COMPARATIVE ANALYSIS OF HEAT-TREATED ORANGE FRUITS DURING DIFFERENT POST-HARVEST STORAGE CONDITIONS

PEROTTI, V.E.; DEL VECCHIO, H.; PODESTÁ, F.E.

Tucumán

Congreso; XLV Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2009

SAIB

Heat treatment or curing is a common procedure prior to long time storage of citrus fruits. The aim of this study was to characterize changes at the molecular level induced by heat treatment on the proteome of orange fruit (Citrus sinensis L. Osbeck). Following two-dimensional PAGE, more than 50 differential protein spots were detected in juice vesicle tissue among all comparisons made. Heat treatment significantly affected the abundances of 16 proteins, while 25 differential proteins were found along the storage period. Identification of these citrus proteins by mass spectrometry and annotation according to the NCBI and Viridiplantae ESTs data bases revealed that 27% were stress-related proteins involved in cell rescue, defense and virulence, 24% were involved in metabolism, 20% were found to be storage proteins, and 15% belonged to the biogenesis of cellular components; being the rest related to minor categories. In order to analyse the changes produced by curing in the flavedo, different antioxidant enzyme activities were performed on this tissue. SOD and POD activities increased, APX activity decreased, whereas CAT and GR showed no significant differences. Furthermore, a marked putrescine induction was observed in cured flavedo. Overall, the present study provides the first analysis at the molecular level of citrus fruit responses to heat treatment