Evaluación de los atributos fisicoquímicos de uvas bronze "granny val" muscadinas durante la maduración

Abstract

A study was conducted to assess quantitative changes in physical characteristics and chemical constituents during ripening of 'Granny Val' grapes picked at three stages of maturity: green, table, and ripe. The studied variables were: soluble solids (SS), titratable acidity (AT), SS/AT, sugars (glucose, sucrose and fructose), phenols, color and firmness. Most of the physical and chemical parameters evaluated increased: soluble solids SS (9.50 to12.80), Ratio SS/TA (2.06 to 5.17), pH (3.14 to 3.44) and phenolic compounds (25.23 to 31.96) while titratable acidity (AT) declined by 47% (4.64 to 2.48). Compression force (firmness) decreased by 48% and penetration force also did by 14%, Hunter L* (brightness), and b* decreased, while Hunter a* increased. The grapes became less green (more yellow) and bronze in color. Firmness of the fruit was reduced in 48% and of the peel in 14% while ripening. However, they kept good qualities with the ripeness process which allow them to resist during storage and transportation.