USDA researcher discusses Hass sensory perception

U.S. Department of Agriculture researcher David Obenland told a January 13 session of the January 12-16 International Conference on the Status of Plant and Animal Genome Research in San Diego how genetic traits affect sensory perception in Hass avocados.

Obenland was the presenting author of “Changes In The Sensory Perception of Hass Avocado During Fruit Maturation and Ripening” during the conference’s avocado genome session. Research was also performed by Sue Collin and Jim Sievert of the University of California agricultural research and extension center in Parlier and by Fayek Negm and Mary Lu Arpaia of the University of California, Riverside. Funding for Obenland’s research was provided by the California Avocado Commission and by Pinkerton Growers of California. Obenland is out of the USDA’s Parlier research station.

The work focuses on flavor development. “Immature avocados have a really greasy taste,” Obenland said. “They are not as good to eat.”

The initial work focused on oil content while later research involved dry matter, which was easier to quantify. “We were looking primarily at textural aspects,” Obenland said.

The research involved a public panel which confirmed that firm and watery characteristics were negatively perceived while smooth and creamy textures were positive for avocado consumers. Aroma traits were also included in the research.

Obenland harvested fruit throughout the season and analyzed samples. “As the fruit matured the greasiness declined to almost nothing,” he said.

Some of the organic compounds affecting smell and taste traits decreased in concentration while chemicals creating more positive effects increased during the maturation process. “Avocados have to be ripened before we eat them,” Obenland said.

Hexanal is a descriptor of greasiness. “There was a very large decline,” Obenland said.

The role of some of the compounds is currently unknown. “Now we’re trying to figure out what’s going into those attributes,” Obenland said.