Higher Bitterness Research Articles

Analysis of the effects of biopolymer encapsulation and sodium replacement combination technology on the quality characteristics and inhibition of sodium absorption from sausage in mice

The effects of biopolymer encapsulation and sodium replacement combination technology on quality characteristics (i.e., bitter taste) and inhibition of sodium absorption from pork sausage in mice were evaluated. The sausages were divided into three different sodium replacement groups (none, 40%, and 50%) and three different biopolymer encapsulation groups (none, cellulose, and chitosan) in combination. In groups with 50% sodium replacement by KCl and MgCl2, T8 (chitosan encapsulation) showed the highest inhibition of the sodium absorption rate. However, chitosan encapsulation groups (T2, T5, and T8) had higher bitterness and lower overall acceptability than other treatment groups. In contrast, in the group with 40% sodium replacement by KCl, T4 (cellulose encapsulation) exhibited the highest inhibition of sodium absorption without a bitter taste. This is the first report showing that 40–50% sodium replacement combined with 3% cellulose encapsulation reduced sodium absorption from sausage by 60% without causing a bitter taste.

Industrial Applications of Selected JFS Articles

Industrial Applications of Selected <i>JFS</i> Articles

Salt microspheres and potassium chloride usage for sodium reduction: Case study with sushi.

The aim of the study was to estimate possibilities of salt substitutes usage in the preparation of two sushi types (nigiri and maki) prepared with different seafood (salmon: Salmo salar, tuna: Thunnus albacares, and shrimp: Pleoticus muelleri). Potassium chloride (Mary samples), Soda-Lo (hollowed microsphere of regular salt crystals), and regular salt (sodium chloride) were used in the experiment. Sushi samples (n = 1960) were evaluated by 40 trained panelists who noticed that maki shrimp samples prepared with Mary salt had higher bitterness (21.48 ± 28.01) in comparison with 2% sodium chloride (7.91 ± 8.80). The saltiness was lower in nigiri tuna prepared with Mary (49.59 ± 17.47) than 2% sodium chloride (61.11 ± 15.75). The study clearly showed the possibility of lowering sodium content in sushi meal with the usage of salt substitutes, with emphasis that Soda-Lo should be considered as a better option due to the retention of sensory properties in sushi samples prepared with this salt substitute.

Increasing Oil Concentration Affects Consumer Perception and Physical Properties of Mayonnaise-type Spreads Containing KCl.

Reducing sodium intakes remains a global challenge for the food industry. KCl is a potential salt substitute but imparts bitterness when used at high concentrations. Little is known about how oil concentrations (OC) affect consumers' perception of saltiness and bitterness in emulsion products such as mayonnaise containing KCl. We evaluated consumers' perception and physical properties of mayonnaise-type spreads at various oil and tastant (NaCl or KCl) concentrations. Consumers (N = 306) evaluated saltiness, bitterness, overall taste liking (OTL) and purchase intent (PI). Viscosity, pH, water activity, and consistency/texture were also measured. Oil and tastant (NaCl or KCl) concentrations had significant effects on saltiness, viscosity, and pH. As OC increased, saltiness intensity slightly decreased for spreads. Increasing oil concentration increased viscosity. Generally, spreads containing KCl had higher bitterness and pH than spreads containing NaCl. All spreads containing KCl were penalized for being "too bitter." PI was affected by OTL for all spreads but OC was also a significant factor in the purchase decision of spreads containing NaCl. This study demonstrated that increasing OC affected consumers' taste perception (saltiness and bitterness) and spreads' physical properties including pH and viscosity.

Volatile and non-volatile compounds in green tea affected in harvesting time and their correlation to consumer preference.

Current study was designed to find out how tea harvesting time affects the volatile and non-volatile compounds profiles of green tea. In addition, correlation of instrumental volatile and non-volatile compounds analyses to consumer perception were analyzed. Overall, earlier harvested green tea had stronger antioxidant capacity (~61.0%) due to the polyphenolic compounds from catechin (23,164mg/L), in comparison to later harvested green teas (11,961mg/L). However, high catechin content in green tea influenced negatively the consumer likings of green tea, due to high bitterness (27.6%) and astringency (13.4%). Volatile compounds drive consumer liking of green tea products were also identified, that included linalool, 2,3-methyl butanal, 2-heptanone, (E,E)-3,5-Octadien-2-one. Finding from current study are useful for green tea industry as it provide the difference in physiochemical properties of green tea harvested at different intervals.

Modification of perceived beer bitterness intensity, character and temporal profile by hop aroma extract

The effect of hop aroma on perceived bitterness intensity, character and temporal profile of beer was investigated. A hop aroma extract was added at 3 levels (0, 245, 490mg/L) to beers at low, medium and high bitterness. Beers were evaluated for perceived bitterness intensity, harshness, roundedness and linger by a trained panel using a rank-rating technique at each bitterness level, with and without nose clips. The use of nose clips enabled the olfactory aspect to be decoupled from taste and mouthfeel aspects of bitterness perception. Results showed significant modification of perceived bitterness in beer by hop aroma depending on the inherent level of bitterness. These modifications were mainly driven by olfaction – in an example of taste-aroma interactions, as well as certain tactile sensations elicited by the hop aroma extract in the oral cavity. At low bitterness, beers with hop aroma added were perceived as more bitter, and of ‘rounded’ bitterness character relative to those without hop aroma. When judges used nose clips, this effect was completely eliminated but the sample was perceived to have a ‘harsh’ bitterness character. Conversely, at high bitterness, even when nose clips were used, judges still perceived beers containing hop aroma to be more bitter. These increases in bitterness perception with nose clips indicates the stimulating of other receptors, e.g. trigeminal receptors by hop aroma extract, which in tandem with the high bitterness, cause perceptual interactions enhancing bitterness intensity and also affecting bitterness character. Bitterness character attributes such as ‘round’ and ‘harsh’ were found to significantly depend on bitterness and aroma levels, with the second level of aroma addition (245mg/L) giving a ‘rounded’ bitterness in low bitterness beers but ‘harsh’ bitterness in high bitterness beers. The impact of aroma on temporal bitterness was also confirmed with time-intensity measurements, and found to be mostly significant at the highest level of hop aroma addition (490mg/L) in low bitterness beers. These findings represent a significant step forward in terms of understanding bitterness flavour perception and the wider impact of hop compounds on sensory perception.

Phenolic compounds of Brazilian beers from different types and styles and application of chemometrics for modeling antioxidant capacity

In the present study we aimed at investigating, for the first time, phenolic compounds in Brazilian beers of different types and styles. We also aimed at applying chemometrics for modeling beer’s antioxidant capacity as a function of their physicochemical attributes (density, refractive index, bitterness and ethanol content). Samples (n=29) were analyzed by PCA originating five groups, especially according to ethanol contents and bitterness. In general, Group V (alcoholic beers with very high bitterness) presented higher refractive index, bitterness, ethanol and phenolics contents than Groups I (non-alcoholic beers) and II (alcoholic beers with low bitterness). Brazilian beers phenolics profile was distinct from that of European beers, with high contents of gallic acid (0.5–14.7mg/L) and low contents of ferulic acid (0.2–1.8mg/L). Using PLS, beer’s antioxidant capacity measured by FRAP assay could be predicted with acceptable precision by data of ethanol content and density, bitterness and refractive index values.

Application of taste sensing system for characterisation of enzymatic hydrolysates from shrimp processing by-products

The objective of this study was to investigate the potential of an instrumental taste-sensing system to distinguish between shrimp processing by-products hydrolysates produced using different proteases and hydrolysis conditions, and the possible association of taste sensor outputs with human gustatory assessment, salt content, and bioactivity. Principal component analysis of taste sensor output data categorised samples according to the proteases used for hydrolysis. High umami sensor outputs were characteristic of bromelain- and Flavourzyme-produced hydrolysates, compared to low saltiness and high bitterness outputs of Alcalase-produced hydrolysates, and high saltiness and low umami outputs of Protamex-produced hydrolysates. Extensively hydrolysed samples showed higher sourness outputs. Saltiness sensor outputs were correlated with conductivity and sodium content, while umami sensor responses were related to gustatory sweetness, bitterness and umami, as well as angiotensin-I converting enzyme inhibitory activity. Further research should explore the dose dependence and sensitivity of each taste sensor to specific amino acids and peptides.

Bitterness values for traditional tonic plants of southern Africa

Ethnopharmacological relevanceBitterness values have been determined for southern African plant species that are traditionally used as tonics (imbizas or ’musa-pelo) to alleviate the symptoms of stress and a variety of ailments related to the digestive system. Aim of the studyTo measure and present, for the first time, the bitterness values of 15 of the best-known and most widely used tonic plants in southern Africa in order to find a rationale for their traditional use in improving appetite and treating digestive ailments. ResultsMost of the plants were found to be very bitter, with bitterness values comparable to those reported for internationally well-known bitter tonics such as Artemisia absynthium L. and Gentiana lutea L. ConclusionsThe relatively high bitterness values obtained for all of the plants indicate that their alleged value in improving digestion and appetite may at least be partly ascribed to the bitter tonic (amarum) effect, i.e., the stimulation of gastric juices via the nervus vagus. It may be interesting to examine the chemical compounds responsible for the bitter taste, as well as the possible links between bitterness and the anecdotal anti-stress properties ascribed to these species.

Effect of vegetable coagulant, microbial coagulant and calf rennet on physicochemical, proteolysis, sensory and texture profiles of fresh goats cheese

In order to determine the technological suitability of vegetable coagulants for the manufacture of cheeses, two different aqueous extracts from cardoon (Cynara cardunculus subsp. flavescens and C. cardunculus subsp. cardunculus) and microbial coagulant (Mucor miehei) were compared with calf rennet. Optical sensors showed that the microbial coagulant had the highest clotting time (T max) whereas both rennet and vegetable coagulants had similar and lower milk clotting times. For most of the physicochemical (Colour CIELab, protein and fat) and textural (cohesiveness and springiness) parameters, no differences were observed between the different enzymes assayed. However, dry matter content, hardness, gumminess and chewiness showed significant differences, higher values being obtained in cheeses made with vegetable coagulants. As regards sensory properties, cheeses made with vegetable coagulants showed less firmness and whiteness but higher bitterness while microbial coagulant and calf rennet showed similar and higher values. No statistically significant differences were found in the soluble nitrogen or non-protein nitrogen fractions between the cheeses. The vegetable coagulants showed higher intensity bands in the Pre-αs-casein region, which was related to higher αs-casein proteolytic rates. The use of vegetable coagulants should enable manufacturers to produce fresh cheeses with new textural features, but to improve sensory profile, different technological strategies might be adopted.

Factors Affecting the Bitterness Intensities of Ten Commercial Formulations of Ambroxol

The bitterness of 10 different products with ambroxol as active ingredient, the original and nine generics, were evaluated by human gustatory sensation tests in which the tablets were kept in the mouth, with water, at 20 and 37°C. The products all showed different bitterness intensities. The original and some of the generic products had comparatively low bitterness intensities but some of the generic products had comparatively high bitterness intensities. The bitterness intensities of these 10 was found to be significantly correlated with both the disintegration time, as evaluated using the ODT-101 (a recently developed apparatus), and the drug concentration in dissolved medium, as measured in a conventional dissolution test. The bitterness threshold of ambroxol solution was found to increase when the temperature of the water with which the tablets were taken, was raised from 20 to 37°C. The equation was calculated to predict the bitterness intensity of ambroxol, a function based on temperature and the ambroxol concentration using data from a standard ambroxol solution at 4, 20 and 37°C. The bitterness intensities obtained for the 10 ambroxol formulations with water at 20 and 37°C, coincided with the bitterness values predicted by the equation.

Sensory Quality of Functional Beverages: Bitterness Perception and Bitter Masking of Olive Leaf Extract Fortified Fruit Smoothies

Olive leaf extract (OLE) contains high amounts of oleuropein and hydroxytyrosol. The antioxidant capacity of these polyphenols makes OLE a promising ingredient for functional food. OLE causes very strong bitterness perception and can therefore only be formulated in low concentrations. In this research, bitter detection and recognition thresholds of OLE-fortified fruit smoothies were determined by a trained sensory panel (n = 11). Masking of the OLE's bitter taste was investigated with addition of sodium cyclamate, sodium chloride, and sucrose by means of a standardized ranking method and a scale test. Detection (5.78 mg/100 g) and recognition thresholds (8.05 mg/100 g) of OLE polyphenols confirmed the low formulation limits when bitterness was not masked by other substances. At higher polyphenol levels of 20 mg/100 g, sodium cyclamate and sucrose were able to reduce bitter taste perception by 39.9% and 24.9%, respectively, whereas sodium chloride could not effectively mask bitterness. Practical Application: Development of functional food poses new challenges for the food industry. A major problem in this field is the high bitterness of natural polyphenol-containing extracts with potential health benefits. This research was conducted to understand the sensory impact of olive leaf extract (OLE), a novel food ingredient with very bitter taste. In product development, the data of this research can be considered for formulation limits and the general sensory quality of OLE-fortified food and beverages.

Instrumental measurement of bitter taste in red wine using an electronic tongue

An electronic tongue (ET) based on potentiometric chemical sensors was assessed as a rapid tool for the quantification of bitterness in red wines. A set of 39 single cultivar Pinotage wines comprising 13 samples with medium to high bitterness was obtained from the producers in West Cape, South Africa. Samples were analysed with respect to a set of routine wine parameters and major phenolic compounds using Fourier transform infrared-multiple internal reflection spectroscopy (WineScan) and high-performance liquid chromatography, respectively. A trained sensory panel assessed the bitterness intensity of 15 wines, 13 of which had a bitter taste of medium to high intensity. Thirty-one wine samples including seven bitter-tasting ones were measured by the ET. Influence of the chemical composition of wine on the occurrence of the bitter taste was evaluated using one-way analysis of variance. It was found that bitter-tasting wines had higher concentrations of phenolic compounds (catechin, epicatechin, gallic and caffeic acids and quercetin) than non-bitter wines. Sensitivity of the sensors of the array to the phenolic compounds related to the bitterness was studied at different pH levels. Sensors displayed sensitivity to all studied compounds at pH 7, but only to quercetin at pH 3.5. Based on these findings, the pH of wine was adjusted to 7 prior to measurements. Calibration models for classification of wine samples according to the presence of the bitter taste and quantification of the bitterness intensity were calculated by partial least squares-discriminant analysis (PLS-DA) regression. Statistical significance of the classification results was confirmed by the permutation test. Both ET and chemical analysis data could discriminate between bitter and control wines with the correct classification rates of 94% and 91%, respectively. Prediction of the bitterness intensity with good accuracy (root mean square error of 2 and mean relative error of 6% in validation) was possible only using ET data.

Taste-masked quinine pamoate tablets for treatment of children with uncomplicated Plasmodium falciparum malaria

Children with uncomplicated malaria are generally treated with oral medication, except those unable to take oral drugs. Even though quinine has shown to be effective in treatment of African children with uncomplicated malaria its high bitterness limited the paediatric use. This study aimed to develop taste-masked quinine tablets suitable for children and offering dosing flexibility to adjust the quinine dose in function of body weight. Methods Insoluble quinine pamoate was used to formulate fast-disintegrating tablets, using a specific tablet design (rectangular tablet which can be divided into 8 subunits) to allow dosing flexibility. The physical properties of tablets were evaluated in vitro, as well as the quinine bioavailability in healthy adults ( n = 18) and the efficacy for treatment of children with uncomplicated Plasmodium falciparum malaria ( n = 56) using a 7-day regimen of 8 mg quinine/kg. Results Quinine pamoate tablets complied with the pharmacopoeial requirements for mass uniformity, friability, content uniformity, breakability, disintegration and dissolution. The quinine pharmacokinetic parameters after single administration of a quinine pamoate tablet were similar to a commercially available quinine sulfate tablet. The fast decline in parasitemia (28.6%/24 h), the reduction rate of fever (all children were apyretic after 72 h) and the steady state quinine plasma concentration (5.7–15.8 μg/ml) proved the efficacy of the quinine pamoate tablets against P. falciparum. Conclusion Fast-dispersible and taste-masked quinine pamoate tablets improved dosing accuracy, allowed easy administration and resulted in a high efficacy during the treatment of children with uncomplicated malaria.

Bitterness in Bacillus proteinase hydrolysates of whey proteins

Whey protein concentrate (WPC) hydrolysates were generated with three commercially available Bacillus proteinase preparations (pH 7.0, 50 °C, 20% (w/v) WPC). Alcalase 2.4L hydrolysates were more bitter than Prolyve 1000 and Corolase 7089 hydrolysates when the proteinase activities were included at equivalent high and low addition levels. A glutamyl endopeptidase (GE) activity present in Alcalase was not detected in the Prolyve and Corolase preparations. Hydrolysate bitterness significantly increased when GE activity was included during Prolyve hydrolysis of WPC, indicating that inclusion of the GE activity was linked with the higher bitterness in Alcalase hydrolysates. A peptide present at higher levels in Prolyve compared to Alcalase hydrolysates was identified by mass spectrometry as β-lactoglobulin f(43–57). Hydrolysis of this peptide by GE was shown to release fragments with increased average hydrophobicity ( Q-value). This may, in part, explain the higher level of bitterness associated with Alcalase compared to Prolyve hydrolysates of WPC.

Triterpenes and triterpenoidal glycosides from the fruits of Ilex paraguariensis (Maté)

A new triterpenoid glycoside, 3b-O-a-L-arabinopyranosyl rotundic acid, named here mateside (4), and the known triterpenes ursolic acid (1), acetylursolic acid (2), 23-hydroxyursolic acid (3), the saponins ziyu-glycoside I (5) and ilexoside II (6), were isolated from fruits of Ilex paraguariensis. Their structures were established on the basis of 1D and 2D NMR spectroscopic methods. The threshold bitterness values for mateside and ilexoside II were also determined and compared with saponins obtained from leaves of I. paraguariensis and other Ilex species. The high bitterness of Ilexoside II, one of the main saponins found the fruits, but not in the leaves of I. paraguariensis, suggests that the utilization of the fruits in the Maté production can produce a strong taste variation and unknown physiological effects.

Composition and Sensory Qualities of Wines Prepared from White Grapes by Fermentation with and without Grape Solids

Wines were prepared from seven harvests representing six white grape varieties. The must of each harvest was divided into 3 or 5 equivalent lots. Lots were fermented dry at 16 C from juice clarified by settling, from turbid juice with double the normal amount of suspended solids, and from the entire destemmed, crushed grape mass inoculated with yeast and maintained in contact with the pomace for 24, 48, or 120 hours. The expert panel of tasters judged wines prepared from clarified juice to be much higher in quality and desirable aroma than any of the other wines. Chemical analyses were essentially identical for the wines prepared from clarified juice or turbid juice, but the wines from turbid juice were much lower in quality and considered harsher (higher ratings for astringency and bitterness). The major quality difference between wines from these two treatments was due to the fresh, clean, delicate, fruity, characteristic odor called fermentation bouquet in wines from the clarified samples and its decrease or absence, plus off odors (particularly hydrogen sulfide) in wines from the turbid samples. The wines with increasing pomace contact exhibited increasing total phenol content coupled with increasing astringency rating. Pomace contact sufficient to give additional total phenol (as gallic acid) of about 100 mg/L from grape solids of seeded white grapes gave just recognizably increased astringency in white table wines. The wines with up to 5 days of pomace contact during fermentation at low temperature did not resemble red wines in flavor or odor, but remained similar to normal dry white wines, although with generally lower quality. Bitterness ratings did not parallel astringency or phenol content, and there appeared to be higher bitterness in intermediate levels of pomace contact and phenol content.

Composition and Sensory Qualities of Wines Prepared from White Grapes by Fermentation with and without Grape Solids

Wines were prepared from seven harvests representing six white grape varieties. The must of each harvest was divided into 3 or 5 equivalent lots. Lots were fermented dry at 16 C from juice clarified by settling, from turbid juice with double the normal amount of suspended solids, and from the entire destemmed, crushed grape mass inoculated with yeast and maintained in contact with the pomace for 24, 48, or 120 hours. The expert panel of tasters judged wines prepared from clarified juice to be much higher in quality and desirable aroma than any of the other wines. Chemical analyses were essentially identical for the wines prepared from clarified juice or turbid juice, but the wines from turbid juice were much lower in quality and considered harsher (higher ratings for astringency and bitterness). The major quality difference between wines from these two treatments was due to the fresh, clean, delicate, fruity, characteristic odor called fermentation bouquet in wines from the clarified samples and its decrease or absence, plus off odors (particularly hydrogen sulfide) in wines from the turbid samples. The wines with increasing pomace contact exhibited increasing total phenol content coupled with increasing astringency rating. Pomace contact sufficient to give additional total phenol (as gallic acid) of about 100 mg/L from grape solids of seeded white grapes gave just recognizably increased astringency in white table wines. The wines with up to 5 days of pomace contact during fermentation at low temperature did not resemble red wines in flavor or odor, but remained similar to normal dry white wines, although with generally lower quality. Bitterness ratings did not parallel astringency or phenol content, and there appeared to be higher bitterness in intermediate levels of pomace contact and phenol content.