Studies on the Stability of Carotenoids in Garland Chrysanthemum (Ipomoea spp.) as Affected by Microwave and Conventional Heating

1992 ◽  
Vol 55 (4) ◽  
pp. 296-300 ◽  
Author(s):  
B. H. CHEN

The effect of microwave and conventional heating on carotenoid stability in garland chrysanthemum was studied. Each cooking treatment was conducted for 0, 2, 4, 8, and 16 min with two replications. The various carotenoids were analyzed by high-performance liquid chromatography with photodiode-array detection. Experimental results suggested that microwave cooking could retain more β-carotene and less lutein than conventional cooking when the output power was 180 W. Epoxy-containing carotenoids were more susceptible to heat loss than other carotenoids. Both cis-lutein and cis-β-carotene contents were higher with the increase of heating time. The increase of cis-β-carotene content also implied that the provitamin A activity would decrease.

1993 ◽  
Vol 56 (1) ◽  
pp. 51-54 ◽  
Author(s):  
B. H. CHEN ◽  
J. R. CHUANG ◽  
J. H. LIN ◽  
C. P. CHIU

The provitamin A contents of 16 vegetables grown in Taiwan were analyzed by high-performance liquid chromatography with photodiode-array detection. The amounts of the major provitamin A compounds, (β-cryptoxanthin, α-carotene, and β-carotene ranged from 0–6.8, 0–27.7, and 0.6–104.9 (μg/g, respectively. The highest β-carotene content was found in basil, followed by onion fragrant, kale, carrot, spinach, water convolvulus, mustard, green onion, garland chrysanthemum, sweet potato, green pepper, yellow com, mustard stem, lettuce, cabbage, and celeriac. Carrot was the only vegetable found to contain α-carotene while com was the vegetable to contain (β-cryptoxanthin.


2017 ◽  
Vol 2 (4) ◽  
Author(s):  
Sun Hee Kim ◽  
Rita Marina Heeb ◽  
Irene Krämer

AbstractBackgroundProfound knowledge about the physicochemical stability is necessary in order to determine the “beyond-use-dates” of ready-to-administer preparations after reconstitution and dilution. This is especially true for unstable azanucleoside drugs like decitabine. The aim of this study was to determine the physicochemical stability of decitabine after reconstitution and dilution of DacogenMethodsTo determine the stability of frozen DacogenTo determine the stability of reconstituted DacogenDiluted DacogenDecitabine concentrations were determined at 0, 5, 8, 12, 24 and 48 hours after preparation. The pH-values were determined at 0, 8, 24 and 48 hours. Each sample was assayed by a validated stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) assay with photodiode array detection.ResultsWhen test solutions of reconstituted DacogenIn reconstituted test solutions in glass vials and in diluted test solutions in infusion bags stored under refrigeration decitabine concentrations remained above 90 % of the initial concentration for 12 hours and 24 hours, respectively. Several peaks of degradation products were observed which explicitly increased over time.In all test solutions the pH-values amounted to pH 7 and remained unchanged. No particulate matter and no colour changes were observed over the test period.ConclusionsReconstituted decitabine solution (Dacogen


1992 ◽  
Vol 605 (2) ◽  
pp. 221-225 ◽  
Author(s):  
Marcello Previti ◽  
Francesco Dotta ◽  
Giuseppe Mario Pontieri ◽  
Umberto Di Mario ◽  
Luisa Lenti

2001 ◽  
Vol 67 (12) ◽  
pp. 5721-5728 ◽  
Author(s):  
Alice C. L. Churchill ◽  
Larry D. Dunkle ◽  
Walter Silbert ◽  
Kevin J. Kennedy ◽  
Vlado Macko

ABSTRACT Pathogenic strains of the soilborne fungus Periconia circinata produce peritoxins with host-selective toxicity against susceptible genotypes of sorghum. The peritoxins are low-molecular-weight, hybrid molecules consisting of a peptide and a chlorinated polyketide. Culture fluids from pathogenic, toxin-producing (Tox+) and nonpathogenic, non-toxin-producing (Tox−) strains were analyzed directly by gradient high-performance liquid chromatography (HPLC) with photodiode array detection and HPLC-mass spectrometry to detect intermediates and final products of the biosynthetic pathway. This approach allowed us to compare the metabolite profiles of Tox+ and Tox− strains. Peritoxins A and B and the biologically inactive intermediates,N-3-(E-pentenyl)-glutaroyl-aspartate, circinatin, and 7-chlorocircinatin, were detected only in culture fluids of the Tox+ strains. The latter two compounds were produced consistently by Tox+ strains regardless of the amount of peritoxins produced under various culture conditions. In summary, none of the known peritoxin-related metabolites were detected in Tox− strains, which suggests that these strains may lack one or more functional genes required for peritoxin biosynthesis.


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