Bitter compounds are hydrophobic (Venanzi 1984). and can reside in
lipophilic environments. Therefore, reduction of fat may increase the “effective”
concentration of the bitter compounds in the aqueous phase, where they are
perceived as bitter. In our study, this likely explains why oil dilutions were less
bitter than the control, unlike the remaining tastes, where the oil dilutions were
equal in taste intensity to the control.
Food formulators must be cautious when creating reduced fat or fat-free
products. If fat is replaced with water or an aqueous ingredient mixture, the
salty, sweet, sour, and umami tastes may become diluted and thus, weakened,
while the bitter taste may become enhanced. Such a shift in taste balance may
partially explain why low-fat and fat-free foods often do not taste as good as
their full-fat versions, since people generally like the sweet, salty, sour and
umami tastes and dislike bitterness