Bitterness reduction of naringin and limonin by .BETA.-cyclodextrin.

Abstract

Taste interactions of β-cyclodextrin with naringin or limonin, which are bitter tasting constituents of citrus fruits and their products, were evaluated by psychophysical methods. The mechanism of interaction of β-cyclodextrin with naringin or limonin was explained by both the solubilities of the bitter tasting compounds and the changes brought about by proton shifts within the β-cyclodextrin.In the presence of 0.5% β-cyclodextrin, the bitterness of naringin or limonin was reduced to approximately half of what it was without β-cyclodextrin. This reduction in bitterness by β-cyclodextrin was also observed in the citrus juice itself.The solubilities of naringin or limonin increased with the addition of β-cyclodextrin. In a series of 1H NMR spectra of β-cyclodextrin in D2O, the low-field triplet signals assigned to the H-3 and H-5 protons, which are located within the cavity of β-cyclodextrin, showed a gradual shift to the higher-field values with increases in the molar ratio of naringin to β-cyclodextrin. I...