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Notas:
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The production of aroma volatile compounds and standard quality attributes, in addition to lipoxygenase (LOX), hydroperoxide lyase (HPL),
pyruvate decarboxylase (PDC), alcohol dehydrogenase (ADH) and alcohol o-acyltransferase (AAT) activities, were assessed during maturation of
‘Pink Lady®’ apples. Low production of aroma volatiles was observed in early harvested fruit, which gradually increased as ripeness approached.
Hexyl acetate, hexyl 2-methylbutanoate, hexyl hexanoate, hexyl butanoate, 2-methylbutyl acetate and butyl acetate were prominent within the blend
of volatiles produced by fruit throughout maturation. Multivariate analysis showed these compounds had the highest influence on differentiation
of maturity stages, indicating that aroma volatile emission is an important factor for definition of fruit ripeness, which suggests production of
these esters might be useful as an index of maturity. No large variations in AAT activity were found throughout the experimental period despite
increasing ester emission, suggesting the enhancement of ester production by ‘Pink Lady®’ apples at ripening arises mainly from greater availability
of substrates. Increased LOX activity was observed at later stages of fruit development, and the possible role of this enzyme activity on enhanced
capacity for aroma volatile biosynthesis in more mature fruit is discussed.
C. Villatoro is the recipient of a PhD grant from Agencia de Gestió d’Ajuts Universitaris i de Recerca (AGAUR). This work was supported through project AGL2003-02114, financed by Ministerio de Ciencia y Tecnología (MCyT). |
