کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6404868 | 1628534 | 2013 | 7 صفحه PDF | دانلود رایگان |
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 â80 °C.
⺠Total vitamin C (l-AA plus DHAA) can be determined by UHPLC-PDA. ⺠Iodometric titration only evaluates l-AA. ⺠Time between picking and consuming is crucial for vitamin C degradation. ⺠l-AA loss depends directly on pulp pH at to pH 5. ⺠Vitamin C is stable for long time periods on horticultural extracts stored at â80 °C.
Journal: LWT - Food Science and Technology - Volume 50, Issue 2, March 2013, Pages 489-495