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Margaret D. Collins, Loide Mayer Wasmund, and Paul W. Bosland

Chromatography Division, South San Francisco, Calif., for technical assistance on fluorescence detector wavelength scans; and Linda Rouse, associate chemist, McCormick and Co., Hunt Valley, Md., for high-performance liquid chromatography–mass spectrometry

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Ni Jia, Qing-Yan Shu, Dan-Hua Wang, Liang-Sheng Wang, Zheng-An Liu, Hong-Xu Ren, Yan-Jun Xu, Dai-Ke Tian, and Kenneth Michael Tilt

objective of our study was to identify and characterize the anthocyanins in herbaceous peony species from different regions of the world using reverse-phase high-performance liquid chromatography (HPLC) with diode array detection in tandem with electrospray

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Kevin A. Lombard, Emmanuel Geoffriau, and Ellen Peffley

Direct spectrophotometric determination of quercetin content in onions (Allium cepa L.) was investigated as a possible alternative to high-performance liquid chromatography (HPLC) analysis. Quercetin content in five onion varieties was monitored at 362 nm and quantified using simple spectrophotometric and HPLC methods. HPLC revealed that 3,4'-Qdg and 4'-Qmg comprised up to 93% of total flavonol content detected in the studied varieties. These major quercetin conjugates combined (3,4'-Qdg + 4'-Qmg) and total flavonol conjugates quantified by HPLC correlated closely with spectrophotometer values. Correlation coefficients were 0.96 (P < 0.0001) for 3,4'-Qdg + 4'-Qmg and 0.97 (P < 0.0001) for total flavonol conjugates in onion. Simple spectrophotometric procedure proved to be a valid, efficient, and cost-effective method for the quantification of total quercetin in onion. Chemical names used: quercetin-3,4'-O-diglucoside (3,4'-Qdg); quercetin-4'-O-glucoside (4'-Qmg).

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Jorge Siller-Cepeda, Alfonso Sánchez, Francisco Vázquez, Manuel Báez, René Palacios, Elsa Bringas, Evelia Araiza, and Reginaldo Báez

A rapid and sensitive high performance liquid chromatography method for quantifying simultaneously sucrose, fructose and glucose in fruits and vegetables is reported. Samples were extracted in 95% ethanol, homogenized and treated at 95C for 20 min. The supernatant was stored at -20C overnight and filtered through a G-25 Sephadex column. Aliquots were evaporated, redissolved in water, filtered, and injected. A Sorbex NH2 column operated at room temperature was used for separations. The sugars were detected at 192 nm. The retention times were 4.8, 5.9 and 10.3 min for fructose, glucose and sucrose, respectively. The method was applied to twenty-one fruit and vegetable species with different maturity stages. In addition, quality characteristics such as firmness, pH, acidity, soluble solids and color were evaluated. Main sugars for the different samples varied among species. In temperate fruits, fructose and glucose were the predominant sugars, while in tropical and subtropical fruits, the main sugar was sucrose. On the sampled vegetables, fructose was the primary sugar, although at very low levels. Quality characteristics coincided with sugar levels found among the different species.

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Rosanna Freyre, Chad Uzdevenes, Liwei Gu, and Kenneth H. Quesenberry

with white corollas with purple throat and an individual with pink corollas. We were then able to elucidate the genetic control for flower color in this species. We also performed high-performance liquid chromatography mass spectrometry analyses to

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Panthip Boonsong, Natta Laohakunjit, Orapin Kerdchoechuen, and Frank B. Matta

Fourteen Thai herbal plants were extracted using methanol, ethanol, and acetone. Comparison of the various extraction methods for pigments and polyphenols (colorants) showed that methanol provided a more complete extraction than ethanol and acetone. Percentage yield ranged from 1.7 to 40.7 and was dependent on the plant extracted and solubility of pigments and polyphenols (colorants) extracted by the various solvents. The absorption spectra of pigments and polyphenols (colorants) in the plant extract were present in the visible region (351 to 665 nm) and the absorption spectra of polyphenols were present in the ultraviolet region (200 to 349 nm). Color of plant extracts varied and included violet–blue, yellow–green, red, orange–red, gray–purple, blue–green, gray–orange, gray–yellow, and black. High-performance liquid chromatography (HPLC) was used to separate and identify compounds of plant pigments and polyphenols (colorants). Ya-nang had the greatest number of peaks and chlorophyll A and chlorophyll B were found only in Ya-nang. Numerous pigments and polyphenols were detected. Such compounds have the potential to be used as coloring dyes.

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Cary Pirone, Jodie V. Johnson, J. Martin E. Quirke, Horacio A. Priestap, and David Lee

, a close relative of S. reginae ( Pirone et al., 2009 ). Bilirubin was previously known in the animal kingdom where it is produced as a breakdown product of heme. Preliminary high-performance liquid chromatography (HPLC) and ultraviolet

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Hyungmin Rho, Paul Colaizzi, James Gray, Li Paetzold, Qingwu Xue, Bhimanagouda Patil, and Charles Rush

, flavonoids, ascorbic acid, dehydroascorbic acid, carotenoids, carbohydrates, and capsaicinoid contents of fruits were analyzed by high-performance liquid chromatography (HPLC). For tomatoes, basic quality attributes (titrable acidity, Brix, and pH) and

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Peter Boches, Brooke Peterschmidt, and James R. Myers

cultivars. Fig. 1. Phenolic content (mg/100 g fresh weight, measured by high-performance liquid chromatography–photodiode array) of S. l. var. cerasiforme accessions. Values are the mean of three biological replicates; error bars = 1 se . Means sharing

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Adriana Canto-Flick, Eduardo Balam-Uc, Jericó Jabìn Bello-Bello, Carlos Lecona-Guzmán, Daniela Solís-Marroquín, Susana Avilés-Viñas, Eunice Gómez-Uc, Guadalupe López-Puc, Nancy Santana-Buzzy, and Lourdes Georgina Iglesias-Andreu

al., 1977 ), and high-performance liquid chromatography ( Weaver and Awde, 1986 ). Of these, high-pressure liquid chromatography (HPLC) is considered the most reliable and rapid method ( Yao et al., 1994 ) available for the identification and