Changes in protein composition during strawberry (Fragaria x ananassa Duch.)fruit ripening

PEDRO MARCOS CIVELLO; CHAVES AR; AÑÓN MC

JOURNAL OF FOOD BIOCHEMISTRY

Blackwell Publishing

Año: 1996 vol. 20 p. 135 - 153

0145-8884

The changes in strawberry native proteins and polypeptides during ripening were studied. The analysis of native proteins extracts by non-denaturing electrophoresis showed the presence of a protein species in the '25% Red' ripening stage or later. This species, constituted by a 40 kDa polypeptide, was hardly detected in 'Large green' and 'White' fruit extracts. The polypeptide profile, obtained with SDS-PAGE, changed during ripening. Most polypeptides were found in all ripening stages, but the distribution of some of them varied during ripening. As seen in climacteric fruits, the protein synthesis (measured by 35S-methionine labelling) in strawberry was mainly directed towards the regeneration of previously existing proteins. As the ripening proceeded, the synthesis of 67 and 63 kDa polypeptides increased, while those of 82, 56 and 25 kDa decreased. Three very-abundant polypeptides (36, 24 and 23 kDa) were located only in the achenes and were not labelled in any ripening stage.