Pezzotti Giuseppe, Zhu Wenliang, Aoki Takashi, Miyamoto Akihiro, Fujita Isao, Nakagawa Manabu, Kobayashi Takuya
Ceramic Physics Laboratory, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, Kyoto 606-8585, Japan.
Department of Molecular Genetics, Institute of Biomedical Science, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka 573-1010, Japan.
Foods. 2024 Sep 26;13(19):3068. doi: 10.3390/foods13193068.
Besides all sharing an extraordinary high (i.e., up to ~450 times) sweetening power as compared to sucrose and while presenting strong similarities in their molecular structures, molecules belonging to the family of diterpene glycosides (i.e., the secondary metabolites of ) differ in specific structural details that strongly impact on their levels of sweetness and bitter aftertaste. Given the nutritional and pharmacological benefits of steviol secondary metabolites as natural dietetic and anti-diabetic remedies, extraction and purification of steviol glycosides from plant material are nowadays widely spread among many countries. However, an unpleasant bitter aftertaste, which is linked to a genetic variation in human bitter taste receptors, hampers the full exploitation of such benefits and calls for a prompt improvement in organoleptic property control of stevia products. A deeper understanding of the molecular structure of different steviol glycosides and the consequent development of promptly measurable criteria for the organoleptic performance of their mixtures will support processing optimization and control of taste profiles within desired yields. The present research aimed at establishing Raman spectroscopic algorithms for quantitative characterizations of raw stevia-based sweetener products. First, a series of twelve high-purity diterpene glycosides were analyzed by high spectrally resolved Raman spectroscopy and their spectra analyzed in order to establish a complete Raman library of molecular structures. Then, quantitative spectroscopic parameters were built up and applied to characterize the organoleptic property of five different commercially available samples including the recently developed Rebaudioside M isoform. Raman spectroscopy was confirmed as a versatile analytical technique that could be used for quantitative quality control tasks on the production line and for prompt in situ characterizations of purchased products.
与蔗糖相比，所有二萜糖苷类分子都具有极高的（即高达约450倍）甜味，并且在分子结构上有很强的相似性，但它们在特定结构细节上存在差异，这些差异对其甜度和苦味后味水平有很大影响。鉴于甜菊醇次生代谢产物作为天然饮食和抗糖尿病药物具有营养和药理益处，如今从植物材料中提取和纯化甜菊糖苷在许多国家广泛开展。然而，与人类苦味受体的基因变异有关的不愉快苦味后味，阻碍了这些益处的充分利用，需要迅速改善甜菊产品的感官特性控制。深入了解不同甜菊糖苷的分子结构，并由此开发出其混合物感官性能的快速可测量标准，将有助于在所需产量范围内优化加工和控制口味特征。本研究旨在建立拉曼光谱算法，用于对基于甜叶菊的生甜味剂产品进行定量表征。首先，通过高光谱分辨拉曼光谱对一系列十二种高纯度二萜糖苷进行分析，并对其光谱进行分析，以建立一个完整的分子结构拉曼库。然后，建立定量光谱参数并应用于表征包括最近开发的莱鲍迪苷M异构体在内的五种不同市售样品的感官特性。拉曼光谱被确认为一种通用的分析技术，可用于生产线上的定量质量控制任务以及对购买产品的快速原位表征。
