Variation of fruit characteristics during the ripening of two Patagonian native species

M ARENA; G VATER

CHILE

Simposio; 9th International Ribes and Rubus Symposium; 2005

INTERNATION SOCIETY FOR HORTICULTURAL SCIENCE

Ribes magellanicum Poiret and Berberis buxifolia Lam are Patagonian native shrubs often growing in Nothofagus forest clearings and wood margins. Its small berries can be eaten fresh or in marmalades and jams. The objective of this work is to study some physical and chemical changes in fruits of Ribes magellanicum and Berberis buxifolia during the ripening. The fruits were harvested during the 2004-2005 growing season, from two populations situated near Ushuaia city (54° 48’ SL, 68° 19’ WL), Tierra del Fuego, Argentina. The full flower occurred early in November in both species, R. magellanicum and B. buxifolia. The weight and size of R. magellanicum fruits increased abruptly until early January (59 days from full flower), presenting the studied variables similar values until mid February (98 days from full flower); then, the weight and size decreased abruptly at 105 days from full flower, when the last fruits were harvested from the plants. The fruits attained maximum fresh and dry weight of 0.20 and 0.05 g per fruit, respectively. The fruit percentage of humidity was near 80% at the beginning of the fruiting period and fell to the half at the end of the ripening. The berries presented near 7 and 8.5 mm in transversal and longitudinal diameter as maximum, respectively. The soluble solids increased from 14 °Brix on  January 18th (70 days from full flower) to 17 °Brix a month later (98 days from full flower), while the titratable acids in juice decreased from 1.5 to 0.4 % in the same period, varying the soluble solids: titratable acids ratio from 8.5 to 42. When the anthocyanin concentration was measured, a concentration of near 10 mg/100g fruits was found in mid January (70 days from full flower). However, at the end of the ripening period the fruit anthocyanin content increased to 240 mg/100g fruits. In B. buxifolia fruits, the weight and size increased abruptly until mid January (70 days from full flower), presenting the studied variables similar values until February 10th (91 days from full flower), decreasing to the end of the ripening period in March, when the last fruits were obtained from the plants. The fruits attained maximum fresh and dry weight of 0.43 and 0.14 g per fruit, respectively. The maximum fruit percentage of humidity was of 84% at the beginning of the fruiting period and fell to less than the half at the end of the ripening. The berries presented near 9.5 and 9 mm in transversal and longitudinal diameter as maximum, respectively. The soluble solids varied from 12.8 °Brix on  January 6th (56 days from full flower) to 28-30 °Brix in mid March (126 days from full flower), while the titratable acids in juice decreased from 2.5 to 1.34 % in the same period, varying the soluble solids: titratable acids ratio from 5 to 21. Anthocyanin fruit concentration greatly varied from 160 at January 20th (70 days from full flower) to near 900 mg/100g fruits at the end of the ripening period in mid March (126 days from full flower). The studied variables presented significant changes along the ripening period and could be considered as good markers of this process. These results are the first antecedents of fruit ripening of these native species in Tierra del Fuego.