Molecular mechanisms of bitterness and astringency in the oral cavity induced by soyasaponin

The interaction mechanism between soyasaponin(Ssa)and bitter receptors/mucin,as well as the saliva interface behavior of Ssa,were investigated to explore the presentation mechanism of Ssa bitterness and astringency(BA).Strong bitterness arising from high Ssa concentrations(0.5–1.5 mg/mL)had a masking effect on astringency.At Ssa concentrations of 1.0–1.5 mg/mL,Ssa micelles altered the structure of mucin,exposing its internal tryptophan to a more polar environment.At Ssa concentrations of 0.05–1.50 mg/mL,its reaction with mucin increased the aggregation of particles in artificial saliva,which reduced the frictional lubricating properties of oral saliva.Ssa-mucin interactions affected the salivary interfacial adsorption layer,and their complexes synergistically reduced the interfacial tension.Ssa monomers and soyasapogenols bind to bitter receptors/mucin via hydrogen bonding and hydrophobic interactions.Class A Ssa binds more strongly than class B Ssa,and thus likely presents a higher BA.In conclusion,Ssa interacts with bitter receptors/mucin causing conformational changes and aggregation of salivary mucin,resulting in diminished frictional lubricating properties of oral saliva.This,in turn,affects taste perception and gustatory transmission.

Effects of Carbon Dioxide on Astringency Removal in Mopanshi Persimmon

Fruits of persimmon (Diospyros kaki cv. Mopanshi) were used to investigate the effects of different concentrations of carbon dioxide (CO 2) gas on removing astringency after harvest. Treatment of 95% concentration of CO 2 gas gave the best results; fruits turned non-astringent after 20 h, and kept the fruit firm for 7 d at room temperature. Fruits, treated with 85 and 90% concentration of CO 2 gas, turned non-astringent after 2428 h, and the firmness-keeping stage was 56 d at room temperature. While the CO 2 gas was at 80, 70 and 60%, the de-astringency period was 48, 72 and 96 h, and the corresponding firmness-keeping stage was 3, 2 and 1 d, respectively. Fruits, treated with 50% concentration of CO 2 gas, remained astringent.

Screening Germplasm Resources of Tea Plant with Less Bitterness and Astringency Index

The aim of this study was to identify tea varieties with less bitterness and astringency index that could be used as important sources for breeding and in the production of high quality tea. We studied 36 cultivars or lines which had been preserved in Tea Germplasm Garden of Fujian. The contents of catechins in spring tea shoots, summer tea shoots and autumn tea shoots in 36 varieties and lines were analyzed by HPLC. Analysis of these tea varieties and lines revealed that the catechins contained in the tea shoots in different seasons are highly variable. The content of ester-catechins in spring and summer tea shoots was higher than that of autumn, while non-ester-catechins did not showed the same characteristic. The content of EGCG showed an extremely significant positive correlation with T1 （T1 = EGC ＋ EGCG ＋ GCG ＋ EGC）, an extremely significant negative correlation with DL-C, the content of EGC showed the same characteristic. Among them, 10 cultivars with less bitterness and astringency index （the annual average bitterness and astringency index 〈 8.0） were considered good candidates as important breeding materials tbr tea infusion quality improvement.

A tribo-chemical view on astringency of plant-based food substances

Consumption of plant-based food products having high composition of polyphenols leads to the sensation of astringency.For sliding oral surfaces,friction is an essential property during the oral perception of roughness and dryness which are attributes associated with astringency.Different factors including the chemical composition of interacting layers,structure and operation of interfaces have an effect on the astringency development process.The manner of interactions occurring at oral interfaces suggest there is a system dependence of astringency and highlights the importance of adopting a tribosystems approach.Available measurement techniques have shown an existing relationship between salivary protein-polyphenol interaction and an astringent mouthfeel.Nevertheless,the tribo-chemistry involved in this multifaceted sensation remains largely unexplored in a comprehensive manner.In this review the underlying tribo-chemical processes useful in understanding the mechanism of astringency are highlighted and discussed considering current techniques employed to investigate astringency perception.Loss of lubrication on oral surfaces owing to the tribo-chemical interactions involving saliva and astringent plant proteins requires subsequent deformations of oral tissues which are significant enough to induce strains at mechanoreceptor locations,leading to the sensation of astringency.It is proposed that micro-scale contact modelling on the interaction of food particles/aggregates,boundary layers and oral surfaces shows potential in addressing the knowledge gap between tribo-chemical measurement techniques and panel tests,making it possible to attain a predictor for astringency.

Preferential transport activity of Dk DTX5/MATE5 affects the formation of different astringency in persimmon

Proanthocyanidins(PAs) are specialized metabolites that infuence persimmon fruit quality.Normal astringent(A)-type and non-astringent(NA)-type mutants show significant variation in PA accumulation, but the infuencing mechanism remains unclear. In this study, among the six identified DTXs/MATEs proteins associated with PA accumulation, we observed that allelic variation and preferential transport by Dk DTX5/MATE5 induced variation in PA accumulation for A-type and NA-type fruit. The expression pattern of Dk DTX5/MATE5 was correlated with PA accumulation in NA-type fruit. Upregulation and downregulation of Dk DTX5/MATE5 promoted and inhibited PA accumulation, respectively, in the NA-type fruit. Interestingly, transporter assays of Xenopus laevis oocytes indicated that Dk DTX5/MATE5 preferentially transported the PA precursors catechin, epicatechin, and epicatechin gallate, resulting in their increased ratios relative to the total PAs, which was the main source of variation in PA accumulation between the A-type and NA-type. The allele lacking Ser-84 in Dk DTX5/MATE5 was identified as a dominantly expressed gene in the A-type and lost its transport function. Site-directed mutagenesis revealed that Dk DTX5/MATE5 binds to PA precursors via Ser-84. These findings clarify the association between the transporter function of Dk DTX5/MATE5 and PA variation, and can contribute to the breeding of new cultivars with improved fruit quality.

A novel technology to reduce astringency of tea polyphenols extract and its mechanism

Objective:Tea polyphenols are natural extracts used widely throughout the world.However,the severe astringency of tea polyphenols has reduced patient compliance.Based on the analysis of the formation mechanism of astringency,this paper hopes to propose a new method to control the astringency of tea polyphenols and improve patient compliance without changing its effect.Methods:Artificial saliva was used to prepare the tea polyphenols solution with different p H,using bcasein to imitate salivary protein,and preparing 1.2 mg/m L b-casein solution.A fluorescence quenching test was used to study the interaction between tea polyphenols and b-casein,combined with the stability test results of the compound,we can choose the p H with weak binding but good stability as the best p H for masking astringency.The taste-masking tablets were prepared under the best p H conditions,and the Xinnaojian Original Tablets were prepared according to the conventional preparation method.The disintegration time limit and solubility were tested respectively.The astringency of Xinnaojian original tablets and taste-masking tablets was evaluated by visual analogue scale(VAS).Results:The result of the fluorescence quenching test prompted that the combination force was the weakest when the p H was 4.9.Further synchronous fluorescence analysis showed that an increase in p H resulted in a decrease of the binding sites between tea polyphenols and b-casein,and this decrease was closely related to changes in tryptophan residues in b-casein.Both original and taste-masking Xinnaojian Tablets were prepared.Volunteers’VAS scores illustrated that the astringency improved significantly with the masking tablets(P<0.05).Conclusion:This p H-adjusting masking treatment had little effect on the recovery of polyphenols from the tablets or the dissolution of the tablets.This study provides a novel and feasible astringency masking technology for tea polyphenols and its preparation.

Theory and Properties of Atomic Spacetime

Following A. Einsteins aspirations for an atomic theory, a novel theory of spacetime quantization/atomization based on finite Atomic AString Functions evolving since the 1970s is offered. Atomization Theorems allow representing polynomials, analytic functions, and solutions of General Relativity via the superposition of solitonic atoms which can be associated with flexible spacetime quanta, metriants, or elementary distortions. With multiple interpretations discussed, discrete-continuous spacetime is conceptualized as a lattice network of flexible solitonic atoms adjusting locations to reproduce different metrics. The theory may offer some variants of unified field theory under research based on Atomic AString Function where, like in string theory, fields become interconnected having a common mathematical ancestor.

Atomization Theorems in Mathematical Physics and General Relativity

Formulated Atomization Theorems extend the theory of Atomic AString Functions evolving since the 1970s allowing representation of polynomials, complex analytic functions, and solutions of linear and nonlinear differential equations via Atomic Series over smooth finite Atomic Splines. Noting the preservation of analyticity for Ricci and Einstein tensors, special new theorems are formulated for General Relativity representing spacetime field via superpositions of flexible finite “solitonic atoms” resembling quanta. The novel Atomic Spacetime model correlates with A. Einstein’s 1933 paper predicting a new “atomic theory”. The theorems can be applied to many theories of mathematical physics, elasticity, hydrodynamics, soliton, and field theories for unified representation of fields via series over finite Atomic AString Functions which may offer a unified theory under research where fields are connected with a common mathematical ancestor.

Hydrodynamic Analysis and Shape Optimization for Vertical Axisymmetric Wave Energy Converters

The absorber is known to be vertical axisymmetric for a single-point wave energy converter （WEC）. The shape of the wetted surface usually has a great influence on the absorber＇s hydrodynamic characteristics which are closely linked with the wave power conversion ability. For complex wetted surface, the hydrodynamic coefficients have been predicted traditionally by hydrodynamic software based on the BEM. However, for a systematic study of various parameters and geometries, they are too multifarious to generate so many models and data grids. This paper examines a semi-analytical method of decomposing the complex axisyrnmetric boundary into several ring-shaped and stepped surfaces based on the boundary discretization method （BDM） which overcomes the previous difficulties. In such case, by using the linear wave theory based on eigenfunction expansion matching method, the expressions of velocity potential in each domain, the added mass, radiation damping and wave excitation forces of the oscillating absorbers are obtained. The good astringency of the hydrodynamic coefficients and wave forces are obtained for various geometries when the discrete number reaches a certain value. The captured wave power for a same given draught and displacement for various geometries are calculated and compared. Numerical results show that the geometrical shape has great effect on the wave conversion performance of the absorber. For absorbers with the same outer radius and draught or displacement, the cylindrical type shows fantastic wave energy conversion ability at some given frequencies, while in the random sea wave, the parabolic and conical ones have better stabilization and applicability in wave power conversion.

A Preliminary Study on the Theory of Polar Coordinates Digital Photogrammetry and the Coordinate System of Spatial Information

The development of new aeronautics and astronautics technologies has been constrained by strict mathematical rules for data processing among the diverse methods used to obtain spatial information.The acquisition of spatial information has been affected by various choices including the applied technologies(e.g.,push broom sensors),techniques(e.g.,zoom imaging),and equipment settings(e.g.,swing angle,aerial platform attitude,camera angle)in terms of the convergence,efficiency,and accuracy of the data.Based on the principle of the bionic machine parallax angle and pyramidal projection of the aerial space platform to the surface,this study explored solutions for high-resolution image sparsity,ill-conditioned singularity,and non-convergence by building a set of mathematical models to process the polar coordinates of the parallax angular vector.This study also formed a polar information theory for initial spatial information.This method improved the ranges of accuracy,efficiency,and anti-interference in close-range photogrammetry and the free net bundle adjustment model by several orders of magnitude.The open source code was made globally available more than 3 years ago,and has received positive reactions.The method’s effectiveness was verified using aerophotogrammetry and absolute network adjustment model experiments,and its performance was better than that of the Cartesian coordinate processing method.Finally,the higher-order solution characteristics of various applications and spaceflight platforms were provided,which are expected to provide a foundation for construction of a new polar coordinate system for aerospace multi-scale all-attitude spatial information acquisition,organization,management,storage,processing,and application.

Atomic Spacetime Model Based on Atomic AString Functions

A novel model of spacetime and fields atomization based on Atomic Series over finite Atomic AString Functions is offered. Formulated Atomization Theorems allow representing polynomials, analytic functions, and solutions of field equations including General Relativity via superposition of solitonic atoms which can be associated with flexible spacetime quantum, metriants, or elementary distortions. Spacetime is conceptualized as a lattice of flexible Atomic Solitons adjusting locations to reproduce different metrics and other physical fields. It may offer the variants of unified field theory based on Atomic Solitons where, like in string theory, fields become interconnected having a common mathematical ancestor.

Therapy of Suppressing Yang and Astringing Yin for the Treatment of Cancer-Related Insomnia

The pathogenesis of can cer-related in som nia(CRI)mainly in eludes,first,the flow of cancerous toxin leading to the disorder of visceral qi;second,cancer-related radiotherapy and chemotherapy belonging to"exogenous pathogenic factors"to a certain extent,which can further aggravate visceral disorders.The therapeutic principle of Chinese medicine is to tranquilize the mind on the basis of regulating viscera,suppressing yang,and astringing yin.On this theoretical basis,Professor Zheng Yuling created a representative prescription of Zhenjing Anshen Granules(镇静安神颗粒)which can achieve the co-regulation of the heart,liver,and kidney,tranquilizing the mind and nourishing the blood.Clinically,the selection of prescriptions and medicines needs to be considered due to factors such as different treatment stages and differ-ences in patients'constitutions.