Post-harvest UVC irradiation effect on anthocyanin profile of grape berries.

DE ROSAS, MARÍA INÉS; PONCE, MARÍA TERESA; GARGANTINI, RAQUEL; MARTÍNEZ, LILIANA

Mendoza

Congreso; Reunión de la Sociedad de Biología de Cuyo; 2010

Sociedad de Biología de Cuyo

Anthocyanins are a class of phenolic compounds that contribute to the color of red grapes and have shown nutraceutical properties for human health.  UVC light irradiation has been proved to increase phenolic compounds such us stilbenes, but its effect on anthocyanins has not been reported. The aim of this work was to identify the best treatment conditions of UVC light irradiation on post-harvest berries of Malbec (M), Cabernet Sauvignon (CS) and Tempranillo (T) for anthocyanin increments. Grape berries were irradiated with 240 W at 20 and 40 cm from the light source, for 30, 60 and 120 seconds. Both, irradiated and control grapes were stored on darkness at 20 °C until anthocyanin extraction with methanol/ClH. HPLC analysis were performed and nine anthocyanins were quantified. UVC light irradiation modified the anthocyanin profile of the three cultivars. All the glucoside anthocyanins derivates and peonidin-acetyl-glucoside, as well as total anthocyanins were increased when CS berries were exposed to UVC for 120 s at 40 cm. This suggests that UVC stimulated the entire biosynthetic pathway. The anthocyanin content of the control berries was always higher than the treatments with UVC on M and T, making necessary to evaluate less rigorous conditions for these varieties.