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The Look and Feel of Food
Published in Alan R. Hirsch, Nutrition and Sensation, 2023
Sanford S. Sherman, Mary Beth Gallant-Shean, Alan R. Hirsch
Astringency is the perception of drying or puckering, as is prototypically seen in response to tannic acid in dry wine or the mouth somesthetic sensation in response to the introduction of strong lemon juice (Bates-Smith 1954). Such a sensation may reflect a combination of touch receptors, through meissner’s corpuscles and mechanoreception for deformation with activation of pacinian corpuscles. Such activation may come directly from the consumed thermal, or indirectly as a result of salivary production inhibition inducing changes to physiological set points in the oral epithelium, inducing greater sensitivity to chemical external stimuli (Joslyn and Goldstein 1964). Supporting such a theory, tannic acid-induced astringency (or dryness) was reduced by the addition of the sialogogue, sucrose (Lyman and Green 1990). The astringency of a food is partially dependent on its ability to precipitate salivary proteins (Noble 1995). Such precipitants reinforce astringency (Green 1993). Cross-linking of proteins may enhance tension thus stimulating mechanoreceptors.
Characterization of Phyto-Constituents
Published in Rohit Dutt, Anil K. Sharma, Raj K. Keservani, Vandana Garg, Promising Drug Molecules of Natural Origin, 2020
Himangini, Faizana Fayaz, Anjali
Tannins are complicated, nonnitrogenous derivatives of polyhydroxy benzoic acid having a special quality to tan, i.e. to change things into the leather. The word tannin basically refers to the use of wooden tannins from oak in tanning animal hides into leather; hence the words “tan” and “tanning” for the remedy of leather. They have acidic nature which is present because of the phenolic or carboxylic group present in its moiety. They create complex structure with gelatin, carbohydrates, proteins, and alkaloids. They are mainly obtained in aerial parts of plants like fruits, barks of immature plants, leaves, and disappear on ripening. Tannins have molecular weights ranging from 500 to over 3,000 and up to 20,000. The astringent nature of tannins reasons dry and puckery feeling inside the mouth when fed on unripe (Ashok et al., 2012).
Potential of Phytochemicals in the Treatment of Hemorrhoids
Published in Megh R. Goyal, Durgesh Nandini Chauhan, Assessment of Medicinal Plants for Human Health, 2020
Besides general treatment, plant-based intestinal regulators and plant-based phlebotonics are usually preferred by patients. The astringent effect of plants is parallel to the anti-hemorrhoidal influence.8 Tannin is a secondary metabolite, which has astringent activity. It is one of the major chemicals of Hamamelis virginiana L., Juglans regia L., Cassia sp., and Quercus sp. There are many herbal remedies in the market, containing mostly Hamamelis virginiana L.47 Besides, anti-inflammatory activity is closely related to capillary permeability related illness. Flavonoid derivatives are also effective for venous diseases such as varicose vein and hemorrhoid.61 Additionally, saponin derivatives isolated from Aesculus hippocastanum L. and Ruscus aculeatus L. are active ingredients in related herbal medicines.
Lobularia maritima leave extract, a nutraceutical agent with antioxidant activity, protects against CCl4-induced liver injury in mice
Published in Drug and Chemical Toxicology, 2022
Anis Ben Hsouna, Sabah Dhibi, Wissal Dhifi, Rania Ben Saad, Faical Brini, Najla Hfaidh, Jackson Roberto Guedes da Silva Almeida, Wissem Mnif
Among medicinal plants, Lobularia maritima (Alyssum maritimum, Brassicaceae), commonly known as sweet alyssum or sweet alison, is an annual ornamental halophyte endemic to Tunisia. It can tolerate salinity up to 400 mM NaCl (Ben Hsouna et al.2019). The leaves are quite small (simple, arranged alternately along the lower part of the stem with a fusiform shape, smooth outline. Their shiny grayish green color is due to the presence of many flattened fine white bristles (Asakawa and Asakawa 2001). The plant is commonly used in Spain as an antiscorbutic and diuretic (Chopra et al.1986). It is also highly esteemed as an astringent (Chopra et al.1986). The young leaves, stems, and flowers are sometimes used as flavoring in salads and other dishes where pungency is required (Facciola 1990).
Health effects, sources, utilization and safety of tannins: a critical review
Published in Toxin Reviews, 2021
Kartik Sharma, Vikas Kumar, Jaspreet Kaur, Beenu Tanwar, Ankit Goyal, Rakesh Sharma, Yogesh Gat, Ashwani Kumar
Although tannin is widely used due to its beneficial properties, it also possesses certain adverse effects. Tannin’s property of imparting astringency which is used as an advantage in beverage industry is one the major disadvantage for other food industries as it leads to reduced palatability of food products (Price and Butler 1980). Tannin exhibits antinutritional properties by forming complexes with minor elements such as phosphorus, calcium, magnesium, etc., as well as with major elements such as carbohydrates, proteins and rendering them unavailable for the utilization by the body (Waghorn et al.1994, Hagerman et al.1998). It also forms complexes with enzymes that are involved in digestion of carbohydrates, proteins, pectins because of which they cannot act upon and this in turn is responsible for lowering the nutritional quality of the food. Consumption of too much of tannins in beverages such as tea, coffee without milk can often lead to diseases such as anemia, osteoporosis that can go worst upto cancer (Ricardo‐da‐Silva et al. 1991). A complete detail of adverse effect of tannin is given in Table 3b. Several adverse effects of tannins on plant growth and development reported by different researchers have been discussed in Table 4.
Left out in the cold: Serving wines chilled
Published in Temperature, 2019
Although also perceived in the mouth, astringency and irritation are not tastes. In wine, astringency is the rough or drying sensation that occurs when tannins interact with salivary proteins to reduce lubrication within the oral cavity, whereas irritation is the burning sensation elicited by high concentrations of ethanol. Both astringency and irritation are temperature-dependent. Chilling reduces perceived astringency albeit the effects are fairly small [4]. Suppression of astringency may be due to (a) decreased solution viscosity of the refrigerated solution, (b) a higher salivary flow rate in response to cold solutions, or (c) reduced tannin-protein interactions resulting from colder temperatures. Solution viscosity, salivary flow rate, and the degree of protein-compound interaction have all been shown to affect perceived astringency. When some wines (particularly red varietals) are consumed above optimal serving temperatures, connoisseurs will often characterize them as “hot”. This “hot” sensation is typically evoked in wines with relatively high alcohol content. Ethanol elicits this sensation by activating a temperature-sensitive receptor (TRPV1) normally responsive to hot temperatures [5]. Cooling reduces the likelihood of TRPV1 being activated. Not surprisingly, chilling a wine therefore, will decrease the activation of TRPV1 by ethanol and consequently reduce the “hot”, irritant sensation from the wine.