Relative sweetness and sweetness quality of phyllodulcin [(3R)-8-Hydroxy-3-(3-hydroxy-4-methoxyphenyl)-3,4-dihydro-1H-isochromen-1-one]

A review on natural sweeteners, sweet taste modulators and bitter masking compounds: structure-activity strategies for the discovery of novel taste molecules

Growing demand for the tasty and healthy food has driven the development of low-calorie sweeteners, sweet taste modulators, and bitter masking compounds originated from natural sources. With the discovery of human taste receptors, increasing numbers of sweet taste modulators have been identified through human taste response and molecular docking techniques. However, the discovery of novel taste-active molecules in nature can be accelerated by using advanced spectrometry technologies based on structure-activity relationships (SARs). SARs explain why structurally similar compounds can elicit similar taste qualities. Given the characterization of structural information from reported data, strategies employing SAR techniques to find structurally similar compounds become an innovative approach to expand knowledge of sweeteners. This review aims to summarize the structural patterns of known natural non-nutritive sweeteners, sweet taste enhancers, and bitter masking compounds. Innovative SAR-based approaches to explore sweetener derivatives are also discussed. Most sweet-tasting flavonoids belong to either the flavanonols or the dihydrochalcones and known bitter masking molecules are flavanones. Based on SAR findings that structural similarities are related to the sensory properties, innovative methodologies described in this paper can be applied to screen and discover the derivatives of taste-active compounds or potential taste modulators.

Fractionation, identification and umami characteristics of flavor peptides in natural brewed soy sauce

To investigate the umami mechanisms and characteristics of soy sauce flavor peptides, four fractions from natural brewed soy sauce were separated using ultrafiltration and Sephadex G-15 gel filtration chromatography. Sensory and ligand-receptor interaction tests showed that the umami strengths of the fractions were related as follows: U1 > U2, G3 > G2, and G3 > U1. Peptide identification revealed that the < 550-Da peptides might be the major contributors to the umami taste of U1 and G3. The higher umami strength of G3 might be attributable to its higher content of umami peptides. G3's concentration-relative umami intensity curve was plotted using a two-alternative forced choice test. It was also revealed that less sourness, higher saltiness and cool (4 ℃) and hot (50 ℃) serving conditions were conductive to the umami perception of G3. The results could provide a reference for the application of soy-sauce flavor peptides in food.

Comprehensive Metabolite Profiling of Hydrangea macrophylla ssp. serrata Extracts Using Liquid Chromatography Coupled with Electrospray Ionization Ion Mobility Quadrupole Time-of-Flight Mass Spectrometry

A wide range of secondary metabolites has been described for various Hydrangea species, including the sweet-tasting phenyldihydroisocoumarin phyllodulcin, which is found in the leaves of Hydrangea macrophylla ssp. serrata. This work aims at the development and validation of an analytical workflow for comprehensive semi-polar metabolite profiling using liquid chromatography coupled with electrospray ionization ion mobility quadrupole time-of-flight mass spectrometry (UPLC-ESI-IMS-QToF-MS) to complement existing analytical studies. The unsupervised analysis of this data set demonstrates the capability of this analytical workflow to distinguish different H. macrophylla ssp. serrata cultivars. In combination with supervised analysis, a list of metabolites responsible for the differentiation of the cultivars studied has been obtained. Suspect screening of phenyldihydroisocoumarins provides comprehensive information, which could help in the search for key enzymes related to the biosynthesis of phyllodulcin.

Separation of Dihydro-Isocoumarins and Dihydro-Stilbenoids from Hydrangea macrophylla ssp. serrata by Use of Counter-Current Chromatography

Previously, different Hydrangea macrophylla ssp. serrata cultivars were investigated by untargeted LC-MS analysis. From this, a list of tentatively identified and unknown compounds that differ significantly between these cultivars was obtained. Due to the lack of reference compounds, especially for dihydro-isocoumarins, we aimed to isolate and structurally characterise these compounds from the cultivar 'Yae-no-amacha' using NMR and LC-MS methods. For purification and isolation, counter-current chromatography was used in combination with reversed-phase preparative HPLC as an orthogonal and enhanced purification workflow. Thirteen dihydro-isocoumarins in combination with other metabolites could be isolated and structurally identified. Particularly interesting was the clarification of dihydrostilbenoid glycosides, which were described for the first time in H. macrophylla ssp. serrata. These results will help us in further studies on the biological interpretation of our data.

Exploring the relationships between perceived umami intensity, umami components and electronic tongue responses in food matrices

Umami intensity promotes food flavor blending and food choice, while a universal quantification procedure is still lacking. To evaluate perceived umami intensity (PUI) in seven categories of foods, modified two-alternative forced choice (2-AFC) method with monosodium glutamate as reference was applied. Meanwhile, we explored whether equivalent umami concentration (EUC) by chemical analysis and electronic tongue (E-tongue) are applicable in PUI quantification. The results indicated that EUC was appropriate in quantifying PUI of samples from meat, dairy, vegetable and mushroom groups (r = 1.00, p < 0.05). Moreover, models with a good prediction capacity for PUI and EUC (R² > 0.99) were established in separated food categories by back propagation neural networks, where E-tongue data were set as input. This study explored the effectiveness of the three methods in evaluating the PUIs of various foods, which provides multiple choices for the food industry.

Sweetness profiles of glycosylated rebaudioside A and its binary mixtures with allulose and maltitol

Rebaudioside A is a promising natural alternative sweetener but they produce increased bitterness, astringency, and unpleasant aftertastes. Glycosylation and blending with different sweeteners are known to improve the sensory characteristics of rebaudioside A. The present study was conducted to identify the relative sweetness and sensory profile of glycosyl rebaudioside A (g-reb A). The relative sweetness of g-reb A compared to 5% sucrose was determined using the two-alternative forced choice method. The sensory profiles of g-reb A and its mixtures with allulose and maltitol (1:1 ratio) were compared to those of rebaudioside A, rebaudioside D, rebaudioside M, sucralose, allulose, maltitol, and sucrose using descriptive analysis conducted by eight trained panelists. The relative sweetness of g-reb A was 155, which was lower than that of rebaudioside A. In addition, the bitter taste and aftertaste, astringency, and sweet onset of g-reb A were decreased compared to those of rebaudioside A.

Can "Functional Sweetener" Context Increase Liking for Cookies Formulated with Alternative Sweeteners?

Various strategies for replacing sugar with naturally derived sweeteners are being developed and tested. In this study, the effect of the “functional sweetener” context, which is created by providing health-promoting information, on liking for the sweeteners was investigated using a cookie model system. Cookie samples were prepared by replacing the sugar of 100% sucrose cookies (control) with phyllodulcin, rebaudioside A, xylobiose and sucralose either entirely or partly. The sensory profile of the samples was obtained using descriptive evaluations. Hedonic responses to cookie samples were collected from 96 consumers under blind and informed conditions. Replacement of 100% sucrose with rebaudioside A or phyllodulcin significantly increased bitterness but replacement of 50% sugar elicited sensory characteristics similar to those of the control. Although the “functional sweetener” context did not influence overall liking, liking for the samples was more clearly distinguished when information was provided. Consumers were segmented into three clusters according to their shift in liking in the informed condition: when information was presented, some consumers decreased their liking for sucralose cookies, while other consumers increased or decreased their liking for sucrose cookies. Results suggest that the influence of information varies among individual consumers and that cognitive stimulation, such as health-promoting information, affects liking.