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Gabriela Elena Viacava - One of the best experts on this subject based on the ideXlab platform.
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characterization of phenolic compounds in green and red oak Leaf Lettuce cultivars by uhplc dad esi qtof ms using mse scan mode
Journal of Mass Spectrometry, 2017Co-Authors: Gabriela Elena Viacava, Sara I. Roura, Luis A. Berrueta, C. Iriondo, Blanca Gallo, Rosa M AlonsosalcesAbstract:Lettuce (Lactuca sativa) is one of the most popular Leafy vegetables in the world and constitutes a major dietary source of phenolic compounds with health-promoting properties. In particular, the demand for green and red oak-Leaf Lettuces has considerably increased in the last years but few data on their polyphenol composition are available. Moreover, the usage of analytical edge technology can provide new structural information and allow the identification of unknown polyphenols. In the present study, the phenolic profiles of green and red oak-Leaf Lettuce cultivars were exhaustively characterized by ultrahigh-performance liquid chromatography (UHPLC) coupled online to diode array detection (DAD), electrospray ionization (ESI), and quadrupole time-of-flight mass spectrometry (QToF/MS), using the MSE instrument acquisition mode for recording simultaneously exact masses of precursor and fragment ions. One hundred fifteen phenolic compounds were identified in the acidified hydromethanolic extract of freeze-dried Lettuce leaves. Forty-eight of these compounds were tentatively identified for the first time in Lettuce, and only 20 of them have been previously reported in oak-Leaf Lettuce cultivars in literature. Both oak-Leaf Lettuce cultivars presented similar phenolic composition, except for apigenin-glucuronide and dihydroxybenzoic acid, only detected in the green cultivar; and for luteolin-hydroxymalonylhexoside, an apigenin conjugate with molecular formula C40 H54 O19 (monoisotopic MW = 838.3259 u), cyanidin-3-O-glucoside, cyanidin-3-O-(3″-O-malonyl)glucoside, cyanidin-3-O-(6″-O-malonyl)glucoside, and cyanidin-3-O-(6″-O-acetyl)glucoside, only found in the red cultivar. The UHPLC-DAD-ESI-QToF/MSE approach demonstrated to be a useful tool for the characterization of phenolic compounds in complex plant matrices.
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Characterization of phenolic compounds in green and red oak-Leaf Lettuce cultivars by UHPLC-DAD-ESI-QToF/MS using MSE scan mode.
Journal of mass spectrometry : JMS, 2017Co-Authors: Gabriela Elena Viacava, Sara I. Roura, Luis A. Berrueta, C. Iriondo, Blanca Gallo, Rosa M. Alonso-salcesAbstract:Lettuce (Lactuca sativa) is one of the most popular Leafy vegetables in the world and constitutes a major dietary source of phenolic compounds with health-promoting properties. In particular, the demand for green and red oak-Leaf Lettuces has considerably increased in the last years but few data on their polyphenol composition are available. Moreover, the usage of analytical edge technology can provide new structural information and allow the identification of unknown polyphenols. In the present study, the phenolic profiles of green and red oak-Leaf Lettuce cultivars were exhaustively characterized by ultrahigh-performance liquid chromatography (UHPLC) coupled online to diode array detection (DAD), electrospray ionization (ESI), and quadrupole time-of-flight mass spectrometry (QToF/MS), using the MSE instrument acquisition mode for recording simultaneously exact masses of precursor and fragment ions. One hundred fifteen phenolic compounds were identified in the acidified hydromethanolic extract of freeze-dried Lettuce leaves. Forty-eight of these compounds were tentatively identified for the first time in Lettuce, and only 20 of them have been previously reported in oak-Leaf Lettuce cultivars in literature. Both oak-Leaf Lettuce cultivars presented similar phenolic composition, except for apigenin-glucuronide and dihydroxybenzoic acid, only detected in the green cultivar; and for luteolin-hydroxymalonylhexoside, an apigenin conjugate with molecular formula C40 H54 O19 (monoisotopic MW = 838.3259 u), cyanidin-3-O-glucoside, cyanidin-3-O-(3″-O-malonyl)glucoside, cyanidin-3-O-(6″-O-malonyl)glucoside, and cyanidin-3-O-(6″-O-acetyl)glucoside, only found in the red cultivar. The UHPLC-DAD-ESI-QToF/MSE approach demonstrated to be a useful tool for the characterization of phenolic compounds in complex plant matrices.
Charles R Caldwell - One of the best experts on this subject based on the ideXlab platform.
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Effect of supplemental ultraviolet radiation on the carotenoid and chlorophyll composition of green house-grown Leaf Lettuce (Lactuca sativa L.) cultivars
Journal of Food Composition and Analysis, 2006Co-Authors: Charles R Caldwell, Steven J. BritzAbstract:Abstract Eight green Leaf and eight red Leaf Lettuce varieties were grown in a greenhouse under control, receiving supplemental ultraviolet-A (UV-A) (320–400 nm) and supplemental UV-A plus ultraviolet-B (UV-B) (290–320 nm) radiation. The edible portion of the Lettuce was frozen, lyophilized and extracted in 80% aqueous acetone for carotenoid and chlorophyll content determination by reverse-phase HPLC. Lutein was the major carotenoid in the Lettuce samples with lesser amounts of β-carotene and neoxanthin. In general, supplemental UV-B increased the carotenoid and chlorophyll concentration of green Leaf Lettuce, while reducing the levels of these compounds in red Leaf Lettuce. Varieties with relatively high levels of lutein also had high levels of chlorophyll a. Pheophytin a and b levels were higher in green Leaf Lettuce relative to the red Leaf varieties. The up to 10-fold cultivar-specific differences in the levels of the carotenoids in plants grown under identical conditions suggests that the selection of specific Leaf Lettuce varieties for greenhouse production may enhance their nutritional benefits.
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Effect of supplemental ultraviolet radiation on the concentration of phytonutrients in green and red Leaf Lettuce (Lactuca sativa) cultivars
Ultraviolet Ground- and Space-based Measurements Models and Effects V, 2005Co-Authors: Steven J. Britz, Charles R Caldwell, Roman M. Mirecki, James R. Slusser, Wei GaoAbstract:Eight cultivars each of red and green Leaf Lettuce were raised in a greenhouse with supplemental UV radiation, either UV-A (wavelengths greater than ca. 315 nm) or UV-A+UV-B (wavelengths greater than ca. 290 nm; 6.4 kJ m -2 daily biologically effective UV-B), or no supplemental UV (controls). Several phytonutrients were analyzed in Leaf flours to identify lines with large differences in composition and response to UV-B. Red Leaf Lettuce had higher levels of phenolic acid esters, flavonols and anthocyanins than green lines. Both green and red lines exposed to UV-B for 9 days showed 2-3-fold increases in flavonoids compared to controls, but only 45% increases in phenolic acid esters, suggesting these compounds may be regulated by different mechanisms. There were large differences between cultivars in levels of phenolic compounds under control conditions and also large differences in UV-B effects. Among red varieties, cv. Galactic was notable for high levels of phenolics and a large response to UV-B. Among green varieties, cvs. Black-Seeded Simpson and Simpson Elite had large increases in phenolics with UV-B exposure. Photosynthetic pigments were also analyzed. Green Leaf Lettuce had high levels of pheophytin, a chlorophyll degradation product. Total chlorophylls (including pheophytin) were much lower in green compared to red varieties. Lutein, a carotenoid, was similar for green and red lines. Total chlorophylls and lutein increased 2-fold under supplemental UV-B in green lines but decreased slightly under UV-B in red lines. Lettuce appears to be a valuable crop to use to study phytochemical-environment interactions.
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alkylperoxyl radical scavenging activity of red Leaf Lettuce lactuca sativa l phenolics
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Charles R CaldwellAbstract:Although Lettuce may provide relatively low levels of antioxidative phytochemicals which may contribute to human health, Lettuce Leaf extracts in fact contained compounds with high specific peroxyl radical scavenging activities. After determining the extraction conditions that minimized phenolic oxidation and produced the highest oxygen radical absorbance capacity (ORAC) values, the phenolic compounds from red Leaf Lettuce were separated by reverse-phase high-performance liquid chromatography (HPLC). The primary phenolic compounds in the Leaf tissue extracts were mono- and dicaffeoyltartaric acid (CTA and DCTA), mono- and dicaffeoylquinic acid (CQA and DCQA), quercetin 3-malonylglucoside (QMG), quercetin 3-glucoside (QG), cyanidin 3-malonylglucoside (CMG), and an unknown phenolic ester (UPE). Significant levels of DCQA were only found after wounding. Using the new fluorescein-based ORAC assay procedures, fractions from the HPLC analyses were assayed for peroxyl radical absorbance capacity. Using absorbanc...
Thomas A. Doerge - One of the best experts on this subject based on the ideXlab platform.
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Nitrogen and Water Interactions in Subsurface Trickle-Irrigated Leaf Lettuce II. Agronomic, Economic, and Environmental Outcomes
Soil Science Society of America Journal, 1996Co-Authors: Thomas L. Thompson, Thomas A. DoergeAbstract:Evaluation of trickle-irrigated crop production systems should address agronomic, economic, and environmental outcomes. The objectives of this research were to : (i) determine plant N uptake, residual soil inorganic N, unutilized fertilizer N, and unaccounted fertilizer N for subsurface trickle irrigated Leaf Lettuce (Lactuca sativa L. cv. Waldmann's Green), and (ii) use spatial analysis techniques to simultaneously evaluate agronomic, economic, and environmental production criteria for Leaf Lettuce within one growing season. Field experiments were conducted using buried trickle irrigation during three winter growing seasons in southern Arizona. Deficient to excessive N (35-300 kg ha -1 ) and target soil water tension (SWT) treatments (12.0-4.0 kPa) were applied in factorial combinations each year. Fertilizer N recovery was determined by the difference method. Spatial analysis of response surfaces was used to determine overlap of zones with acceptable values for marketable yield, net economic return, and unaccounted fertilizer N for Leaf Lettuce during 1992-1993. Maximum unutilized fertilizer N was 216 kg ha -1 for Leaf Lettuce, and maximum unaccounted fertilizer N was 149 kg ha -1 . Unutilized fertilizer N and unaccounted fertilizer N increased sharply when adequate N and water rates were exceeded. Spatial analysis of response surfaces for 1992-1993 showed a small region bounded by 6.6 to 7.3 kPa SWT and 238 to 252 kg N ha -1 that would have resulted in >95% of maximum predicted marketable yield and net return while limiting NO 3 -N concentrations in drainage water to ≤10 mg L -1 .
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Nitrogen and Water Interactions in Subsurface Trickle-Irrigated Leaf Lettuce: I. Plant Response
Soil Science Society of America Journal, 1996Co-Authors: Thomas L. Thompson, Thomas A. DoergeAbstract:Rising water costs and concerns about groundwater contamination by NO 3 - are forcing growers in arid regions to adopt practices to improve water and N use efficiency. Subsurface trickle irrigation offers the ability to precisely deliver appropriate amounts of water and N to the crop root zone. The objectives of this research were to : (i) determine the optimum level (with respect to marketable yield) of soil water tension for subsurface trickle-irrigated Leaf Lettuce (Lactuca sativa L. cv. Waldmann's Green), (ii) determine N by water interactions on crop yield and quality, and (iii) determine seasonal patterns of crop N uptake. Three field experiments were conducted during the 1990 to 1993 winter growing seasons on a Casa Grande soil (fine-loamy, mixed, hyperthermic, Typic Natriagid [reclaimed]) in southern Arizona. Deficient to excessive N (35-300 kg ha - 1 ) and target soil water tension (SWT) treatments (12.0-4.0 kPa) were applied in factorial combinations each year. Maximum marketable Leaf Lettuce yields observed were 54.0 Mg ha -1 . Nitrogen rates associated with maximum yields ranged from 120 to 300 kg ha -1 , and depended on average SWT. Excessive irrigation (5.3 kPa average SWT) resulted in lower yields, head weight, and head length. Marketable yields showed a pronounced water x N interaction, but yield quality (head length and weight) did not. Maximum N flux was 4.3 kg ha -1 d -1 , and an average of 75% of total N accumulation occurred in the 38 d prior to harvest. Results suggest that the soil water tension at 0.3-m depth should be maintained at 6 to 7 kPa for optimum yields of trickle-irrigated Leaf Lettuce.
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The Response of Leaf Lettuce to Phosphorous Fertilizer Placement and Rate
Vegetable Report, 1994Co-Authors: Kevin H. Pritchard, Thomas A. Doerge, Ted W. MccrearyAbstract:A one-year field study was conducted at the Maricopa Agricultural Center in the winter and spring of 1991 -92 with the purpose of comparing the response of Leaf Lettuce grown with subsurface drip irrigation to various broadcast and banded phosphorus (P) fertilizer applications and rates. Two rates of banded treble superphosphate , 250 lbs. (1X) and 125 lbs. (1 /2X) of P2Osper acre, were applied immediately before planting in a concentrated strip 1 inch directly below the row to be seeded. One broadcast rate, 250 lbs. (1X) of P205 per acre of the same material, was applied and folded into the planting beds during listing. Control plots, in which zero P fertilizer was applied, were also maintained. Whole plant total P concentrations were higher in the first one -third of the growing season for the band treatments, though the differences in responses between band and broadcast applications were not statistically significant in the final third of the season. The 1X band treatment exhibited both greater plant heights and diameters than all other treatments during the first one -half of the growing season, and maintained greater height dimensions in the second half. The 1X broadcast and 1/2X band treatments exhibited similar growth throughout the season. By harvest there were not significant differences in head or plant size or in marketable yield among the three P treatments.
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Nitrogen Management in Drip Irrigated Leaf Lettuce, Spinach and Green Crops
Vegetable Report, 1992Co-Authors: Thomas A. Doerge, Kevin H. Pritchard, Ted W. MccrearyAbstract:Preliminary nit s: (N) management experiments with spinach, Leaf lemece,romaine collard and mustard were conducted on a Casa Grande el. soil at the Maricopa Agricultural Center in the winter and spring of 1990 -91. The purpose of this N rate experiment was to develop initial Best Management strategies for N fertilizer use for emerging high vahte crops grown in Arizona using subsurface drip irrigation. Three rates of urea,ammonium nitrate were applied to each cultivar to provide deficient (N1), adequate (N2) and supraopti real (N3) levels of N. All cultivars responded dramatically to the application of N. Fresh weight yields in the NI and N2 treatments averaged 45 and 53% of the N3 treatment The average N3 yields recorded in these trials were 23.1, 128 and 21.8 tons of marketable produce per acre for greens, spinach and Leaf Lettuce /romaine crops, respectively. Preliminary plant tissue test results indicated that for all five crops, whole plant total N (TN) levels and midrib + petiole NOrN and Leaf blade TN concentrations in the youngest mature Leaf were responsive to differences in soil N supply and show promise as diagnostic N tissue test procedures. The midrib + petiole NOrN test appeared to be the best indicator of plant N status throughout the growing season for all five crops studied Introduction The research base needed to formulate nitrogen (N) fertilizer BMP's for most of the major acreage crops grown in Arizona is adequate. Tissue testing procedures for monitoring the in season nitrogen needs of cotton, small grains, melons, head Lettuce and a number of other major vegetables are currently available. However, nitrogen management for virtually all emerging "new crops' is not well documented and needs further study. These are primarily high -value vegetable and specialty crops such as bok choy, greens, Leaf Lettuce, parsley, rapini, romaine, spinach and squash. The objective of this research was to develop initial Best Management strategies for nitrogen fertilizer usage in emerging high value crops grown in Arizona, specifically Leaf Lettuce, romaine, spinach, collard and mustard. Materials and Methods Field trials were initiated in the fall of 1990 at the Maricopa Agricultural Center (MAC) to develop nitrogen Best Management Practices (BMP's) for three high value vegetable crops. Leading commercial varieties of Leaf Lettuce (Waldmann's Green), romaine (Parris Island Cos), spinach (Crystal Savoy and Indian Summer), collard (Vates) and mustard (Southern Giant) were planted on 25 October. The experimental design for each of the five crops was a randomized complete block with four replications. Three rates of N were applied to provide deficient (N1), adequate (N2) and supraoptimum (N3) N as shown in Table 1. The soil type in the experimental area was a Casa Grande sandy loam with a preplant soil test NO3 -N level of 1.2 ppm. This is considered an extremely low value.
Steven J. Britz - One of the best experts on this subject based on the ideXlab platform.
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Effect of supplemental ultraviolet radiation on the carotenoid and chlorophyll composition of green house-grown Leaf Lettuce (Lactuca sativa L.) cultivars
Journal of Food Composition and Analysis, 2006Co-Authors: Charles R Caldwell, Steven J. BritzAbstract:Abstract Eight green Leaf and eight red Leaf Lettuce varieties were grown in a greenhouse under control, receiving supplemental ultraviolet-A (UV-A) (320–400 nm) and supplemental UV-A plus ultraviolet-B (UV-B) (290–320 nm) radiation. The edible portion of the Lettuce was frozen, lyophilized and extracted in 80% aqueous acetone for carotenoid and chlorophyll content determination by reverse-phase HPLC. Lutein was the major carotenoid in the Lettuce samples with lesser amounts of β-carotene and neoxanthin. In general, supplemental UV-B increased the carotenoid and chlorophyll concentration of green Leaf Lettuce, while reducing the levels of these compounds in red Leaf Lettuce. Varieties with relatively high levels of lutein also had high levels of chlorophyll a. Pheophytin a and b levels were higher in green Leaf Lettuce relative to the red Leaf varieties. The up to 10-fold cultivar-specific differences in the levels of the carotenoids in plants grown under identical conditions suggests that the selection of specific Leaf Lettuce varieties for greenhouse production may enhance their nutritional benefits.
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Effect of supplemental ultraviolet radiation on the concentration of phytonutrients in green and red Leaf Lettuce (Lactuca sativa) cultivars
Ultraviolet Ground- and Space-based Measurements Models and Effects V, 2005Co-Authors: Steven J. Britz, Charles R Caldwell, Roman M. Mirecki, James R. Slusser, Wei GaoAbstract:Eight cultivars each of red and green Leaf Lettuce were raised in a greenhouse with supplemental UV radiation, either UV-A (wavelengths greater than ca. 315 nm) or UV-A+UV-B (wavelengths greater than ca. 290 nm; 6.4 kJ m -2 daily biologically effective UV-B), or no supplemental UV (controls). Several phytonutrients were analyzed in Leaf flours to identify lines with large differences in composition and response to UV-B. Red Leaf Lettuce had higher levels of phenolic acid esters, flavonols and anthocyanins than green lines. Both green and red lines exposed to UV-B for 9 days showed 2-3-fold increases in flavonoids compared to controls, but only 45% increases in phenolic acid esters, suggesting these compounds may be regulated by different mechanisms. There were large differences between cultivars in levels of phenolic compounds under control conditions and also large differences in UV-B effects. Among red varieties, cv. Galactic was notable for high levels of phenolics and a large response to UV-B. Among green varieties, cvs. Black-Seeded Simpson and Simpson Elite had large increases in phenolics with UV-B exposure. Photosynthetic pigments were also analyzed. Green Leaf Lettuce had high levels of pheophytin, a chlorophyll degradation product. Total chlorophylls (including pheophytin) were much lower in green compared to red varieties. Lutein, a carotenoid, was similar for green and red lines. Total chlorophylls and lutein increased 2-fold under supplemental UV-B in green lines but decreased slightly under UV-B in red lines. Lettuce appears to be a valuable crop to use to study phytochemical-environment interactions.
Rosa M. Alonso-salces - One of the best experts on this subject based on the ideXlab platform.
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Characterization of phenolic compounds in green and red oak-Leaf Lettuce cultivars by UHPLC-DAD-ESI-QToF/MS using MSE scan mode.
Journal of mass spectrometry : JMS, 2017Co-Authors: Gabriela Elena Viacava, Sara I. Roura, Luis A. Berrueta, C. Iriondo, Blanca Gallo, Rosa M. Alonso-salcesAbstract:Lettuce (Lactuca sativa) is one of the most popular Leafy vegetables in the world and constitutes a major dietary source of phenolic compounds with health-promoting properties. In particular, the demand for green and red oak-Leaf Lettuces has considerably increased in the last years but few data on their polyphenol composition are available. Moreover, the usage of analytical edge technology can provide new structural information and allow the identification of unknown polyphenols. In the present study, the phenolic profiles of green and red oak-Leaf Lettuce cultivars were exhaustively characterized by ultrahigh-performance liquid chromatography (UHPLC) coupled online to diode array detection (DAD), electrospray ionization (ESI), and quadrupole time-of-flight mass spectrometry (QToF/MS), using the MSE instrument acquisition mode for recording simultaneously exact masses of precursor and fragment ions. One hundred fifteen phenolic compounds were identified in the acidified hydromethanolic extract of freeze-dried Lettuce leaves. Forty-eight of these compounds were tentatively identified for the first time in Lettuce, and only 20 of them have been previously reported in oak-Leaf Lettuce cultivars in literature. Both oak-Leaf Lettuce cultivars presented similar phenolic composition, except for apigenin-glucuronide and dihydroxybenzoic acid, only detected in the green cultivar; and for luteolin-hydroxymalonylhexoside, an apigenin conjugate with molecular formula C40 H54 O19 (monoisotopic MW = 838.3259 u), cyanidin-3-O-glucoside, cyanidin-3-O-(3″-O-malonyl)glucoside, cyanidin-3-O-(6″-O-malonyl)glucoside, and cyanidin-3-O-(6″-O-acetyl)glucoside, only found in the red cultivar. The UHPLC-DAD-ESI-QToF/MSE approach demonstrated to be a useful tool for the characterization of phenolic compounds in complex plant matrices.