25, and 0.5 mM). The total content of phenolic compounds of the romaine Lettuce treated with 0.5 mM MeJA (31.6 µg of gallic acid equivalents/mg of dry weight) was 35% higher than that of the control. The increase in phenolic compound content was attributed to a caffeic acid derivative and an unknown phenolic compound, which also contributed to increased antioxidant capacity. The induction of phenylalanine ammonia-lyase (PAL) activity by the MeJA treatment indicated that phenolic compounds were altered due to the activation of the phenylpropandoid pathway. Total content of carotenoids, including lutein and β-carotene, of the MeJA-treated Lettuce did n...
M Castellari - One of the best experts on this subject based on the ideXlab platform.
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analysis of eleven phenolic compounds including novel p coumaroyl derivatives in Lettuce lactuca sativa l by ultra high performance liquid chromatography with photodiode array and mass spectrometry detection
Analytical Abstracts, 2012Co-Authors: Albert Ribasagusti, M Gratacoscubarsi, C Sarraga, J A Garciaregueiro, M CastellariAbstract:Lettuce is a widely consumed vegetable and a good source of phenolic compounds. Several factors (genetic, agronomical and environmental) can influence the Lettuce composition; their effects are not completely defined and more studies are needed on this topic. To develop an improved ultra-high-performance liquid chromatography (UHPLC) method to quantify the main target intact phenolic compounds in Lettuce. UHPLC identification of the compounds was supported by PAD spectra and MSn analyses. Quantification was carried out by PAD, by creating matrix-matched calibration curves at the specific wavelength for each compound. Sample pretreatment was simplified, with neither purification nor hydrolysis steps. Chromatographic conditions were chosen to minimise matrix interferences and to give a suitable separation of the major phenolic compounds within 27 min. The method allowed the quantification of 11 intact phenolic compounds in Romaine Lettuces, including phenolic acids (caffeoyl and p-coumaroyl esters) and flavonoids (quercetin glycosides). Four p-coumaroyl esters were tentatively identified and quantified for the first time in Lettuce. The main intact phenolic compounds, including four novel p-coumaroyl esters, were simultaneously quantified in Lettuce with optimal performances and a reduced total time of analysis. These findings make headway in the understanding of the Lettuce phytochemicals with potential nutritional relevance.
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analysis of eleven phenolic compounds including novel p coumaroyl derivatives in Lettuce lactuca sativa l by ultra high performance liquid chromatography with photodiode array and mass spectrometry detection
Phytochemical Analysis, 2011Co-Authors: Albert Ribasagusti, M Gratacoscubarsi, C Sarraga, J A Garciaregueiro, M CastellariAbstract:Introduction Lettuce is a widely consumed vegetable and a good source of phenolic compounds. Several factors (genetic, agronomical and environmental) can influence the Lettuce composition; their effects are not completely defined and more studies are needed on this topic. Objective To develop an improved ultra-high-performance liquid chromatography (UHPLC) method to quantify the main target intact phenolic compounds in Lettuce. Methodology UHPLC identification of the compounds was supported by PAD spectra and MSn analyses. Quantification was carried out by PAD, by creating matrix-matched calibration curves at the specific wavelength for each compound. Results Sample pretreatment was simplified, with neither purification nor hydrolysis steps. Chromatographic conditions were chosen to minimise matrix interferences and to give a suitable separation of the major phenolic compounds within 27 min. The method allowed the quantification of 11 intact phenolic compounds in Romaine Lettuces, including phenolic acids (caffeoyl and p-coumaroyl esters) and flavonoids (quercetin glycosides). Four p-coumaroyl esters were tentatively identified and quantified for the first time in Lettuce. Conclusion The main intact phenolic compounds, including four novel p-coumaroyl esters, were simultaneously quantified in Lettuce with optimal performances and a reduced total time of analysis. These findings make headway in the understanding of the Lettuce phytochemicals with potential nutritional relevance.
Joan A Dusky - One of the best experts on this subject based on the ideXlab platform.
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spiny amaranth amaranthus spinosus l a serious competitor to crisphead Lettuce lactuca sativa l
Hortscience, 1996Co-Authors: James W Shrefler, William M Stall, Joan A DuskyAbstract:Three field studies on high-organic-matter soils were conducted to determine the zone of influence of spiny amaranth on Lettuce head quality. Spiny amaranth reduced Lettuce head firmness at all distances from the weed, ≤105 cm. Lettuce ribbiness increased at 15 and 45 cm compared with the weed-free control. Untrimmed Lettuce head weight was not affected by spiny amaranth presence beyond 45 cm. Trimmed Lettuce head weight was reduced at all distances compared with the control. Stem diameter and core length were not affected by spiny amaranth competition. The presence of a single spiny amaranth plant significantly influenced some Lettuce quality traits at ≤105 cm.
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effects of phosphorus fertility on competition between Lettuce lactuca sativa and spiny amaranth amaranthus spinosus
Weed Science, 1994Co-Authors: James W Shrefler, Barry J. Brecke, Joan A Dusky, David G. Shilling, Charles A. SanchezAbstract:Field studies were conducted to detennine the influence of phosphorus (P) fertility and method of application (banded versus broadcast) on the competitive interaction of Lettuce and spiny amaranth. Weed density significantly affected Lettuce head weight and spiny amaranth shoot biomass after 5 wk of interference. Weed density and duration of interference had little or no effect on P content of Lettuce tissue. Duration of interference did affect P concentration of spiny amaranth; however, weed density did not. Spiny amaranth competition reduced Lettuce yield, but P was not the limiting factor. Duration of interference and method of P application interactively affected Lettuce head weight; however, only duration of interference affected spiny amaranth biomass. Seven wk of interference caused a decrease in Lettuce head weight of 20, 8, and 24% when P was broadcast, banded, or not applied, respectively. Banding of P reduced the negative impact of spiny amaranth on Lettuce. Although method of P application influenced the interaction between Lettuce and spiny amaranth, interspecific competition between the two species probably was not due to competition for P but some other factor. Nomenclature: Lettuce, Lactuca sativa L., 'Southbay,' spiny amaranth,Amaranthus spinosus L. #3 AMASP. Additional index words: Intraspecific competition, interspecific competition, weed/crop interference, AMASP.
Claudinei Fonseca Souza - One of the best experts on this subject based on the ideXlab platform.
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effects of treated wastewater irrigation on soil properties and Lettuce yield
Agricultural Water Management, 2017Co-Authors: Vanessa Ribeiro Urbano, Thais Grandizoli Mendonca, Reinaldo Gaspar Bastos, Claudinei Fonseca SouzaAbstract:Domestic effluents may contain important nutrients for agricultural crop development, and reusing this effluent on irrigation can reduce the potable water demand, recycle nutrients, and decrease effluent discharges on water bodies. This study evaluated the changes on physical, chemical and microbiological characteristics of a Dusky Red Latosol, the yield and the quality of Lettuce after cultivation with treated wastewater on irrigation. In a greenhouse, Lettuces were irrigated using drinking water with conventional fertilization (T1) and treated wastewater with partial conventional fertilization (T2). After the Lettuce harvest, the physical, chemical and microbiological properties of soil, the nutrients, and the microbiological quality of Lettuce leaves were evaluated. Sodium adsorption ratio, magnesium, calcium, sodium, potassium, nitrate, chlorate, pH, electrical conductivity, total coliforms, Escherichia coli, chemical and biochemical oxygen demand were analyzed in irrigation water. The concentration of some soil nutrients (K, Ca, H, Al, and S) increased after irrigation with T2, and the presence of E. coli bacteria was not observed on Lettuce leaves or in the soil. The T2 did not damage the physical properties of soil and increased its nutrients. Lettuce production (in terms of fresh weight) was higher in Lettuce cultivated on T2 than that cultivated on T1. The treated wastewater quality was appropriate for Lettuce drip irrigation.
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Evaluation of sanitary quality of Lettuce (Lactuca sativa, L.) irrigated with reused water in comparison with commercialized Lettuce
Ambiente E Agua - An Interdisciplinary Journal of Applied Science, 2011Co-Authors: Antonio Claudio Testa Varallo, Joseane Marioto De Souza, Simone Sano Rossi De Rezende, Claudinei Fonseca SouzaAbstract:Inadequate use of water resources reduces their availability and therefore, research focused on their reutilization is required. This work evaluated the sanitary quality of Lettuce irrigated with reused water in comparison with samples of Lettuce commercialized in Taubate (SP) market. An experiment was developed in a greenhouse with three beds of Lettuce irrigated with reused water and three beds of Lettuce irrigated with urban water supply. After Lettuce biological cycle had been completed, Lettuce samples were collected from the beds (irrigated and non-irrigated with reused water) and from samples of Lettuce commercialized in the city market that were analyzed in the laboratory. The analyses were done using the multiple tubes methodology. The results showed that the samples from Lettuce irrigated with urban water supply were not contaminated by either total or thermotolerant coliforms while samples of irrigated Lettuce with reused water were contaminated by total coliforms. Samples from commercialized Lettuce were contaminated by both kinds of coliforms. Results indicated that the application of reused water for agricultural purposes should occur only after carefully treatment to allow a safe use and to contribute to the water use sustainability.
