How drying temperature and rate of weight loss can affect the biosynthesis of nutritional compounds
Fabio Mencarelli, Bellincontro Andra, antelmi Giorgia and Isabella Nicoletti
Abstracts Book, 6th International Postharvest symposium, 8-12 April 2009, Antalya, Turkey. 256 pages.
2009
บทคัดย่อ
Aleatico grape bunches coming from plant irrigated and not irrigated were subjected to partial postharvest dehydration at 10, 20 or 30°C, 45% RH, and 1.5 m/secair flow, until 40% of mass loss. Rate of mass loss was slightly higher (3-4%) in not irrigated sample at 10°C while the inverse was at 30°C, even though the difference was not significant. Sugars increased at 29, 31, and 6% respectively at 10, 20, and 30°C but significant difference was observed only at 20°C where irrigated samples had about 3% higher RI value. Total anthocyanins increate until 20% or 30% of mass loss at 20°Crespectively in not irrigated and irrigated pies and then declined. At 10 and 30°C, anthocyanins decreased. Malvidin-3-glucoside was the anthocyanin more esponsabile for these changes. Catechin increased 4-folds in irrigated sample dehydrated at 20°C at 10% of mass loss and then declined. In not irrigated sample the increase was less. At 10 and 30°C no increase was observed. Trans-resveratrol had the same behaviour as catechin. Quercetin-3-0-glucoside increased at 20% of mass loss in not irrigated sample and at 30% of mass loss in irrigated one. Kempferol-3-0-glucoside showed the same behaviour of quercetin. At 10 and 30°C no increase were observed. It appears that irrigation can affect the water stress response during the postharvest dehydration but 20°C temperature of dehydration is the best temperature to increase significantly the content of functional compounds with partial rape dehydration (20-30%).