Changes In The Sensory Perception Of 'Hass' Avocado During Fruit Maturation and Ripening

Avocado flavor improves dramatically during maturation and also changes as a result of ripening, but prior research had focused almost entirely on alterations in oil content as a means of explaining the differences in flavor.  Other factors beyond just oil content are likely involved that act to alter flavor during maturation and ripening.  The enhancement of likeability due to maturation is associated with avocados becoming creamier and less watery in texture, and richer and less grassy in flavor.  Three of the most prominent volatiles released following the homogenization of avocado flesh are hexanal, E-2-hexenal and 2,4-hexadienal.  These volatiles all have a grassy aroma, are abundantly present in immature fruit, and are the likely cause of the grassy flavor.  The grassiness is much less apparent in mature fruit that releases lesser amounts of these volatiles.  During maturation it has also been noted that acetaldehyde, methyl acetate, pentanal and β-myrcene all increase in concentration and may be involved in the enhancement of flavor.  Pentanal is especially of note as it has a nutty aroma and nuttiness is very desirable characteristic for avocado flavor.  Rates of respiration and ethylene release strongly increase in avocados during ripening as the fruit soften.  Aroma volatiles also change in concentration as a result of ripening, primarily by declining in amount.  Research has indicated that avocado flavor is governed by a multitude of factors, with aroma volatiles appearing to play a prominent role.