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To assist increasing annual acreage of Texas-grown (U.S.A.) strawberries, it is essential to select cultivars with excellent plant and fruit quality characteristics suitable to the diverse environments. This study assessed multiple traits of 10 strawberry cultivars grown under high tunnels. A significant difference (p ≤ 0.05) was observed for all traits, which possessed a wide variability of metabolites. Plant analysis (number of live plants, plant vigor, and harvest yield) indicated that the yield ranged from 226 to 431 g/plant, positively correlated to plant vigor. Fruit physicochemical characteristic analysis, including red color (absorbance at 500 nm) and taste-associated indicators [°Brix, titratable acidity (TA), and total soluble solids (TSS)/TA], showed that °Brix and TSS/TA ranged from 8.0 to 12.9 and from 9.1 to 15.3, respectively. More than 300 volatiles were identified using solid-phase microextraction-gas chromatography-mass spectrometry, and total volatiles varied 1.5 times with high variance of individual compounds between cultivars. Descriptive sensory analysis indicated that strawberry flavor was positively associated with sensory attributes of sweetness, jammy, fruity, buttery, fresh, and creamy while negatively related to bitterness, astringency, and sourness. Partial least squares regression indicated that strawberry flavor was highly correlated with sweet taste and volatile composition. No specific relationship between these traits and day-neutral or June-bearing varieties was identified. Ideal cultivars for Texas growing conditions with superior and balanced flavor qualities were Albion, Sweet Charlie, Camarosa, Camino Real, and Chandler.

Artificial sweeteners (ASs) have generally been applied as food additives to improve the taste of sweetness. Thus, their potential toxic effects have received extensive attention. Saccharin (SAC), discovered more than a century ago, has been used as the first noncaloric AS in foods and beverages for over 100 years. Although the toxicological effects such as carcinogenicity of SAC have been controversial for a long time, there is a paucity of knowledge covering its potential behavioral toxicity and neurotoxicity. Methodologically, in current research, adult zebrafish neurobehavioral phenotypic screening approaches were introduced to systematically delineate the potential behavioral and neural toxicity of SAC by phenotyping the comprehensive neuro-behavioral profiles of adult zebrafish, which were chronically (2 months) subject to SAC (0, 1, 10, and 50 mg/L) exposure. Subsequently, a cohort of standard neurobehavioral tests including the light/dark preference (LDP) test, novel tank diving (NTD) test, novel object recognition (NOR) test, social interaction test (SIT), color-associated learning and memory test, and conditional place preference test were applied to delineate the general adverse effect of SAC. Specifically, in a concentration-dependent manner, SAC significantly increased the preference toward the dark side in the LDP test, inhibited exploratory behavior to the top arena in the NTD test, dampened the motivation to explore the novel object in the NOR test, weakened social preference in the SIT, and interfered in the color-based associative learning and memory ability. For example, in the LDP test, SAC remarkably increased the swimming distance of zebrafish in the dark part from 222 ± 34.6 (control group) to 675 ± 35.0 (50 mg/L group). Finally, the quantity of certain key neurotransmitters was further measured to determine the alteration induced by SAC on the brain chemistry. In total, the current research would provide a versatile neurobehavioral phenomics-based strategy to phenotypically screen the neurotoxicity of food additives at the overall animal level and provide a reference for further neurotoxicity exploration at the tissue and molecular level.

Monoglucosylation of rubusoside not only could increase its structural diversity but may also improve its taste. To biosynthesize the monoglucosyl rubusosides, a series of glycosyltransferases and glycosynthases were screened to identify the enzymes capable of specifically glycosylating the hydroxyl groups of the 13-O-β-d-glucosyl and 19-COO-β-d-glucosyl moieties. After structural characterization, the effect of structure on sweetness and taste was established based on these rubusoside-derived analogues, including two first characterized compounds. β-Monoglucosylation of two 2-hydroxyl groups, as well as α-monoglucosylations of the 4- and 6-hydroxyl groups of the 13-glucosyl moiety, could significantly increase the relative sweetness of rubusoside to 140 while maintaining or improving the taste quality. In contrast, monoglucosylations of other hydroxyl groups in our study usually decreased the taste quality of the rubusoside. Additionally, the possibility of a negative influence of these monoglucosylated derivatives on the function of islets was preliminarily excluded, which should facilitate the development of rubusoside-derived sweeteners.

Human sweet taste receptor (hSTR) recognizes a wide array of sweeteners, resulting in sweet taste perception. Maltitol and lactitol have been extensively used in place of sucrose due to their capability to prevent dental caries. Herein, several molecular modeling approaches were applied to investigate the structural and energetic properties of these two polyols/hSTR complexes. Triplicate 500 ns molecular dynamics (MD) simulations and molecular mechanics/generalized Born surface area (MM/GBSA)-based free energy calculations revealed that the TAS1R2 monomer is the preferential binding site for maltitol and lactitol rather than the TAS1R3 region. Several polar residues (D142, S144, Y215, D278, E302, R383, and especially N143) were involved in polyols binding through electrostatic attractions and H-bond formations. The molecular complexation process not only induced the stable form of ligands but also stimulated the conformational adaptation of the TAS1R2 monomer to become a close-packed structure through an induced-fit mechanism. Notably, the binding affinity of the maltitol/TAS1R2 complex (ΔGbind of -17.93 ± 1.49 kcal/mol) was significantly higher than that of the lactitol/TAS1R2 system (-8.53 ± 1.78 kcal/mol), in line with the experimental relative sweetness. These findings provide an in-depth understanding of the differences in the sweetness response between maltitol and lactitol, which could be helpful to design novel polyol derivatives with higher sweet taste perception.

Obesity is a global chronic disease linked to various diseases. Increased consumption of added sugars, especially in beverages, is a key contributor to the obesity epidemic. It is essential to reduce or replace sugar intake with low-calorie sweeteners. Here, a natural sweet protein, 3M-brazzein, was investigated as a possible sugar substitute. Mice were exposed to 3M-brazzein or 10% sucrose of equivalent sweetness, in drinking water to mimic human obesity development over 15 weeks. Consumption of 3M-brazzein in liquid form did not cause adiposity hypertrophy, resulting in 33.1 ± 0.4 g body weight and 0.90 ± 0.2 mm fat accumulation, which were 35.9 ± 0.7 g (p = 0.0094) and 1.53 ± 0.067 mm (p = 0.0031), respectively, for sucrose supplement. Additionally, 3M-brazzein did not disrupt glucose homeostasis or affect insulin resistance and inflammation. Due to its naturally low-calorie content, 3M-brazzein could also be a potential sugar substitute that reduces adiposity.

Leaf extracts of Stevia rebaudiana, composed of more than 10 steviol glycosides (SGs), are used as non-nutritive, table sugar (sucrose) alternatives due to their high level of sweetness and low caloric impact. They are often combined with the sugar alcohol erythritol to increase volume and reduce aftertaste. Little is known of the impact of sugar alternatives on the human gut microbiota in terms of the diversity, composition, and metabolic products. Testing of SGs and erythritol using six representatives of the gut microbiota in vitro found no impact on bacterial growth, yet treatment with erythritol resulted in an enhancement of butyric and pentanoic acid production when tested using a human gut microbial community. Furthermore, administration of SGs and erythritol to a Cebus apella model resulted in changes to the gut microbial structure and diversity. Overall, the study did not find a negative impact of SGs and erythritol on the gut microbial community.

Huanglongbing (HLB) disease has reduced orange yield and flavor quality in Florida. Orange juice (OJ) and peel molasses (PM) compounds are "from the named fruit" (FTNF) and were tested for their effects on HLB-affected OJ taste. These and other "target" compounds, reportedly found in citrus, were spiked into off-flavored, HLB-affected reference juices. The spiked juice was evaluated by a sensory panel in comparison with unspiked juice for "sweetness", "sourness", "bitterness", "astringency", and "aftertaste". Of the target compounds, feruloyl putrescine, taxifolin, and neodiosmin most effectively reduced "bitterness", feruloyl putrescine reduced "astringency" and "aftertaste", while feruloyl putrescine and neodiosmin enhanced perceived "sweetness", perhaps due to reduced bitterness. OJ and PM fractions containing reported bitter limonoids, hydroxycinnamates, hesperidin, and/or polymethoxylated flavones enhanced "sourness', "bitterness", "astringency", and "aftertaste", and/or suppressed perceived "sweetness" (perhaps due to enhanced bitterness). Other fractions, containing feruloyl putrescine and/or vicenin-2 enhanced "sweetness" and reduced "bitterness", "sourness", "astringency", and/or "aftertaste". These potentially FTNF compounds may be useful for management of HLB-affected OJ juice flavor.

Purple-pericarp sweetcorn (PPS) is a novel product, requiring both purple pigment development and maintenance of sweetness. Storage period and temperature had a profound impact on total anthocyanin accumulation (TAC) and sugar content. While TAC remained relatively unchanged during 14-day storage at 4 °C, the first recorded observation of continuing accumulation of anthocyanin and phenolic compounds was concurrent with an increase in purple pigment coverage across the surface of the kernel at 23 °C. TAC in PPS significantly increased, doubling after 14 days at 23 °C. Anthocyanin concentration and kernel coverage were also affected by harvest maturity. The results indicated that biosynthesis of anthocyanins is still occurring during postharvest storage of PPS. A significant decline in sugar concentration was also observed during storage with a greater decline at 23 °C. As anthocyanin accumulation and maintaining sweetness are important factors for sweetcorn, identifying storage temperatures that optimize both quality criteria are required.

This study describes the approach of 1H NMR metabolomic profiling for the differentiation of zucchini produced under different conditions of water irrigation (desalinated seawater −0.397 dS/m, 0.52 €/m3 vs groundwater −2.36 dS/m, 0.29 €/m3) and ventilation (surface area of the vent openings/greenhouse area was 15.0% for one sector and 9.8% for the other). Overall, 72 extracts of zucchini (Cucubirta pepo L. cv Victoria) under four different conditions were regularly analyzed during the spring-summer cycle from April to July 2017. We have found that zucchini plants irrigated with desalinated seawater increased the zucchini production yield, presented fruits with higher concentration of glucose, fructose, and vitamin B3, and displayed an increased antioxidant activity. On the contrary, plant groundwater irrigation produced the increment of sucrose level that could rise the sweetness perception of the fruits. Finally, the ventilation variable produced a higher concentration of trigonelline, histidine, and phe...

Ten novel C21 pregnane glycosides, extensumside C–L (1–10), were isolated as highly sweet-tasting substances from the edible pericarps of Myriopteron extensum (Wight) K. Schum by sensory-guided fractionation and purification. Their structures were determined through 1D and 2D NMR, such as HSQC, HMBC, 1H–1H COSY, HSQC-TOCSY, and ROESY, as well as other spectroscopic analysis combined with chemical evidence. These compounds shared the same aglycone, 3β,16α-dihydroxy-pregn-5-en-20-one, and contained the deoxysugar chain and the glucose chain which were linked to C-3 and C-16 of the aglycone, respectively. The sweetness potency was evaluated by a human sensory panel test and preliminary structure–taste relationship was discussed. The sweetness intensities of these compounds are between 50 and 400 times greater than that of sucrose. Furthermore, quantitation analyses of compounds 1, 3, 4, and 6 in different parts of M. extensum indicated that the concentrations of these sweet components in the pericarps are ob...

Mezcal, a traditional beverage that originated in Mexico, is produced from species of the Agavaceae family. The esters associated with the yeasts utilized during fermentation are important for improving the organoleptic properties of the beverage. We improved the ester contents in a mezcal beverage by using the yeast Kluyveromyces marxianus, which was engineered with the ATF1 gene. ATF1 expression in the recombinant yeast significantly increased compared with that in the parental yeast, but its fermentative parameters were unchanged. Volatile-organic-compound-content analysis showed that esters had significantly increased in the mezcal produced with the engineered yeast. In a sensory-panel test, 48% of the panelists preferred the mezcal produced from the engineered yeast, 30% preferred the mezcal produced from the wild type, and 15 and 7% preferred the two mezcal types produced following the routine procedure. Correlation analysis showed that the fruitiness/sweetness description of the mezcal produced using the ATF1-engineered K. marxianus yeast correlated with the content of the esters, whose presence improved the organoleptic properties of the craft mezcal beverage.

With the aim to investigate the sweet-tasting compounds in Derris eriocarpa How (a substitute for licorice in "Zhuang" and "Dai" ethnopharmacy in Guangxi and Yunnan provinces of China) as well as to ascertain why the stem of D. eriocarpa can be used to substitute for licorice in the sweetness taste aspect, taste sensory-guided fractionation was conducted to isolate sweet constituents from the extract of D. eriocarpa. Four sweet-tasting triterpenoid saponins were obtained, including millettiasaponin A (1) and three new saponins named derrisaponins A-C (2-4). The sweetness potency was evaluated by a human sensory panel test. The sweetness intensities of compounds 1-4 were determined to be approximately 150, 80, 2, and 0.5 times relative to sucrose at the concentration of 1%, respectively, of which compounds 1 and 2, with a free carboxyl group at the C-30 position, showed more potent sweetness intensity. In addition, compounds 1 and 2 showed no acute toxic activity at doses of 250 and 400 mg/kg of body weight, respectively, assessed through caudal vein injection to ICR mice. The contents of the sweetest compounds in stems were analyzed quantitatively as 352.80 mg/kg for compound 1 and 1887.60 mg/kg for compound 2 performed by ultra-performance liquid chromatography-tandem mass spectrometry.

Stevia is one of the sweeteners with the greatest consumer demand because of its natural origin and minimal calorie content. Steviol glycosides (SG) are the main active compounds present in the leaves of Stevia rebaudiana and are responsible for its sweetness. However, recent in vitro studies in HEK 293 cells revealed that SG specifically activate the hT2R4 and hT2R14 bitter taste receptors, triggering this mouth feel. The objective of this study was to characterize the interaction of SG with these two receptors at the molecular level. The results showed that SG have only one site for orthosteric binding to these receptors. The binding free energy (ΔGbinding) between the receptor and SG was negatively correlated with SG bitterness intensity, for both hT2R4 (r = −0.95) and hT2R14 (r = −0.89). We also determined, by steered molecular dynamics simulations, that the force required to extract stevioside from the receptors was greater than that required for rebaudioside A, in accordance with the ΔG values obtai...

Traditional paocai brine (PB) is continuously propagated by back-slopping and contains numerous lactic acid bacteria (LAB) strains. Although PB is important for the quality of paocai (Chinese sauerkraut), the taste features, taste-related compounds of PB-paocai and the effects of LAB communities from PB on the taste compounds remain unclear. An electronic tongue was used to evaluate the taste features of 13 PB-paocai samples. Umami, saltiness, bitterness, sweetness, and aftertaste astringency were the main taste features of PB-paocai. A total of 14 compounds were identified as discriminant taste markers for PB-paocai via gas chromatography-mass spectrometry (GC-MS)-based multimarker profiling. A LAB co-culture (Lactobacillus plantarum, Lactobacillus buchneri, and Pediococcus ethanoliduran) from PB could significantly increase glutamic acid (umami), sucrose (sweetness), glycine (sweetness), lactic acid (sourness), and γ-aminobutyric acid in PB-paocai, which would endow it with important flavor features. Such features could then facilitate starter screening and fermentation optimization to produce paocai-related foods with better nutritional and sensory qualities.

A practical method for simultaneously quantifying fructose and ethanol contents in wines using (13)C quantitative nuclear magnetic resonance (qNMR) spectroscopy is reported. Less than 0.6 mL of wine is needed, and the method leaves an unmodified sample available for subsequent testing or additional analyses. The relative ratios of the five known fructose isomers in ethanolic solutions at different pH and their variations with the temperature are also reported. The data are correlated with the sweetness of wines. The technique was applied to commercially available wines, and the results are compared to other methods. Sugar levels above 0.6 g/L can also be measured. A simple adaptation of the method permits measurement of different carbohydrates using integration of single peaks for each compound, in combination with an external reference (13)C qNMR spectrum of a sample with a known concentration. The method can be applied at all stages of wine production, including grape must, during fermentation, and before and after bottling.

Knowledge of the formation of oral coatings and their influence on subsequent taste perception is necessary to understand possible taste-masking effects by oil coatings. This study investigated (a) the dynamics of the formation of oral oil coatings formed by o/w emulsions and (b) the effect of oral oil coatings on subsequent sweetness perception of sucrose solutions. In vivo fluorescence was used to quantitate the oil fraction deposited on the tongue after oral processing of oil-in-water emulsions for different times. A trained panel evaluated sweetness perception of sucrose solutions after orally processing the emulsions. The oil fraction reached its maximum value within the first 3 s of oral processing. The oil fraction did not significantly affect subsequent sweetness perception of sucrose solutions. It is suggested that the oil droplets deposited on the tongue did not form a hydrophobic barrier that is sufficient to reduce the accessibility of sucrose to taste buds.

Ten novel C21 pregnane glycosides, Extensumside C–L (1–10), were isolated as highly sweet-tasting substances from the edible pericarps of Myriopteron extensum (Wight) K. Schum by sensory-guided fractionation and purification. Their structures were determined through 1D and 2D NMR, such as HSQC, HMBC, 1H-1H COSY, HSQC-TOCSY and ROESY, as well as other spectroscopic analysis combined with chemical evidences. These compounds shared the same aglycone, 3β,16α-dihydroxy-preg-5-en-20-one, and contained the deoxysugar chain and the glucose chain which were linked to C-3 and C-16 of the aglycone, respectively. The sweetness potency was evaluated by a human sensory panel test and preliminary structure-taste relationship was discussed. The sweetness intensities of these compounds are between 50 to 400 times greater than that of sucrose. Furthermore, quantitation analyses of compounds 1, 3, 4, and 6 in different parts of M. extensum indicated that the concentrations of these sweet components in the pericarps are obvi...

Antioxidant capacity, quality, and anthocyanin and nutrient contents of 106 peach cultivars from different breeding programs were evaluated at the Estació Experimental de Lleida, IRTA (Catalonia, Spain), during two growing seasons (2010 and 2011). High variability was found among cultivars within each quality trait, where different cultivars were scored as the best and the worst. For example, a 5-fold range (2.17-12.07 g of malic acid L⁻¹), 6-fold range (144.20-711.73 μg of Trolox g⁻¹ of FW), and 11-fold range (0.70-11.43 mg of cyanidin-3-glucoside kg⁻¹ of FW) were observed in titratable acidity, relative antioxidant capacity, and anthocyanin content, respectively. The breeding program within each fruit type (melting peach, nectarine, and flat peach) and qualitative pomological traits also had significant effects on the quality. Nevertheless, each breeding program had specific characteristics that distinguished it from the others. Even so, within each breeding program, there is high variability among cultivars. Therefore, growers should not base their strategy exclusively on the choice of breeding program. Principal component analysis for each fruit type (melting peach, nectarine, nonmelting peach, and flat peach) allowed a selection of a set of cultivars from different breeding programs with the highest quality performance. For example, cultivars such as 'Azurite', 'IFF 1230', 'Amiga', 'Fire Top', 'African Bonnigold', 'Ferlot', 'Mesembrine', and 'Platifirst' had higher sweetness and flavor compared to the others. Therefore, this study could help breeders to make decisions for the selection of new cultivars able to improve the quality features of fruit intake, technicians to know better quality performance of peach cultivars, and consumers to meet their expectations for fruit with high health benefits and a specific taste.

One major red wine mouthfeel characteristic, astringency, is derived from grape-extracted tannins and is considered to be a result of interaction with salivary proteins and the oral mucosa. To improve our understanding of the role that the enthalpy of interaction of tannin with a hydrophobic surface (tannin activity) has in astringency perception, a chromatographic method was used to determine the tannin concentration and activity of 34 Cabernet Sauvignon wines, as well as sensory analysis done on 13 of those wines. In addition, astringency-relevant matrix parameters (pH, titratable acidity, ethanol, glucose, and fructose) were measured across all wines. Tannin activity was not significantly correlated with any matrix variables, and the perception of drying and grippy was not correlated with tannin concentration and activity. However, ethanol content was well related to mouthfeel attributes and appeared to drive perceived drying. Although fructose and glucose content were well correlated, they did not drive the perception of sweetness, which is explained by the well-known mixture suppression effect.

Soluble sugar contents in mature fruits of 45 peach accessions were quantified using gas chromatography analysis. Sucrose is the predominant sugar in mature fruit, followed by glucose and fructose, which have similar concentrations. Overall, sucrose metabolism and accumulation are crucial determinants of sugar content in peach fruit, and there is a wide range of sucrose concentrations among peach genotypes. To understand the mechanisms regulating sucrose accumulation in peach fruit, expression profiles of genes involved in sucrose metabolism and transport were compared among four genotypes. Two sucrose-cleaving enzyme genes (SUS4 and NINV8), one gene involved in sucrose resynthesis (SPS3), and three sugar transporter genes (SUT2, SUT4, and TMT2) were prevalently expressed in peach fruit, and their expression levels are significantly correlated with sucrose accumulation. In contrast, the VAINV genes responsible for sucrose cleavage in the vacuole were weakly expressed in mature fruit, suggesting that the sucrose-cleaving reaction is not active in the vacuole of sink cells of mature peach fruit. This study suggests that sucrose accumulation in peach fruit involves the coordinated interaction of genes related to sucrose cleavage, resynthesis, and transport, which could be helpful for future peach breeding.

The sensory attributes and flavor chemistry of grilled beef striploins (M. longissimus lumborum, n = 42) varying widely in marbling from commercial production types typical for Southern Australia were extensively characterized. Striploins from Angus grass-fed yearlings (5.2-9.9% intramuscular fat), Angus grain-finished steers (10.2-14.9%), and Wagyu grass-fed heifers (7.8-17.5%) were evaluated. Inherent differences between samples from grass- and grain-fed Angus cattle were minimal when the intramuscular fat content was above ∼5%. After adjusting for intramuscular fat, Wagyu samples had more intense flavor and higher tenderness and juiciness compared to Angus grass-fed samples. Grilled beef flavor, dairy fat, and sweetness increased with the marbling level, and sourness and astringency decreased. Tenderness and juiciness increased with the marbling level and were correlated with Warner-Bratzler peak force measurements. Trained panel sensory differences in flavor corresponded with increases in aroma volatiles and changes in nonvolatile flavor compounds. Unsaturated fatty acids with potential health benefits (vaccenic, oleic, and rumenic acids) increased with the level of marbling.

Taste receptors have been defined at the molecular level in the past decade, and cell-based assays have been developed using cultured cells heterologously expressing these receptors. The most popular approach to detecting the cellular response to a tastant is to measure changes in intracellular Ca(2+) concentration using Ca(2+)-sensitive fluorescent dyes. However, this method cannot be applied to food-derived samples that contain fluorescent substances. To establish an assay system that would be applicable to fluorescent samples, we tested the use of Ca(2+)-sensitive photoproteins, such as aequorin and mitochondrial clytin-II, as Ca(2+) indicators in a human sweet taste receptor assay. Using these systems, we successfully detected receptor activation in response to sweetener, even when fluorescent compounds coexisted. This luminescence-based assay will be a powerful tool to objectively evaluate the sweetness of food-derived samples even at an industry level.

Oral stimulation with high-tastant concentrations that are alternared with low-tastant concentrations or water rinses (pulsatile stimulation) results in taste intensity ratings that are higher than continuous stimulation with the same average tastant concentration. This study tested the combined effects of taste pulsation rate and viscosity on pulsation-induced taste enhancement in apple juice. According to a tastant-kinetics hypothesis, less pulsation-induced taste enhancement is expected at enhanced pulsation rates in the high-viscous proximal stimulus compared to lower viscous stimuli. High-concentration sucrose apple juice pulses and low-concentration sucrose apple juice intervals were alternated at different pulsation periods (pulse + interval in seconds) every 2.5 s (period length = 5 s) or every 1.25 s (period length = 2.5 s). Pulsed stimuli were presented at two viscosity levels by the addition of pectin (0 and 10 g/L). Sweetness intensities of pulsed stimuli were compared to a continuous reference of the same net but nonalternating sucrose concentration. Sweetness ratings were higher for pulsatile stimuli than for continuous stimuli. In low-viscous stimuli, enhancement depended on the pulsation period and peaked at 5 s periods. In high-viscous stimuli, the same enhancement was observed for both pulsation periods. These results contradict a tastant-kinetics hypothesis of viscosity-induced taste suppression because impaired tastant kinetics by viscosity would predict the opposite: lower pulsation-induced taste enhancement for viscous stimuli, especially at higher pulsation rates. Instead, these observations favor an explanation based on perceptual texture-taste interactions, which predict the observed independence between viscosity and pulsation rate.

A new device for evaluating the continuity of taste was developed with the use of surface plasmon resonance (SPR). The model of lingual cells was constructed with liposomes immobilized onto an L1 sensor chip for SPR. Using this device, we classified food components into three categories according to the sensorgram pattern and residual ratio on lipid bilayer. Samples in group A strongly interacted with lipid bilayer, those in group B poorly interacted, and those in group C belong to neither group A nor group B. Sweet proteins and gymnemic acids that prolonged sweet perception were categorized in group A. Almost all the carbohydrates investigated and aspartame, of which the taste perception does not continue, belonged to group B. This device made it possible to detect the interaction with lipid bilayer and dissected the mechanism of taste continuity.

A total of 28 new five-membered aromatic ring thiazolyl-, benzothiazolyl-, and thiadiazolylsulfamates, as their sodium salts, have been synthesized and combined with 30 known similar heterocyclic sulfamates to create a database for the study of structure-activity (taste) relationships (SARs) in this heterocyclic subgroup, which is known to contain a somewhat disproportionate number of sweet compounds compared to other groups of tastants. A series of nine parameters (descriptors) to describe the properties of the sulfamate anions were calculated in Spartan Pro and HyperChem programs. These are the highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), length of the molecule, dipole moment, area, volume, E(solv), sigma (from the literature), and log P. The taste data for all 58 compounds were categorized into three classes, namely, sweet (S), nonsweet (N), and nonsweet/sweet (N/S). Discriminant analysis only classified 44 of the 58 compounds correctly. Classification and regression tree analysis (CART) using the S_ Plus program proved highly effective, in that the derived tree correctly classified 46 compounds from a training set of 48 and, from a computer randomly selected test set of 10 compounds, 7 had their taste correctly predicted. A second tree was grown using the additional taste category N/S, and this tree also performed extremely well, with 8 of the 10 compounds in the test set correctly classified. These trees should be very reliable for predicting the tastes of other heterocyclic sulfamates, which belong to the subset used here.

A fullerenol-based synthetic sweetness receptor model, consisting of polyhydroxy groups for potential hydrogen bond donor along with a spherical hydrophobic center, was proposed according to the widely accepted sweetness hypothesis. An isothermal titration calorimetry (ITC) technique was used to study mimetic interaction of this sweet receptor model with a series of sweeteners having increasing sweetness intensity. The results showed that ITC is an effective method to provide thorough and precise characterization of the energies of molecular complex formation. Binding of all of the studied sweeteners with fullerenols was found through two sets of site models. More heat was released from sweeter synthetic compounds binding with fullerenols than from less sweet carbohydrates. The results imply that hydrogen bond formation is necessary for the sweeteners to bind to the fullerenol receptor in the first stage, whereas hydrophobic effect and conformation changes that lead to favorable entropy changes occur in most cases. The preliminary results of this study help to cover the lack of information about the thermodynamic basis of understanding of the initiation of the sweet sensation. It also adds complementary physicochemical measurements available for comparison with the sweetness hypothesis. On the other hand, a correlation between the thermodynamic parameters and sweetness intensity has been made as well, which exhibits potential as a useful tool in sensory analysis.

The influence of flavor solvent [triacetin (TA), propylene glycol (PG), medium chained triglycerides (MCT), or no flavor solvent (NFS)] on the flavor release profile, the textural properties, and the sensory perception of a sugar-free chewing gum was investigated. Time course analysis of the exhaled breath and saliva during chewing gum mastication indicated that flavor solvent addition or type did not influence the aroma release profile; however, the sorbitol release rate was statistically lower for the TA formulated sample in comparison to those with PG, MCT, or NFS. Sensory time-intensity analysis also indicated that the TA formulated sample was statistically lower in perceived sweetness intensity, in comparison with the other chewing gum samples, and also had lower cinnamon-like aroma intensity, presumably due to an interaction between sweetness intensity on aroma perception. Measurement of the chewing gum macroscopic texture by compression analysis during consumption was not correlated to the unique flavor release properties of the TA-chewing gum. However, a relationship between gum base plasticity and retention of sugar alcohol during mastication was proposed to explain the different flavor properties of the TA sample.

Seedless triploid watermelons have increased in popularity since the early 1990s, and the demand for seedless fruit is on the rise. Sweetness and sugars are crucial breeding focuses for fruit quality. Volatiles also play an important role; yet, we found no literature for seedless varieties and no reports using solid-phase microextraction (SPME) in watermelon. The objective of this experiment was to identify volatile and semivolatile compounds in five seedless watermelon varieties using carboxen divinylbenzene polydimethylsiloxane solid-phase microextraction (SPME) with gas chromatography-mass spectrometry (GC-MS). Fully ripe watermelon was squeezed through miracloth to produce rapid juice extracts for immediate headspace SPME GC-MS. Aldehydes, alcohols, ketones, and one furan (2-pentyl furan, a lipid oxidation product) were recovered. On the basis of total ion count peak area, the most abundant compounds in five varieties were 3-nonen-1-ol/(E,Z)-2,6-nonadienal (16.5-28.2%), (E)-2-nonenal (10.6-22.5%), and (Z)-6-nonenal (2.0-11.3%). Hexanal was most abundant (37.7%) in one variety (Petite Perfection) [corrected] The most abundant ketone was 6-methyl-5-hepten-2-one (2.7-7.7%). Some sensory attributes reported for these compounds are melon, citrus, cucumber, orange, rose, floral, guava, violet, vegetable, green, grassy, herbaceous, pungent, fatty, sweet, and waxy. Identifying and relating these compounds to sensory attributes will allow for future monitoring of the critical flavor compounds in seedless watermelon after processing and throughout fresh-cut storage.

International audience; Yeast lees influence the organoleptic properties of wines by increasing their sweet taste. This effect is in part due to the protein Hsp12p, which is regulated by different stress response pathways in Saccharomyces cerevisiae. This work investigated the genetics and environmental factors influencing the expression level of the HSP12 gene in an enological context. RT-qPCR confirmed that the HSP12 expression level is regulated by temperature change and ethanol content during the alcoholic fermentation but not by the sugar content. Moreover, this gene shows an important variation according to the yeast strain used. For the first time yeast strain is demonstrated to play an important role in the perception of sweetness in red wine due to post-fermentation lees autolysis. Interestingly, a correlation between the expression level of HSP12 and the sweetness perception was found using yeast strains of different origins. All of the findings provide new insights on the contribution of yeast to wine taste.

Twenty monosubstituted phenylsulfamates (cyclamates) have been synthesized and have had their taste portfolios determined. These have been combined with 63 compounds already in the literature to give a database of 83 ortho, meta, and para compounds. A training set of 75 compounds was randomly selected leaving eight compounds as a test set. A series of nine predictors determined with Corey-Pauling-Koltun models, calculated from the PC SPARTAN PRO program and Hammett sigma values taken mainly from the literature, have been used to establish structure-taste relationships for these types of sweeteners. The taste panel data for all compounds were categorized into three classes, namely, sweet (S), nonsweet (N), and sweet/nonsweet (N/S), and a novel "sweetness value" or weighting was also calculated for each compound. Linear and quadratic discriminant analysis were first used with the S, N, and N/S data, but the results were somewhat disappointing. Classification and regression tree analysis using the sweetness values for all 75 compounds was more successful, and only 14 were misclassified and six of the eight test set compounds were correctly classified. For the 29 meta compounds, one subset using just two parameters classified 83% of these compounds. Finally, using various methods, predictions were made on the likely tastes of a number of meta compounds and a striking agreement was found between the tree prediction and those given by earlier models. This appears to offer a strong vindication of the tree approach.

The influence of type and concentration of carboxymethyl cellulose (CMC) on flavor and textural properties of custard desserts was examined. A synthetic strawberry flavor mixture was used to flavor the custards; it comprised 15 volatile flavor compounds. The viscosity of the custards was determined using rheometric measurements. Static headspace gas chromatography and in-nose proton transfer reaction-mass spectrometry analyses were conducted to determine the custards' volatile flavor properties. Perceived odor, flavor, and textural properties were assessed in sensory analysis experiments using magnitude estimation against a fixed modulus. Both type and concentration of CMC altered the viscosity of the custards. Softer custards had higher static headspace flavor concentrations. On the contrary, firmer custards demonstrated higher in-nose flavor concentrations. In sensory analysis, firmer custards showed higher thickness and lower sweetness intensities than their low-viscosity counterparts. The thickness perception corresponded to the viscosity of the custards. Removal of sucrose from the custards affected sweetness intensity only and not the intensity of other attributes. Therefore, the influence of the viscosity of the custards on the release of sweet-tasting components is held responsible for the effect on perceived sweetness intensity. Odor intensities were generally higher for the low-viscosity custard, whereas fruity flavor intensities were higher for the firmer custards. Odor intensities correlated with static headspace concentrations and flavor intensities related reasonably well with in-nose concentrations. Opening and closing of the nasal cavity is regarded as an important factor determining the discrepancy between static and in-nose measurements.

Stevia rebaudiana standardized extracts (SSEs) are used as natural sweeteners or dietary supplements in different countries for their content of stevioside or rebaudioside A. These compounds possess up to 250 times the sweetness intensity of sucrose, and they are noncaloric and noncariogenic sweeteners. The aim of this study was to investigate the in vitro transformation of stevioside and rebaudioside A after incubation with human microflora, the influence of these sweeteners on human microbial fecal community and which specific groups metabolize preferentially stevioside and rebaudioside A. The experiments were carried out under strict anaerobic conditions in batch cultures inoculated with mixed fecal bacteria from volunteers. The hydrolysis was monitored by HPLC coupled to photodiode array and mass spectrometric detectors. Isolated bacterial strains from fecal materials incubated in selective broths were added to stevioside and rebaudioside A. These sweeteners were completely hydrolyzed to their aglycon steviol in 10 and 24 h, respectively. Interestingly, the human intestinal microflora was not able to degrade steviol. Furthermore, stevioside and rebaudioside A did not significantly influence the composition of fecal cultures; among the selected intestinal groups, bacteroides were the most efficient in hydrolyzing Stevia sweeteners to steviol.

Application of a novel screening procedure, the comparative taste dilution analysis (cTDA), on the non-solvent-extractable reaction products formed in a thermally processed aqueous solution of glucose and l-alanine led to the discovery of the presence of a sweetness-enhancing Maillard reaction product. Isolation, followed by LC-MS and 1D- and 2D-NMR measurements, and synthesis led to its unequivocal identification as N-(1-carboxyethyl)-6-(hydroxymethyl)pyridinium-3-ol inner salt. This so-called alapyridaine, although being tasteless itself, is the first nonvolatile, sweetness-enhancing Maillard reaction product reported in the literature. Depending on the pH value, the detection thresholds of sweet sugars, amino acids, and aspartame, respectively, were found to be significantly decreased when alapyridaine was present; for example, the threshold of glucose decreased by a factor of 16 in an equimolar mixture of glucose and alapyridaine. Studies on the influence of the stereochemistry on taste-enhancing activity revealed that the (+)-(S)-alapyridaine is the physiologically active enantiomer, whereas the (-)-(R)-enantiomer did not affect sweetness perception at all. Thermal processing of aqueous solutions of alapyridaine at 80 degrees C demonstrated a high thermal and hydrolytic stability of that sweetness enhancer; for example, more than 90 or 80% of alapyridaine was recovered when heated for 5 h at pH 7.0, 5.0, or 3.0, respectively.

Several cultivars of strawberries (Fragaria sp.), grown under different conditions, were analyzed by both sensory and instrumental methods. The overall appreciation, as expressed by consumers, was mainly reflected by attributes such as sweetness and aroma. No strong correlation was obtained with odor, acidity, juiciness, or firmness. The sensory quality of strawberries can be assessed with a good level of confidence by measuring the total sugar level ( degrees Brix) and the total amount of volatile compounds. Sorting out samples using the score obtained with a hedonic test (called the "hedonic classification method") allowed the correlation between consumers' appreciation and instrumental data to be considerably strengthened. On the basis of the results obtained, a quality model was proposed. Quantitative GC-FID analyses were performed to determine the major aroma components of strawberries. Methyl butanoate, ethyl butanoate, methyl hexanoate, cis-3-hexenyl acetate, and linalool were identified as the most important compounds for the taste and aroma of strawberries.

Four isomers of the L-aspartyl-D-alanine fenchyl esters were prepared as potential peptide sweeteners. L-Aspartyl-D-alanine (+)-alpha-fenchyl ester and L-aspartyl-D-alanine (-)-beta-fenchyl ester showed sweetness with potencies 250 and 160 times higher than that of sucrose, respectively. In contrast, L-aspartyl-D-alanine (+)-beta-fenchyl ester and L-aspartyl-D-alanine (-)-alpha-fenchyl ester had the highest sweetness potencies at 5700 and 1100 times that of sucrose, respectively. In particular, L-aspartyl-D-alanine (-)-alpha-fenchyl ester had an excellent sweetness quality; but L-aspartyl-D-alanine (+)-beta-fenchyl ester did not have an excellent quality of sweetness because it displayed an aftertaste caused by the strong sweetness.

Four different colored carrots, orange, purple with orange core, yellow, and white, were examined for their content of phenolics, antioxidant vitamins, and sugars as well as their volatiles and sensory responses. A total of 35 volatiles were identified in all carrots, 27 positively. White carrot contained the highest content of volatiles, followed by orange, purple, and yellow. In total, 11, 16, 10, and 9 phenolic compounds were determined for the first time in orange, purple, yellow, and white carrots, respectively. Of these, chlorogenic acid was the most predominant phenolic compound in all carrot varieties. Differences (p < 0.05) in relative sweetness, the contents of vitamin C and alpha- and beta-carotenes, and certain flavor characteristics were observed among the colored carrot varieties examined. Purple carrots contained 2.2 and 2.3 times more alpha- and beta-carotenes (trace in yellow; not detected in white) than orange carrots, respectively. Purple carrot may be used in place of other carrot varieties to take advantage of its nutraceutical components.

Enzymatically modified licorice extract (EMLE) is a natural sweetener, which is prepared with cyclodextrin glucanotransferase. It is used because of its unique properties such as higher solubility and better taste than those of licorice extract. In the present paper, the structures of six major constituents isolated from EMLE were determined, and their sweetness was studied. The isolated compounds were glycyrrhizin (1), 3-O-[beta-D-glucuronopyranosyl-(1--2)-beta-D-glucuronopyranosyl]liquiritic acid (2), and their derivatives glucosylated at the C-4 position of the terminal glucuronopyranose with additional one (3 and 4, respectively) and two (5 and 6, respectively) glucose moieties. Compounds 1 and 2 are the major and minor sweet constituents in licorice extract, respectively. Compounds 3-6 are new compounds isolated for the first time. Compound 2 was sweeter than compound 1. Interestingly, compound 3, which is a monoglucosylated derivative of compound 1, was sweeter than compound 4. The sweetness of both compounds was lower than that of the parent compounds, while the lingering sweet aftertaste was markedly improved. Compounds 5 and 6, which have two additional glucose moieties, showed only slight sweetness.

Carbohydrates are known to be important precursors in the development of roasted peanut quality. However, little is known about their genotypic variation. A better understanding of the role of carbohydrates in roasted peanut quality requires first an understanding of the genotypic variation in the soluble carbohydrate components. Ion exchange chromatography was used to isolate 20 different carbohydrate components in 52 genotypes grown in replicated trials at two locations. Inositol, glucose, fructose, sucrose, raffinose, and stachyose were quantitated, and 12 unknown peaks were evaluated on the basis of the peak height of the unknown relative to the cellobiose internal standard peak height. Peaks tentatively identified as verbascose and ajugose could not be properly integrated because of tailing. Of the 18 carbohydrates that were estimated, 9 exhibited significant variation between test environments, 5 among market types, 14 among genotypes within market types, and 11 exhibited some significant form of genotype x environment interaction. Genotypes accounted for 38-78% of the total variation for the known components, suggesting that broad-sense heritability for these components is high. The observed high genotypic variation in carbohydrate components is similar to the high genotypic variation observed for the sweetness attribute in roasted peanuts, which raises the question regarding possible interrelationships. The establishment of such interrelationships could be most beneficial to peanut breeding programs to ensure the maintenance of flavor quality in future peanut varieties.

Physicochemical analysis of processed strained product was performed on 10 carrot genotypes grown in Texas (TX) and Georgia (GA). Carrots from GA experienced hail damage during growth, resulting in damage to their tops. Measurements included pH, moisture, soluble phenolics, total carotenoids, sugars, organic acids, and isocoumarin (6-MM). Sensory analysis was conducted using a trained panel to evaluate relationships between chemical and sensory attributes of the genotypes and in carrots spiked with increasing levels of 6-MM. Preharvest stress conditions in GA carrots seemed to elicit a phytoalexic response, producing compounds that impacted the perception of bitter and sour flavors. Spiking 6-MM into strained carrots demonstrated the role bitter compounds have in lowering sweetness scores while increasing the perception of sour flavor. Screening fresh carrots for the phytoalexin 6-MM has the potential to significantly improve the sensory quality of processed products.

In structure−taste relationships of sweet substances, conformational analysis is important for the definition of the “active conformation” which actually interacts with the sweet taste receptor. This paper describes the synthesis and taste of some isovanillyl derivatives having a rigid structure, which can mimick only one possible conformation of their flexible analogues. We report also the solid state conformation of a sulfur-containing sweet isovanillyl derivative which was established by X-ray analysis. The relationships between conformation and taste were studied by comparison with the current models of the sweet taste receptor and by principal components analysis (PCA) using geometrical descriptors, followed by factor and cluster analysis. A strong correlation was proven between taste and geometry, which is able to explain the taste of rigid derivatives as well as the difference of taste between the two enantiomers of the same compound. Keywords: Sweetness; taste; isovanillyl derivatives; conformatio...

Several different QSAR techniques have been applied to sweetness data for 50 sulfamates, RNHSO3Na (21 sweet, 20 sweet-bitter, and 9 bitter). Stepwise discriminant analysis has been used to separate...

The major proteins in Sauvignon Blanc wine are grape (Vitis vinifera) thaumatin-like proteins. Although authentic thaumatin from miracle fruit (Thaumattococcus danielli) is intensely sweet, a panel of 26 participants did not identify a wine protein fraction containing 82% thaumatin-like proteins at either 22, 220, or 2200 mg/L in aqueous solution as sweet. Thus, it is highly unlikely that grape thaumatin-like proteins, which would be present in wine at a substantially lower concentration than the maximum concentration tested, contribute sweetness to wine.

Twenty-four analogues of the sweet compound 2-(4-methoxybenzoyl)benzoic acid 1 were synthesized and tasted. The structure−sweet taste relationships were studied by means of principal component analysis and by comparison with the existing sweet receptor models. Three possible glucophores were identified, which could correspond to the sites B, E1, and E2 of the Tinti−Nofre model. Some similarities between this class of compounds and isovanillic sweeteners were found. Keywords: Sweetness; SAR (structure−activity relationships); taste

Strips from five sweetpotato (SP) cultivars (cv.) representing two different texture/flavor types were prepared and frozen. They were fried and their flavor and texture evaluated by sensory panels. Selected physical and compositional analyses were performed on raw and fried SP. An untrained preference panel tended to score the flavor of the sweeter types highest and the texture of the firm types higher than sweet types. A trained profile panel identified and scored flavor notes and texture categories. This research indicated that the intensity of the flavor notes sweetness and starch and the intensity of texture notes first-bite moistness and first-bite hardness were highly correlated with some of the compositional parameters. Correlation between compositional parameters and the flavor and texture note intensities listed above could be developed into a system to predict those sensory properties in newly developed selections without having to resort to sensory analyses. Keywords: Texture profile analysis; ...

The contribution of volatile aroma compounds to the overall composition and sensory perception of wine is well recognized. The classical targeted measurement of volatile compounds in wine using GC-MS is laborious and only a limited number of compounds can be quantified at any time. Application of an automated multivariate curve resolution technique to nontargeted GC-MS analysis of wine makes it possible to detect several hundred compounds within a single analytical run. Hunter Valley Semillon (HVS) is recognized as a world class wine with a range of styles. Subtle characters reliant upon the development of bottle maturation characteristics are a feature of highly esteemed HVS. In this investigation a metabolomic approach to wine analysis, using multivariate curve resolution techniques applied to GC-MS profiles coupled with full descriptive sensory analysis, was used to determine the objective composition of various styles of HVS. Over 250 GC-MS peaks were extracted from the wine profiles. Sensory scores were analyzed using PARAFAC prior to development of predictive models of sensory features from the extracted GC-MS peak table using PLS regression. Good predictive models of the sensorial attributes honey, toast, orange marmalade, and sweetness, the defining traits for HVS, could be determined from the extracted peak tables. Compound identification for these rated attributes indicated the importance of a range of ethyl esters, aliphatic alcohols and acids, ketones, aldehydes, furanic derivatives, and norisoprenoids in the development of HVS and styles. The development of automated metabolomic data analysis of GC-MS profiles of wines will assist in the development of wine styles for specific consumer segments and enhance understanding of production processes on the ultimate sensory profiles of the product.

Sensory-directed fractionation of traditional balsamic vinegar of Modena (TBV) led to the identification of the sweet-bitter tasting hexose acetates 6-O-acetyl-α/β-d-glucopyranose and 1-O-acetyl-β-d-fructopyranose as well as the previously unknown sweetness modulator 5-acetoxymethyl-2-furaldehyde. Taste re-engineering experiments and sensory time-intensity studies confirmed 5-acetoxymethyl-2-furaldehyde to contribute to the typical long-lasting sweet taste quality of TBV. Moreover, the response of the sweet taste receptor to this furaldehyde was verified by means of a functional hTAS1R2/hTAS1R3 receptor assay. Quantitative analysis of a total of 59 nonvolatile sensometabolites and taste modulators revealed higher concentrations of the sweet-modulating 5-acetoxymethyl-2-furaldehyde, nonvolatile organic acids and polyphenols such as wood-derived ellagitannins, and lower concentrations of acetic acid in the premium quality TBV when compared to balsamic vinegar of Modena (BV). Quantitative monitoring of sensometabolites throughout TBV manufacturing, followed by agglomerative hierarchical clustering and sensomics heatmapping, gave molecular insights into the taste alterations occurring during TBV maturation.

Bell pepper C. annuum cv. Mazurka and cv. Evident, at three maturation stages, were evaluated sensorily on flavor attributes. Green bell peppers scored mainly on the attributes bitterness, grassy, cucumber, and green bell pepper aroma, whereas the attributes sweetness, sourness, and red bell pepper aroma were distinctive for the red ones. Sugars and organic acids were determined by high-performance liquid chromatography (HPLC), and concentrations of different ions of the acids were calculated from their dissociation equilibria. Principal component analysis (PCA) demonstrated that HPLC data of fructose, glucose, total sugar, and dry matter content were related to the attribute sweetness in the red maturation stage 0

Chemical and biochemical properties of standard, hybrid, and grafted melons cultivated under the same agricultural conditions in adjacent fields in the Cumra region of Turkey were investigated and compared based on pH, Brix, antioxidant activity, total phenolics, ascorbic acid, individual phenolics, sugar, and organic acid values. Seventeen different phenolic constituents were quantified by reverse phase high-performance liquid chromatography (RP-HPLC). The highest phenolic acid variability and content were detected in the standard melon. Sugar and organic acid compositions of melon cultivars were tested by capillary electrophoresis, and significant differences in types and contents of individual sugars and organic acids were determined among the cultivars. Standard Cinikiz Cumra melons had the highest ascorbic acid, total phenolics, and total sugar contents. The fructose/glucose ratio increased three times in grafted melon as compared with standard melon. While sugar alcohol mannitol existed in the standard and hybrid cultivars, this constituent disappeared in the grafted types. Citric acid found in the standard cultivar was not detected in the hybrid and grafted types. Consequently, it was concluded that the nutritional value of melons changed by the application of hybridization, grafting, or standard (open pollinated) production methods. The standard melon was found to have the highest score in terms of taste, because of its highest sweetness and sourness. It was also found preferable because of its high antioxidant activity, total phenolic and ascorbic acid contents.