Chemists at the University of York, UK, have found that the shells of a variety of pistachio produce a similar taste and aroma to coffee when roasted, showing potential for a caffeine-free alternative to the drink.
When Pistachio terebihius pistachio nuts were roasted for 20 minutes at 200ȼ ͣ C they started to show a volatile chemical profile similar to that of roasted coffee beans. The aroma profile included citrus, pine or turpentine, and caramel and burnt sugar.
Six samples of pistachio were roasted in a frying pan at 200ȼ ͣ C for different periods of time ranging from 5-25 minutes, while one set was left uncooked as a control. The pistachio were then ground to fit through a 1 mm sieve and analysed for their chemical composition.
The aim was to see which volatiles are released at different stage of roasting and identify the ideal roasting time to produce the best aroma and keep undesirable products to a minimum. The results, published in the journal Food Chemistry, showed that the pistachios produced the most volatiles after 20 minutes' roasting, after which the effect decreased. Pan-roasting produced furans, furanones, benzene derivative, pyrazines and other volatiles typical of coffee aroma and flavour.
University of York chemist, Mustafa Ӧzel, said that pistachio "may provide an alternative for use in the coffee industry", Planet Earth Online reported.
"There are lots of important anti-oxidants in pistachios which are beneficial to health and they don't contain caffeine. Therefore pistachio coffee could be said to be healthier than conventional coffee," Ӧzel said.