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William M. Randle, Jane E. Lancaster, Martin L. Shaw, Kevin H. Sutton, Rob L. Hay, and Mark L. Bussard

Three onion (Allium cepa L.) cultivars were grown to maturity at five S fertility levels and analyzed for S-alk(en)yl-L-cysteine sulfoxide (ACSO) flavor precursors, γ-glutamyl peptide (γ-GP) intermediates, bulb S, pyruvic acid, and soluble solids content. ACSO concentration and composition changed with S fertility, and the response was cultivar dependent. At S treatments that induced S deficiency symptoms during active bulbing, (+)S-methyl-L-cysteine sulfoxide was the dominant flavor precursor, and the flavor pathway was a strong sink for available S. As S fertility increased to luxuriant levels, trans(+)-S-(1-propenyl)-L-cysteine sulfoxide (PRENCSO) became the dominant ACSO. (+)S-propyl-L-cysteine sulfoxide was found in low concentration relative to total ACSO at all S fertility treatments. With low S fertility, S rapidly was metabolized and low γ-GP concentrations were detected. As S fertility increased, γ-GP increased, especially γ-L-glutamyl-S-(1-propenyl)-L-cysteine sulfoxide, the penultimate compound leading to ACSO synthesis. Nearly 95% of the total bulb S could be accounted for in the measured S compounds at low S fertility. However, at the highest S treatment, only 40 % of the total bulb S could be attributed to the ACSO and γ-GP, indicating that other S compounds were significant S reservoirs in onions. Concentrations of enzymatically produced pyruvic acid (EPY) were most closely related to PRENCSO concentrations. Understanding the dynamics of flavor accumulation in onion and other vegetable Alliums will become increasing important as the food and phytomedicinal industries move toward greater product standardization and characterization.

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Chen-Yi Hung, John R. Murray, Sarah M. Ohmann, and Cindy B.S. Tong

HPLC analyses, and Alan G. Smith for advice and the use of his lab space. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely

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Ninghang Wang, Chao Zhang, Sainan Bian, Pengjie Chang, Lingjuan Xuan, Lijie Fan, Qin Yu, Zhigao Liu, Cuihua Gu, Shouzhou Zhang, Yaling Wang, and Yamei Shen

typical species and four corresponding cultivars, were investigated to analyze their flavonoids by high-performance liquid chromatography coupled with diode array detection (HPLC-DAD) as well as HPLC with electrospray ionization and mass spectrometry (HPLC

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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

Open access

Yi Gong, Ronald B. Pegg, Adrian L. Kerrihard, Brad E. Lewis, and Richard J. Heerema

Technology (Athens), vacuum packed, and stored at −80 °C until analyzed. Extraction of phenolic compounds (as lyophilized hydrophilic extracts). Before all analyses [TPC, hydrophilic-oxygen radical absorbing capacity (H-ORAC FL ), and HPLC], a lyophilized

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Kelechi Ogbuji, Gloria S. McCutcheon, Alvin M. Simmons, Maurice E. Snook, Howard F. Harrison, and Amnon Levi

, NY) equipped with a 6-mm diameter sawtooth grinder type of tissue cutter. The solutions were filtered through 0.45-μm nylon-66 filters in preparation for HPLC analysis. High-performance liquid chromatography analysis. Extracts were analyzed once by

Open access

James C. Fulton, Francisco O. Holguin, Robert L. Steiner, and Mark E. Uchanski

) was followed for HPLC. During the first year, 6 mg of tissue per sample was extracted; the following year, 25 mg per sample was used. Samples were saponified with 1 mL of 2 N methanolic potassium hydroxide, vortexed for 30 s, and heated at 50 °C for 1

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

plants using ultraviolet-visible spectrophotometry and HPLC. This research will provide information on the presence, color, and number of pigments and polyphenols (colorants) in plant extracts for possible use as hair coloring dyes. Materials and Methods

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Yifei Wang, Stephanie K. Fong, Ajay P. Singh, Nicholi Vorsa, and Jennifer Johnson-Cicalese

V. tenellum . By using HPLC and LC-ESI-MS-MS, the objectives of the study were to investigate 1) flavonoid (anthocyanins, flavonols, and proanthocyanidins) and organic acid profiles of different blueberry species, 2) variation of flavonoid and

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Calen McKenzie, Ivette Guzman, Ciro Velasco-Cruz, and Paul W. Bosland

., 2012 ). About 1.0 g of fresh leaf tissue from each sample was ground in a mortar and pestle with 15 mL of reagent high-performance liquid chromatography (HPLC)-grade ethanol (Sigma-Aldrich, St. Louis, MO) as the extraction solvent. The ethanolic leaf