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Effect of time and temperature on vitamin C stability in horticultural extracts. UHPLC-PDA vs iodometric titration as analytical methods
- Spínola, Vítor, Mendes, Berta, Câmara, José S., Castilho, Paula C.
- Lebensmittel-Wissenschaft + [i.e. und] Technologie 2013 v.50 no.2 pp. 489-495
- ascorbic acid, cherimoyas, dehydroascorbic acid, foods, fruits, high performance liquid chromatography, horticulture, papayas, passion fruits, sweet peppers, temperature, titration, Portugal
- Several fruits and vegetables from Madeira Island (Portugal) were evaluated by two analytical methods for their total vitamin C content (l-ascorbic acid, l-AA and dehydroascorbic acid, DHAA). DHAA was determined indirectly with DL-1,4-dithiotreitol (DTT) applied as a pre-column reductant. Ultra high performance liquid chromatography coupled to photodiode array (UHPLC-PDA) determinations were compared with l-AA content obtained by a classic iodometric titration method. The stability of vitamin C in horticultural extracts stored at different temperatures was also investigated. Red peppers represented the better source of vitamin C followed by green peppers and papayas. Passion fruits and cherimoyas were the analyzed foodstuffs with lowest vitamin C content. Both analytical methods were suitable for l-AA analysis in various food commodities, the UHPLC-PDA technique being preferred due to its advantages of selectivity, speed and accuracy. The degradation study showed that horticultural extracts were stable at least 24 h at 4 °C and during 4 weeks when stored at −80 °C.