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Pectin
Pectin ( ': "congealed" and "curdled") is a heteropolysaccharide, a structural polymer contained in the primary lamella, in the middle lamella, and in the cell walls of terrestrial plants. The principal chemical component of pectin is galacturonic acid (a sugar acid derived from galactose) which was isolated and described by Henri Braconnot in 1825. Commercially produced pectin is a white-to-light-brown powder, produced from citrus fruits for use as an edible gelling agent, especially in jams and jellies, dessert fillings, medications, and sweets; as a food stabiliser in fruit juices and milk drinks, and as a source of dietary fiber. Biology Pectin is composed of complex polysaccharides that are present in the primary cell walls of a plant, and are abundant in the green parts of terrestrial plants. Pectin is the principal component of the middle lamella, where it binds cells. Pectin is deposited by exocytosis into the cell wall via vesicles produced in the Golgi appara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pectinase
Pectinases are a group of enzymes that breaks down pectin, a polysaccharide found in plant cell walls, through hydrolysis, transelimination and deesterification reactions. Commonly referred to as pectic enzymes, they include pectolyase, pectozyme, and polygalacturonase, one of the most studied and widely used commercial pectinases. It is useful because pectin is the jelly-like matrix which helps cement plant cells together and in which other cell wall components, such as cellulose fibrils, are embedded. Therefore, pectinase enzymes are commonly used in processes involving the degradation of plant materials, such as speeding up the extraction of fruit juice from fruit, including apples and sapota. Pectinases have also been used in wine production since the 1960s. The function of pectinase in brewing is twofold, first it helps break down the plant (typically fruit) material and so helps the extraction of flavors from the mash. Secondly the presence of pectin in finished wine causes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pectinesterase
Pectinesterase (EC 3.1.1.11; systematic name pectin pectylhydrolase) is a ubiquitous cell-wall-associated enzyme that presents several isoforms that facilitate plant cell wall modification and subsequent breakdown. It catalyzes the following reaction: :pectin + ''n'' H2O = ''n'' methanol + pectate It is found in all higher plants as well as in some bacteria and fungi. Pectinesterase functions primarily by altering the localised pH of the cell wall resulting in alterations in cell wall integrity. Pectinesterase catalyses the de-esterification of pectin into pectate and methanol. Pectin is one of the main components of the plant cell wall. In plants, pectinesterase plays an important role in cell wall metabolism during fruit ripening. In plant bacterial pathogens such as ''Erwinia carotovora'' and in fungal pathogens such as ''Aspergillus niger'', pectinesterase is involved in maceration and soft-rotting of plant tissue. Plant pectinesterases are regulated by pectinesterase in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heteropolysaccharide
Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long-chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with water (hydrolysis) using amylase enzymes as catalyst, which produces constituent sugars (monosaccharides or oligosaccharides). They range in structure from linear to highly branched. Examples include storage polysaccharides such as starch, glycogen and galactogen and structural polysaccharides such as hemicellulose and chitin. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure, these macromolecules can have distinct properties from their monosaccharide building blocks. They may be amorphous or even insoluble in water. When all the monosaccharides in a polysaccharide are the same type, the polysaccharide is called a homopolysaccharide or homoglycan, but when more t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galacturonic Acid
-Galacturonic acid is a sugar acid, an oxidized form of -galactose. It is the main component of pectin, in which it exists as the polymer polygalacturonic acid. In its open form, it has an aldehyde group at C1 and a carboxylic acid group at C6. Other oxidized forms of -galactose are -galactonic acid (carboxylic group at C1) and ''meso''-galactaric acid ( mucic acid) (carboxylic groups at C1 and C6). It is also a uronic acid or hexuronic acid. Naturally occurring uronic acids are -glucuronic acid, -galacturonic acid, - iduronic acid and -mannuronic acid Mannuronic acid is a uronic acid monosaccharide that can be derived from mannose. Along with -guluronic acid, -mannuronic acid is a component of alginic acid, a polysaccharide found predominantly in brown algae Brown algae (: alga) are a lar .... References {{DEFAULTSORT:Galacturonic acid, D- Uronic acids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
D-Galacturonic Acid
-Galacturonic acid is a sugar acid, an oxidized form of -galactose. It is the main component of pectin, in which it exists as the polymer polygalacturonic acid. In its open form, it has an aldehyde group at C1 and a carboxylic acid group at C6. Other oxidized forms of -galactose are -galactonic acid (carboxylic group at C1) and ''meso''-galactaric acid (mucic acid) (carboxylic groups at C1 and C6). It is also a uronic acid or hexuronic acid. Naturally occurring uronic acids are -glucuronic acid, -galacturonic acid, -iduronic acid and -mannuronic acid Mannuronic acid is a uronic acid monosaccharide that can be derived from mannose. Along with -guluronic acid, -mannuronic acid is a component of alginic acid, a polysaccharide found predominantly in brown algae Brown algae (: alga) are a lar .... References {{DEFAULTSORT:Galacturonic acid, D- Uronic acids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galacturonic Acid
-Galacturonic acid is a sugar acid, an oxidized form of -galactose. It is the main component of pectin, in which it exists as the polymer polygalacturonic acid. In its open form, it has an aldehyde group at C1 and a carboxylic acid group at C6. Other oxidized forms of -galactose are -galactonic acid (carboxylic group at C1) and ''meso''-galactaric acid ( mucic acid) (carboxylic groups at C1 and C6). It is also a uronic acid or hexuronic acid. Naturally occurring uronic acids are -glucuronic acid, -galacturonic acid, - iduronic acid and -mannuronic acid Mannuronic acid is a uronic acid monosaccharide that can be derived from mannose. Along with -guluronic acid, -mannuronic acid is a component of alginic acid, a polysaccharide found predominantly in brown algae Brown algae (: alga) are a lar .... References {{DEFAULTSORT:Galacturonic acid, D- Uronic acids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dietary Fiber
Dietary fiber (fibre in English in the Commonwealth of Nations, Commonwealth English) or roughage is the portion of plant-derived food that cannot be completely broken down by human digestive enzymes. Dietary fibers are diverse in chemical composition and can be grouped generally by their solubility, viscosity and Fermentation#Biological role, fermentability which affect how fibers are processed in the body. Dietary fiber has two main subtypes: soluble fiber and insoluble fiber which are components of plant-based foods such as legumes, whole grains, cereals, vegetables, fruits, and nut (fruit), nuts or seeds. A diet high in regular fiber consumption is generally associated with supporting health and lowering the risk of several diseases. Dietary fiber consists of non-starch polysaccharides and other plant components such as cellulose, resistant starch, resistant dextrins, inulins, lignins, chitins, pectins, beta-glucans, and oligosaccharides. Food sources of dietary fiber have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petiole (botany)
In botany, the petiole () is the stalk that attaches the leaf blade to the Plant stem, stem. It is able to twist the leaf to face the sun, producing a characteristic foliage arrangement (spacing of blades), and also optimizing its exposure to sunlight. Outgrowths appearing on each side of the petiole in some species are called stipules. The terms wikt:petiolate, petiolate and wikt:apetiolate, apetiolate are applied respectively to leaves with and without petioles. Description The petiole is a stalk that attaches a leaf to the plant stem. In petiolate leaves the leaf stalk may be long (as in the leaves of celery and rhubarb), or short (for example basil). When completely absent, the blade attaches directly to the stem and is said to be Sessility (botany), sessile or apetiolate. Subpetiolate leaves have an extremely short petiole, and may appear sessile. The broomrape family Orobanchaceae is an example of a family in which the leaves are always sessile. In some other plant group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylose
Xylose ( , , "wood") is a sugar first isolated from wood, and named for it. Xylose is classified as a monosaccharide of the aldopentose type, which means that it contains five carbon atoms and includes an aldehyde functional group. It is derived from hemicellulose, one of the main constituents of biomass. Like most sugars, it can adopt several structures depending on conditions. With its free aldehyde group, it is a reducing sugar. Structure The acyclic form of xylose has chemical formula . The cyclic hemiacetal isomers are more prevalent in solution and are of two types: the pyranoses, which feature six-membered rings, and the furanoses, which feature five-membered rings (with a pendant group). Each of these rings is subject to further isomerism, depending on the relative orientation of the anomeric hydroxy group. The dextrorotary form, -xylose, is the one that usually occurs endogenously in living things. A levorotary form, -xylose, can be synthesized. Occurren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prebiotic (nutrition)
Prebiotics are compounds in food that foster growth or activity of beneficial microorganisms such as bacteria and fungi. The most common environment concerning their effects on human health is the gastrointestinal tract, where prebiotics can alter the composition of organisms in the gut microbiome. Dietary prebiotics are typically nondigestible fiber compounds that pass undigested through the upper part of the gastrointestinal tract and help growth or activity of advantageous bacteria in the colon by acting as substrates for them. They were first identified and named by Marcel Roberfroid in 1995. Depending on the jurisdiction, they may have regulatory scrutiny as food additives for the health claims made for marketing purposes. Common prebiotics used in food manufacturing include beta-glucan from oats, resistant starch from grains and beans, and inulin from chicory root. Definition The definition of prebiotics and the food ingredients that can fall under this classificat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Short-chain Fatty Acid
Short-chain fatty acids (SCFAs) are fatty acids of two to six carbon atoms. The SCFAs' lower limit is interpreted differently, either with one, two, three or four carbon atoms. Derived from intestine, intestinal microbe, microbial fermentation of indigestible foods, SCFAs in human gut are acetic, propionic and butyric acid. They are the main energy source of colonocytes, making them crucial to gastrointestinal health. SCFAs all possess varying degrees of water solubility, which distinguishes them from longer chain fatty acids that are immiscible. List of SCFAs Functions SCFAs are produced when dietary fiber is fermented in the Colon (anatomy), colon. Macronutrient composition (carbohydrate, protein or fat) of diets affects circulating SCFAs. Acetate, propionate and butyrate are the three most common SCFAs. Butyric acid, Butyrate is particularly important for large intestine, colon health because it is the primary energy source for Gastrointestinal tract#Mucosa, colonocytes (the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
