Cell-wall metabolism of 'Arbequina' olive fruit picked at different maturity stages
Information on cell-wall metabolism during ripening of intact fruit of olive (Olea europaea L.) is scarce, despite the impact of cell-wall properties on fruit susceptibility to mechanical damage, infestations or rots. In this work, 'Arbequina' fruit were picked and classified into five maturity groups according to external colour. Cell-wall materials were isolated from the fruit pericarp as alcohol-insoluble residue (AIR), fractionated and analysed, and a range of cell-wall-modifying enzyme activities were measured. AIR content increased sharply at stages 2 and 3, in parallel with fruit expansion. Yields of the sodium carbonate-soluble fraction, enriched in covalently bound pectins, decreased after stage 4, along with a sharp decline in the ratio of neutral sugars to uronic acids, which suggests substantial loss of neutral sugars from pectin side-chains. The activities of α-
l-arabinofuranosidase (AFase) and, to a lesser extent, β-galactosidase (β-Gal) increased simultaneously, consistent with the possible contribution of the loss of pectin-bound arabinosyl and galactosyl residues to the ripening-related softening of fruit.
Lara, I., Albrecht, R., Comabella, E., Riederer, M. and Graell, J. (2018). Cell-wall metabolism of 'Arbequina' olive fruit picked at different maturity stages. Acta Hortic. 1199, 133-138
L-arabinofuranosidase, cell wall, fruit, olive, ripening