Optimization of methodology to analyze ascorbic and dehydroascorbic acid in vegetables

Abstract

OptimizatiOn Of methOdOlOgy tO analyze ascOrbic and dehydrOascOrbic acid in vegetables flávia milagres campos*, sônia machado rocha ribeiro, ceres m. della lucia e helena maria pinheiro-sant'ana Departamento de Nutrição e Saúde, Universidade Federal de Viçosa, Av. PH Rolfs, s/n, 36571-000 Viçosa -MG, Brasil paulo césar stringheta Departamento de Tecnologia de Alimentos, Universidade Federal de Viçosa, Av. PH Rolfs, s/n, 36571-000 Viçosa -MG, BrasilRecebido em 10/1/08; aceito em 18/8/08; publicado na web em 15/12/08In this study, different solutions to extract vitamin C were tested. High-performance liquid chromatography was chosen and the conditions were based on isocratic elution in reverse phase column. Dehydroascorbic acid was determined indirectly after its reduction using dithiothreitol. The use of metaphosphoric acid to stabilize the vitamin C was shown to be required and it was necessary to neutralize the pH of the extract to apply dithiothreitol. The average recovery was 90% in collard and tomato samples. The presence of oil did not interfere in extraction and the methodology can be used to analyze stir fried vegetables.

Murici, fruit from the Cerrado of Minas Gerais, Brazil: physical and physicochemical characteristics, and occurrence and concentration of carotenoids and vitamins

“…The extraction and analysis of ascorbic acid and conversion of dehydroascorbic acid into ascorbic acid were performed according to the conditions proposed by Campos et al [13].…”

“…The analyses were performed using the same HPLC system employed in the analysis of carotenoids and the following chromatographic conditions were used: HPLC-DAD system, RP-18 chromatography column (Lichrospher 100, 250 mm × 4 mm, 5 mm), mobile phase consisting of ultrapure water with 1 mM NaH 2 PO 4 , 1 mM EDTA and pH adjusted to 3.0 with H 3 PO 4 , and mobile phase flow of 1.0 mL·min -1 . Chromatograms were obtained at 250 nm [13].…”

An improved and fast UHPLC-PDA methodology for determination of L-ascorbic and dehydroascorbic acids in fruits and vegetables. Evaluation of degradation rate during storage

“…Determination of total vitamin C was performed as proposed by Campos [21]: Tris buffer containing DTT was added to the extracts to obtain a final concentration of 20 mM DTT. The mixture was kept protected from light at room temperature for 30 min in order to convert any DHAA to L-AA.…”

Nitrogen‐protected microwave‐assisted extraction of ascorbic acid from fruit and vegetables

“…On the other hand, AA is more stable in weak acid solutions [32]. Taking into account the polarity, solubility, and stability of AA, aqueous solutions containing different kinds of weak acids were chosen for investigation, including 1 mM of hydrochloric acid, 1% of glacial acetic acid and MPA (0.0025, 0.025, 0.25 and 0.5%) [37]. Guava sample was extracted with chosen solvent under an irradiation time of 10 min, a ratio of solid/liquid of 1:10 and a microwave power of 400 W. The results are depicted in Fig.…”