CHARACTERIZATION OF GRAPEFRUIT (CITRUS PARADISE) FRUITS PRODUCED IN ARGENTINA AND PARAGUAY

Grapefruit (Citrus paradise) is an important source of bioactive compounds, largely due to the presence of flavonoids (naringin, rutin, narigenin, hesperidin and hesperedine), as well as ascorbic acid, and carotenoids. The naringin is the main flavonoid in grapefruit and is used as a marker of juices. The studies were done on fruits of grapefruit ‘Paranᒠgrafted on ‘Troyer’ (TC),‘Carrizo’ citranges (CC) and ‘Swingle’ citrumelo (SC), and ‘Duncan’ grafted on ‘Duncan’. The grapefruits were from plots located in Bella Vista, Corrientes, Argentina (28,5°S 59,3°W), and Fram, Paraguay (27,0°S 55,9°W). Values of pH were in the range of 3,4 to 4,2; acidity titrable higher than 10.4 g/L; total sugars between 70.3 and 85.9 mg glu/ml and ash between 0.28 and 0.99%. Naringin levels rose from 17.6 to 76.1 mg/L, neohesperidin from 10.5 to 1.9 mg/L for ‘Paranᒠand ‘Duncan’ respectively. Hesperidin was not detected in ‘Duncan’ and ‘ParanᒠCC and only trace amounts were determined in the other fruits. ‘Duncan’ had more than four times the naringin content and lower neohesperidin and sucrose content than ‘Paranᒠfruits. No significant differences were found between other parameters analyzed.