Identification, Chemical Synthesis, and Sweetness Evaluation of Rhamnose or Xylose Containing Steviol Glycosides of Stevia (Stevia rebaudiana) Leaves

Steviol glycosides obtained from Steviarebaudiana leaves are increasingly used in the foodindustry as natural low-caloriesweeteners. Among them, the sweetness of major glycosides composedof glucose residues (e.g., stevioside and rebaudioside A) has beenwidely studied. However, the properties of minor natural productscontaining rhamnose or xylose residues are poorly investigated. Inthis study, five unreported steviol glycosides containing rhamnoseor xylose were extracted from our developing stevia leaves, and theirsweetness was evaluated. The highly glycosylated steviol glycosideswere identified, and their structures were examined by fragmentationanalysis using mass spectrometry. Chemical synthesis of these glycosidesconfirmed their structures and allowed sensory evaluation of minorsteviol glycosides. Our study revealed that a xylose-containing glycoside,rebaudioside FX1, exhibits a well-balanced sweetness, and thus, itis a promising candidate for natural sweeteners used in the food industry.

Automated summary

In this study, five unreported steviol glycosides containing rhamnose or xylose were extracted from developing stevia leaves, and their sweetness was evaluated. The structures of these glycosides were confirmed and their sensory evaluation was conducted. One xylose-containing glycoside, rebaudioside FX1, showed a well-balanced sweetness and is a promising candidate for natural sweeteners in the food industry.