Taste Perception of Sugar-Free Isomaltooligosaccharides

The influence of structural characteristics on taste perception of glucooligosaccharides (GlcOS) remains poorly understood. This study examined the role of α-1,6 glycosidic linkages in GlcOS taste perception by evaluating two sugar-free α-1,6 linkage-containing GlcOS: maltosyl-isomaltooligosaccharides (MIMO) and isomaltooligosaccharides (IMO). Both target samples were fractionated via graded ethanol precipitation to remove mono- and disaccharides. Structural characterization confirmed average degree of polymerizations of 6 and 5 for the MIMO and IMO preparations, respectively. NMR analyses showed α-1,6 linkage proportions of ~75% in MIMO and ~50% in IMO, with the latter also containing branched maltooligosaccharides. In sensory tests, participants (N=28) were able to discriminate 150 mM samples from water (p<0.05) and described them as "slightly sweet" in the absence of lactisole, a sweet taste inhibitor. In the presence of lactisole, the samples were not detectable (p>0.05). Both samples were also detectable at 75 mM (N=25; p<0.05) with similar detectability to equimolar glucose and maltose. These results demonstrate that α-1,6 linked GlcOS elicit sweet taste and that MIMO and IMO preparations exhibit comparable detection rates.