2.6. Sensory evaluation
Sensory evaluation (consumer analysis) was carried out by a 51
member untrained panel (20 males and 31 females) consisting of
faculty and graduate students of the Laboratory of Food Chemistry and
Technology of the University of Ioannina Department of Chemistry.
Panelists were chosen using the following criteria: ages between 22
and 60, non-smokers, without reported cases of food allergies who
consume chocolate products regularly. Approximately 20 g of dark
chocolate with hazelnuts was placed in small plastic containers coded
with 3-digit random numbers and tightly capped. The samples were
allowed to stand for 0.5 h prior to the evaluation to allow equilibration
of volatiles in the headspace. Panelists were served a set of 5 treated
samples along with a control sample (stored in glass jars at −18 °C);
they were instructed to consume the whole sample and rinse their
mouth with sparkling water (room temperature), in between sample
evaluation. Sensory attributes evaluated included color, texture, odor
and taste. Scoring was carried out on paper ballots using a 9 point
hedonic scale where: 9=extremely like and 1=extremely dislike
for the evaluation of odor, and taste as well as 9=very crispy and