Sensory Threshold Studies of Picrocrocin, the Major Bitter Compound of Saffron.

This study is part of a wider project on the bitter taste of saffron and its preparations. A deeper knowledge on the taste perception of picrocrocin is necessary in order to develop products that satisfy consumer senses and provide them with adequate amounts of saffron major constituents, also appreciated for bioactivity. A systematic approach on the bitterness of picrocrocin, the major responsible compound, was conducted. A panel was trained specifically for the determination of taste detection and recognition thresholds of picrocrocin, which were found to be 5.34 and 7.26 mg/L, respectively, using the Ascending Forced Choice of Limits methodology. The threshold values were examined in water in absence and presence of other saffron constituents and ethanol and were found to decrease when served hot (61 ± 4 °C). Bitterness was enhanced in 40% (v/v) aqueous ethanol. In both aqueous and ethanol extracts, the presence of saffron volatiles improved bitterness perception. The usefulness of the study was tested in the case of commercial saffron based infusions.