Pistachios could be a healthier coffee bean alternative, says study
The characteristic smell and flavour of coffee beans is only triggered after roasting, due to the release of organic compounds that exist as vapours, known as volatiles.
The study, published in Food Chemistry, aimed to find out which volatiles are released at various stages of roasting and the ideal roasting time to produce the best aroma.
At the same time scientists aimed to keep undesirable products to a minimum.
The results showed that pistachios produce the most volatiles after 20 minutes of roasting, after that the effect decreases, said the University of York researchers.
The scientists said the type of pistachio used in the study is from the Pistacia terebinthus, a fruit growing wild in Turkey.
This strain of pistachio could be a healthier alternative to the coffee bean, with antioxidant, anti-inflammatory and antiseptic properties, they said.
Methodology and results
The research team took six handfuls of pistachios and roasted them on a frying pan at 200 °C for different periods of time, from five to 25 minutes.
One set of pistachios was left uncooked as a control.
The scientists then grounded the beans to fit through a 1mm sieve and analysed the samples' chemical composition.
The type and the number of constituents characterised were observed to change with differing roasting times.
The pan-roast produced 20 new compounds of furans, furanones, benzene derivatives, pyrazines and other volatiles that are typical of coffee aroma and flavour, said the scientists.
The number of total volatile compounds increased time up to a roasting time of 20 min, then decreased slightly at 25 min.
None of the substances were detected in the fresh fruits.
The researchers said had not yet been any other studies analysing the volatiles of the roasted fruits of P terebinthus, or any detailed studies of the hull and the seed of the fruits.
Analysis of roasted and unroasted Pistacia terebinthus volatiles using direct thermal desorption-GCxGC–TOF/MS
Source: Food Chemistry
Authors: F. Gogus, M.Z. Ozel, D. Kocak, J.F. Hamilton and A.C. Lewis
Available online: doi: 10.1016/j.foodchem.2011.05.003
