Chemical characterization of two California-grown avocado varieties (Persea americana Mill.) over the harvest season with an emphasis on sensory-directed flavor analysis

Authors: Hausch, Bethany; ARPAIA, MARY LU - University Of California; KAWAGOE, ZACHARY - University Of California; Walse, Spencer; Obenland, David - Dave

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2020
Publication Date: 12/14/2020
Citation: Hausch, B.J., Arpaia, M., Kawagoe, Z., Walse, S.S., Obenland, D.M. 2020. Chemical characterization of two California-grown avocado varieties (Persea americana Mill.) over the harvest season with an emphasis on sensory-directed flavor analysis. Journal of Agricultural and Food Chemistry. 68(51):15301-15310. https://doi.org/10.1021/acs.jafc.0c05917.
DOI: https://doi.org/10.1021/acs.jafc.0c05917

Interpretive Summary: Avocados are a popular fruit but the factors in the fruit that determine how well they taste are not well known. Two varieties of avocados were sampled in an orchard throughout the season and components that could potentially be important to flavor were determined as the fruit matured. Various aroma compounds were identified in the flesh of the fruit that could impact flavor, the most important having a mushroom aroma, while others having an aroma like cut grass were also noteworthy. Most of the compounds with an active aroma were derived from fatty acids present in avocado oil. This information on some key aspects of avocado flavor should help in providing better tasting avocados to consumers.

Technical Abstract: The objective of this research was to characterize the aroma-active volatiles of avocado and use information about the avocado’s overall composition, such as lipid profile, to inform the volatiles likely origins. To achieve this end, two varieties of avocado, ‘Hass’ and ‘Gem’, were evaluated over the growing season for dry weight, moisture content by freeze drying, oil content by Soxhlet, fatty acid composition and aroma profile. Solvent-assisted flavor evaporation (SAFE) and aroma extract dilution analysis (AEDA) was performed on aroma extracts. Oleic acid was the prominent fatty acid in the oil of both varieties, at well over 50%. The majority of the aroma active compounds in avocado are lipid-derived. The most notable compounds are 1-octen-3-one (mushroom) with a flavor dilution factor as high as 8192, hexanal (grassy), (Z)-4-decenal, an unknown and (E,E)-2,4-nonadienal. Over the mid to late harvest season, a decline was observed in hexanal and an increase in octanal.