Astringency and its sub-qualities: a review of astringency mechanisms and methods for measuring saliva lubrication.

Astringency is an important mouthfeel attribute that influences the sensory experiences of many food and beverage products. While salivary lubricity loss and increased oral friction were previously believed to be the only astringency mechanisms, recent research has demonstrated that nontactile oral receptors can trigger astringency by responding to astringents without mechanical stimulation. Various human factors have also been identified that affect individual responses to astringents. This article presents a critical review of the key research milestones contributing to the current understanding of astringency mechanisms and the instrumental approaches used to quantify perceived astringency intensity. Although various chemical assays or physical measures mimic in-mouth processes involved in astringent mouthfeel, this review highlights how one chemical or physical approach can only provide a single measure of astringency determined by a specific mechanism. Subsequently, using a single measurement to predict astringency perception is overly idealistic. Astringency has not been quantified beyond the loss of saliva lubrication; therefore, nontactile receptor-based responses must also be explored. An important question remains about whether astringency is a single perception or involves distinct sub-qualities such as pucker, drying, and roughness. Although these sub-quality lexicons have been frequently cited, most studies currently view astringency as a single perception rather than dividing it into sub-qualities and investigating the potentially independent mechanisms of each. Addressing these knowledge gaps should be an important priority for future research.

Characterization of chemical and sensory properties of Cabernet Sauvignon and Marselan wines made by flash détente technique.

This study aimed to characterize the sensory profiles of wines produced using the flash détente (FD) technique and to identify the flavor compounds contributing to the sensory characteristics. The FD technique was applied to two major grape varieties, Cabernet Sauvignon and Marselan, from the Changli region of China to produce high-quality wines with aging potential. Compared to the traditional macerated wines, the FD wines showed greater color intensity, mainly due to the higher levels of anthocyanins. Regarding the aroma characteristics, FD wines were found to have a more pronounced fruitness, especially fresh fruit note, which was due to the contribution of higher concentration of esters. Concurrently, FD wines showed an increased sweet note which was associated with increased lactones and furanones. In addition, FD wines exhibited reduced green and floral notes due to lower levels of C6 alcohols and C13-norisoprenoids. With regard to mouthfeel, FD wines presented greater astringency and bitterness, which was due to the higher levels of phenolics. The total concentration of condensed tannins and condensed tannins for each degree of polymerization was considerably higher in FD wines due to the strong extraction of the FD technique. A significant increase in grape-derived polysaccharides and glycerol was also found in FD wines, contributing to a fuller body. This study contributed to an increase in the knowledge of the Changli region and demonstrated that the FD technique could be applied to the wine production in this region to address the negative impacts of rainfall in individual vintages.

Oral Astringency in Plant Proteins: An Underestimated Issue in Formulating Next-Generation Plant-Based Foods.

Ensuring the supply of affordable, palatable, healthy, and sustainable nutrients to feed the growing population without transgressing the planetary boundaries remains a key challenge in the food science community. A dietary transition toward low-emission, plant-based foods, with less reliance on animal agriculture, is advocated for sustainability, health, and ethical reasons. A major hurdle for mainstream adoption of plant-based foods is their poor sensorial performance, such as nonjuicy and astringent textures as well as various off-flavors. This review presents the current understanding of astringency and oral friction of plant-based foods. It focuses on plant proteins and their application in plant-based meat and dairy analogs. In addition, the latest advances in the quantitative characterization of astringency using tribology, electrochemistry, and cellular tools are covered. Finally, we examine factors influencing astringency and propose easy-to-implement colloidal strategies that may mitigate astringency issues, thereby underpinning the design of the next generation of sustainable and pleasurable plant-based foods.

Influence of taste sensitivity on preference and sensory perception of mezcal.

The perception of orosensory stimuli, which includes flavor, can vary between individuals. These individual variations in oral sensations can be due to genetic factors and it would appear that they can predict food liking and consumption. The most studied source of variation is related to bitter taste perception associated with 6-n-propylthiouracil (PROP) responsiveness. In this context, humans can be classified as non-tasters (NT), medium tasters (MT) and supertasters (ST). Evidence suggests that genetic variation in bitter taste perception contributes to differences in the level of irritation caused by alcohol perception in solutions. The aim of this investigation was to study the bitter taste sensitivity among a group of mezcal consumers and its relationship with sensory perception and preference through PROP taster status. The tests were carried out in the state of Oaxaca in Mexico. A total of 83 mezcal consumers were classified by their PROP taster status and were asked to provide sensory descriptors for five mezcal samples and rate them according to the level of liking. The three-solution test was used to classify the subjects as NT, MT, and ST, while a Multiple Factor Analysis (MFA) was used to visualize the sensory descriptors provided by these three groups. The proportion of MT subjects was 16%, while the proportion of NT and ST was 34 and 51%, respectively. The MT provided higher liking ratings for at least three mezcal samples. According to MFA, the mezcal samples were organized in a similar configuration along the two dimensions. However, NT mentioned a limited number of simple terms (strong flavor, tasteless, burning in the mouth) to describe the samples, whereas ST used a more complex vocabulary (astringent, smoky, scratchy aftertaste). These data suggest that the preference for mezcal samples was similar for non-taster and supertasters, but there are indications that the sensory perception of mezcal differs between groups.

Sensory Nutrition and Bitterness and Astringency of Polyphenols.

Recent studies have demonstrated that the interaction of dietary constituents with taste and olfactory receptors and nociceptors expressed in the oral cavity, nasal cavity and gastrointestinal tract regulate homeostasis through activation of the neuroendocrine system. Polyphenols, of which 8000 have been identified to date, represent the greatest diversity of secondary metabolites in plants, most of which are bitter and some of them astringent. Epidemiological studies have shown that polyphenol intake contributes to maintaining and improving cardiovascular, cognitive and sensory health. However, because polyphenols have very low bioavailability, the mechanisms of their beneficial effects are unknown. In this review, we focused on the taste of polyphenols from the perspective of sensory nutrition, summarized the results of previous studies on their relationship with bioregulation and discussed their future potential.

In Situ Oral Metabolism Analysis of Astringent Compounds in Tea by Paper Spray Mass Spectrometry, Electrospray Mass Spectrometry, Turbidimetry, and Sensory Evaluation.

The phenolic compounds (PCs) are the primary components responsible for the astringency of tea infusions, and this astringency is intricately linked to the in situ oral metabolism of PCs in saliva. Initially, a total of 54 PCs were identified in tea infusions by electrospray mass spectrometry (ESI-MS). Subsequently, an in vivo metabolism analysis of PCs during varying drinking times and oral locations was conducted by both paper spray mass spectrometry (PS-MS) and sensory evaluation. The metabolism of PCs within oral saliva was a prolonged process, the residual PCs were distributed across diverse oral regions after drinking tea infusion, and the higher residual PC content reflected the stronger astringency intensity. Furthermore, an in vitro metabolism analysis of PCs under varied reaction temperatures and durations was performed by ESI-MS and turbidimetry. As the reaction time extended, more PCs in tea was interacting with saliva. Moreover, the higher temperatures facilitated this interaction between PCs and saliva. Therefore, this investigation establishes a foundation for further elucidating the mechanisms underlying astringency formation.

Wine tannins and their aggregation/release with lipids and proteins: Review and perspectives for neurodegenerative diseases.

Tannins are amphiphilic molecules, often polymeric, which can be generally described as a core containing hydrophobic aromatic rings surrounded by hydroxyl groups. They have been known for millennia and are part of human culture. They are ubiquitous in nature and are best known in the context of wine and tea tasting and food cultures. However, they are also very useful for human health, as they are powerful antioxidants capable of combating the constant aggressions of everyday life. However, their mode of action is only just beginning to be understood. This review, using physicochemical concepts, attempts to summarize current knowledge and present an integrated view of the complex relationship between tannins, proteins and lipids, in the context of wine drinking while eating. There are many thermodynamic equilibria governing the interactions between tannins, saliva proteins, lipid droplets in food, membranes and the taste receptors embedded in them. Taste sensations can be explained using these multiple equilibria: for example, astringency (dry mouth) can be explained by the strong binding of tannin micelles to the proline-rich proteins of saliva, suppressing their lubricating action on the palate. In the presence of lipid droplets in food, the equilibrium is shifted towards tannin-lipid complexes, a situation that reduces the astringency perceived when consuming a tannic wine with fatty foods, the so-called "camembert effect". Tannins bind preferentially to taste receptors located in mouth membranes, but can also fluidify lipids in the non-keratinized mucous membranes of the mouth, which can impair the functioning of taste receptors there. Cholesterol, present in large quantities in keratinized mucous membranes, stiffens them and thus prevents tannins from disrupting the conduction of information through other taste receptors. As tannins assemble and disassemble depending on whether they are in contact with proteins, lipids or taste receptors, a perspective on their potential use in the context of neurodegenerative diseases where fibrillation is a key phenomenon will also be discussed.

Impact of thermal treatment on proanthocyanidin-pectin binary complexes: Insights from structural, rheological, antioxidant, and astringent properties.

In this study, the effects of thermal treatments on the structural, rheological, water mobility, antioxidant, and astringency properties of proanthocyanidin (PA)-pectin binary complexes were investigated. Thermal treatments (25, 63, or 85 °C) significantly decreased the particle size but increased the molecular weight of PA-pectin complexes, which indicated that heating altered the intermolecular and intramolecular interactions between PA and pectin. The thermal treatments reduced the apparent viscosity of both pectin and PA-pectin complexes, but the presence of proanthocyanidins (PAs) increased the apparent viscosity and water mobility of the PA-pectin complexes. Antioxidant activity analysis showed that the presence of pectin slightly reduced the antioxidant activity of the PAs, but there were no significant changes in the total phenolic content and antioxidant activity after thermal treatment. Finally, we found that pectin reduced the astringency of the PAs by forming PA-pectin complexes. Moreover, the thermal treatments also significantly reduced the astringency of the PA-pectin complexes.

Study on the mechanism of natural polysaccharides on the deastringent effect of Triphala extract.

This present study investigated the masking effect of high methoxyl pectin, xanthan gum, and gum Arabic on the astringency of the traditional herbal formula Triphala and further examined the mechanism of polysaccharide reducing astringency. Results of sensory evaluation and electronic tongue illustrated that 0.6 % pectin, 0.3 % xanthan gum, and 2 % gum Arabic had a substantial deastringent effect. The polyphenols in Triphala are basically hydrolysable tannins, which with high degree of gallic acylation may be the main astringent component of Triphala. Moreover, the three polysaccharides can combine with ß-casein through CO and NH groups to form soluble binary complexes and decrease the secondary structure of ß-casein. When polysaccharides were added to the Triphala-protein system, polyphenol-protein precipitation was also diminished, and they were capable of forming soluble ternary complexes. Consequently, the competition between polysaccharides and polyphenols for binding salivary proteins and the formation of ternary complexes help decrease the astringency of Triphala.

Different physicochemical interactions between varietal wines and human saliva: Correspondence with astringency.

Astringency corresponds to the sensation of dryness and roughness that is experienced in the oral cavity in association with the interaction between salivary proteins and food polyphenols. In this study, the phenolic composition of seven varietal wines, the intensity of astringency they evoke and the physicochemical reactivity of these wines with whole human saliva were evaluated. Phenolic composition of wines was characterized by spectrophotometry and HPLC chromatography. Intensity of astringency was evaluated by trained sensory panels. Saliva from a single volunteer subject was used to assess wine-saliva interactions. To this end, binary mixtures were produced at different v/v wine/saliva ratios and each of them assayed for the ability of the salivary protein to diffuse on a cellulose membrane (diffusion test) and to remain in solution (precipitation test). Physicochemical reactivities between wine components and the protein fraction of saliva were contrasted against the astringency and the phenolic profile of each varietal wine. The study supports the view that astringency depends on physicochemical interactions between two complex matrices -wine and saliva- and not between some of their particular components.

Study on the evaluation method of cigarette astringency in the simulated oral environment.

Cigarettes with pronounced astringency can diminish consumers' enjoyment. However, due to the complex composition of cigarettes, quantifying astringency intensity accurately has been challenging. To address this, research was conducted to develop a method for assessing astringency intensity in a simulated oral environment. The astringency intensity of four cigarette brands was determined using the standard sensory evaluation method. The mainstream smoke absorbing solution (MS) was prepared by simulating the cigarette smoking process, and its physicochemical properties (such as total phenol content and pH levels) were analyzed. The lubrication properties of the five solutions were tested using the MFT-5000 wear tester, and factors influencing cigarette astringency were examined. The findings showed that total phenol content and pH of MS were positively and negatively correlated with astringency intensity, respectively. Particularly, the lubrication properties of MS were significantly correlated with astringency intensity, and the correlation coefficient was affected by load and speed during testing. The study concluded that coefficient of friction was a more reliable measure for assessing the extent of astringency in cigarettes than the total phenol content and pH of MS, offering new insights into astringency evaluation and development of high-grade cigarettes.

Integrated Transcriptomic and Proteomic Analysis Identifies Novel Regulatory Genes Associated with Plant Growth Regulator-Induced Astringency in Grape Berries.

Astringency influences the sensory characteristics and flavor quality of table grapes. We tested the astringency sensory attributes of berries and investigated the concentration of flavan-3-ols/proanthocyanidins (PAs) in skins after the application of the plant growth regulators CPPU and GA3 to the flowers and young berries of the "Summer Black" grape. Our results showed that CPPU and GA3 applications increase sensory astringency perception scores and flavan-3-ol/proanthocyanidin concentrations. Using integrated transcriptomic and proteomic analysis, differentially expressed transcripts and proteins associated with growth regulator treatment were identified, including those for flavonoid biosynthesis that contribute to the changes in sensory astringency levels. Transient overexpression of candidate astringency-related regulatory genes in grape leaves revealed that VvWRKY71, in combination with VvMYBPA1 and VvMYC1, could promote the biosynthesis of proanthocyanidins, while overexpression of VvNAC83 reduced the accumulation of proanthocyanidins. However, in transient promoter studies in Nicotiana benthamiana, VvWRKY71 repressed the promoter of VvMYBPA2, while VvNAC83 had no significant effect on the promoter activity of four PA-related genes, and VvMYBPA1 was shown to activate its own promoter. This study provides new insights into the molecular mechanisms of sensory astringency formation induced by plant growth regulators in grape berries.

Zinc sulphate administered by transdermal iontophoresis improves breaking strength of surgical wounds in skin of alloxan-induced diabetic rats

PURPOSE:To investigate the effect of zinc sulphate administered by transdermal iontophoresis (TDI) on mechanical resistance of surgical wounds performed in the skin of diabetic rats. METHODS:One hundred and sixty male Wistar rats weighing approximately 250g were submitted to an incision surgery at the anterior region of abdomen and randomly distributed into four experimental groups with 40 non-diabetic control animals (G1) and 40 untreated diabetic animals (G2), both without any treatment of incisions; 40 non-diabetic animals (G3) and 40 untreated diabetic animals (G4), both with incisions treated with zinc sulphate, administered for a period of four consecutive days after surgery, in sessions of ten minutes duration, using a continuous-current electrostimulator (Zn + TDI). Each experimental group was further divided into four subgroups with ten rats each to be evaluated on the 4th, 7th, 14th, and 21st day after surgery. In each period were analyzed clinical and laboratory from the animals, and measured the breaking strength and hydroxyproline content (OH-P) of the skin scars. RESULTS: Breaking strength (BS) was significantly reduced (p<0.05) in skin scars of untreated diabetic rats (G2) on the 7th, 14th, and 21st postoperative days when compared to non-diabetic control rats (G1). In contrast, BS in skin scars of non-diabetic and untreated diabetic rats (G3, G4) treated with Zn + TDI showed significant increase (p<0.05) in those periods when compared with their respective controls with untreated incisions. The OH-P content of the scars did not show statistically significant variation in all studied groups at four different times evaluated after surgery. CONCLUSIONS: Zinc sulphate administered by transdermal iontophoresis had beneficial effect on the mechanical resistance of scars produced in the skin of diabetic rats. This therapeutic may have potential to reduce the complications observed in surgical wounds of the skin in diabetic subjects, mainly in most vulnerable stages of incisions to dehiscences, leakages and infections.

The effects of ingested aluminium on brain cytochrome oxidase activity / Efectos de la ingestión de aluminio sobre la actividad de la oxidasa citocrómica del cerebro

Aluminium has a unique combination of physical and chemical properties which has enabled man to put this metal to very wide and varied use. However, prolonged exposure to aluminium ions may lead to adverse health effects. In this study, we evaluated the effects of dietary aluminium on the protein composition and the intrinsic activity of cytochrome oxidase (COX) for brain mitochondria. New Zealand white rabbits were maintained on a diet of commercial rabbit pellets and distilled water for a period of 12 weeks. For the experimental group, AlCl3, 330mg/kg/L was added to the drinking water. When compared to the control, mitochondria isolated from the brains of the AlCl3 fed rabbits showed no change in Km but an approximate 35% decrease in both the low and high affinity Vmax values. Also, whereas the protein composition of the mitochondria from both sources appeared to be normal, isolation of highly purified COX proved to be difficult and for the AICI3 fed rabbits, a number of the enzyme's low molecular weight subunits were absent. These results appear to confirm a relationship between long term aluminium consumption and low brain COX activity; they further suggest that an altered COX structure may be the cause of the low enzymic activity.

El aluminio posee una combinación única de las propiedades físicas y químicas que ha permitido al ser humano hacer un uso amplio y variado de este metal. Sin embargo, un número de estudios recientes, sugiere que la exposición prolongada a los iones de aluminio puede tener efectos nocivos sobre la salud. En el presente estudio, evaluamos los efectos del aluminio dietético sobre la composición proteínica y la actividad intrínseca de la oxidasa citocrómica (COX) para la mitocondria cerebral. Conejos blancos de Nueva Zelanda, fueron mantenidos con una dieta de alimento para conejos y agua destilada por un período de 12 semanas. Para el grupo experimental AlCl3, 330mg/kg/L fueron añadidos al agua potable. En comparación con el grupo de control, las mitocondrias aisladas de los cerebros de los conejos alimentados con AlCl3 no mostraron cambios en Km pero hubo una disminución de aproximadamente 35% tanto en los valores Vmax de baja y alta afinidad. Por otro lado, mientras que la composición proteica de las mitocondrias de ambas fuentes parecía ser normal, resultó difícil aislar el COX altamente purificado y un número de enzimas de subunidades de bajo peso molecular MMMM estuvieron ausentes. Estos resultados parecen confirmar una relación entre el consumo de aluminio a largo plazo y la baja actividad del COX del cerebro. Asimismo, sugieren que una alteración de la estructura del COX puede ser la causa de una baja actividad enzimática.

TeleCondutas: hemorroidas / TeleGuides: hemorrhoids

Hemorroidas são coxins vasculares normais do canal anal. São formados por espaços vasculares (sinusoides), tecido elástico e conjuntivo, e músculo liso. Sua função é proteger os esfíncteres anais subjacentes e contribuir para a continência fecal. Reservamos o termo "doença hemorroidária" para quando existem sintomas relacionados à sua presença. É mais prevalente em pessoas com idade entre 45 e 65 anos, tendo como principal causa o esforço evacuatório repetitivo, que determina o estiramento do tecido de sustentação dos plexos. Constipação, esforço evacuatório prolongado e gestação são seus principais fatores de risco. Esta guia apresenta informação que orienta a conduta para casos de hemorroidas no contexto da Atenção Primária à Saúde, incluindo: classificação das hemorroidas, sinais e sintomas, diagnóstico, tratamento da doença hemorroidária na APS, tratamento no serviço especializado, indicação de colonoscopia e encaminhamento para serviço especializado.

Aplicaçäo do Subgalato de Bismuto como Hemostático em Cirurgia Periodontal / Use of Bismuth Subgallate as a hemostatic agent in Periodontal Surgery

A necessidade de um método ou substância eficaz para homostasia e a observaçäo do uso de hemostáticos compatíveis na Medicina, levou ao conhecimento de um produto conhecido como Subgalato de Bismuto. O uso específico deste material como adstringente na hemostasia foi descrito na Otorrinolaringologia na década de 60 e atualmente tem sido utilizado também em Odontologia, especificamente em cirurgias periodontais que resultem em exposiçäo do tecido conjuntivo, com resultados clínicos favoráveis

Saccharomyces cerevisiae Hansen CBS 5926 en pacientes pediatricos multitratados con diarrea aguda / Saccharomyces cerevisiae Hansen CBS 5926 in pediatric multitreated patients with acute diarrhea

Cuarenta y cuatro niños con diarrea aguda fueron tratados con Saccharomyces Cerevisiae Hansen CBS 5926. Según la evolución de cuadro diarreico se juzgó la puntuación previamente establecida en el protocolo y en relación con los síntomas o signos (fiebre, náuseas, vómitos y cólico abdominal); el número de evacuaciones, su consistencia, color de las heces y efectos colaterales. la dosis dependió de la edad y peso, sin riesgos por ser atóxica. Todos los pacientes correspondieron a un nivel socio económico bajo en donde el índice de deserción fue de 33% y existió duda sobre la continuidad del tratamiento. Los resultados fueron en 50% muy eficaz, poco eficaz en 15% e ineficaz en 25%. Es necesario señalar que 30% de los niños tratados habian recibido previamente tratamiento con anticolinérgicos, astringentes y antibióticos