The study published in the Journal of Agricultural and Food Chemistry earlier this year said jackfruit seeds could help ease potential cocoa shortages.
The research was conducted by Fernanda Papa Spada et al. from the University of São Paulo, the Technology College of Piracicaba, the Methodist University of Piracicaba and the University of Reading.
Jackfruit is a large tropical fruit native to Southern India. It is found today in South America, Africa, Asia and Australia. Its seeds account for 15-18% of its total weight. Jackfruit is the national fruit of Bangladesh.
‘Similar to that of chocolate’
“For the first time, we found that after roasting, jackfruit seeds imparted an aroma similar to that of chocolate,” wrote the researchers.
They said the finding could help manufacturers meet demand for chocolate flavor should cocoa demand outstrip supply, adding the seeds could be an alternative revenue stream for Brazilian farmers.
“As with cocoa, the postharvest pretreatments and roasting of the jackfruit seeds are likely to influence the formation of these compounds and the quality of the aroma,” they wrote.
Postharvest processing similar to cocoa
To study the effects of postharvest treatment, the researchers developed 27 roasted jackfruit seed flours under different conditions similar to cocoa processing.
Each batch of seeds was either simply dried (dried jackfruit seeds), fermented and dried (fermented jackfruit seeds) or acidified (acidified jackfruit seeds).
The seeds were then tested under different roasting lengths and temperatures.
The researchers used 25 jackfruit collected from a single tree in the countryside of São Paulo, Brazil, between October 2013 and January 2014.
Fermented seeds with moderate roasting give best results
An untrained sensory panel of 162 people aged 18 to 54 evaluated the flours.
The researchers found the most sensory chocolate aroma in fermented flour (rather than acidified or only dried) subjected to moderate roasting conditions.
Box fermentation lasted 12 days, longer than cocoa fermentation (5 to 8 days) as jackfruit seeds are bigger than cocoa beans.
“Unfermented cocoa is very bitter and astringent with little apparent chocolate flavor, whereas the unfermented jackfruit flour (from dried jackfruit seeds) still had some chocolate aroma,” wrote the researchers.
Acidified jackfruit seeds had some chocolate aroma, but led to some negative descriptions from the sensory panel, such as ‘earthy’ and ‘rancid’.
Impact on color
The study team said jackfruit seeds had moisture, pH and color similar to cocoa.
They said seeds produced under the highest-temperature roast had a similar color or luminosity closest to cocoa powder.
However, manufacturers may need to modify color with other ingredients depending on the application, they said.
The study was funded by the National Council of Technological and Scientific and Research Foundation (FAPESP).
Journal of Agricultural and Food Chemistry
‘Optimization of Postharvest Conditions To Produce Chocolate Aroma from Jackfruit Seeds’
Authors: Fernanda Papa Spada, Lais Masson Zerbeto, Gabriel Bernardes Cabreira Ragazi, Érika Maria Roel Gutierrez, Miriam Coelho Souza, Jane K. Parker, and Solange Guidolin Canniatti-Brazaca