Effect of dehydration by sun or by oven on volatiles and aroma compounds of trachanas
Journal
Dairy Science and Technology
Date Issued
September 2010
DOI
10.1051/dst/2010027
Abstract
Trachanas is one of the most important traditional food products of Cyprus. It is made from fermented sheep or goat's milk or a mixture of both. The fermented milk is heated and crushed wheat is added to produce a porridge mixture. The mixture is then dried and stored in the form of "biscuits". Dehydration is performed either by sun, at a domestic level, or industrially using an oven. The objective of this study was to detect differences in aroma compounds of sun-dried or oven-dried Trachanas samples. Six samples (three sun-dried batches and three oven-dried batches) were prepared to make a porridge mixture according to the Cypriot tradition. Dried Trachanas samples were chemically analysed by the electronic nose SMart Nose system, by gas chromatography-mass spectrometry (GC/MS) and by gas chromatography-mass spectrometry- olfactometry (GC/MS/O). Triangle tests were also performed by a panel of 30 people from the CoRFiLaC staff in Ragusa, Italy. Principal component analysis applied to SMart Nose results showed a good separation between sun and oven-dried samples: Sun-dried samples showed a higher variability explained by the traditional process, in comparison to the oven-dried samples. GC/MS and GC/MS/O analysis showed higher numbers of compounds for the sun-dried Trachanas samples. In particular, double the number of odour active compounds were detected by GC/MS/O in the sun-dried samples, revealing that the use of the oven in the dehydration process generally resulted in a lower intensity of aroma. Triangle test confirmed instrumental results and clearly indicated detectable differences by consumers between sun- and oven-dried Trachanas