Pear pectin

Arabinogalactans (AGs) are widely spread throughout the plant kingdom. Many edible and inedible plants are rich sources of these polysaccharides. AGs occur in two structurally different forms described as type I and type II, associated with the pectin cell-wall component by physical bonds and some of them are covalently linked to the complex pectin molecule as neutral side chains. Commercial pectins always contain AG 10-15%). AG of type I has a linear (1 4)-y0-o-Galp backbone, bearing 20-40% of of-L-Ara/ residues (1 5)-linked in short chains, in general at position 3. It is commonly found in pectins from citrus, apple and potato [6]. Recently, this AG type has been isolated from the skin of Opuntia ficus indica pear fruits [372]. 

These studies demonstrate that the processing of cactus pears into coloring preparations is feasible. It is now up to companies to exploit the enormous potential of these fruits. The by-products from Opuntia processing such as seeds and peels could be further processed into vegetable oil and pectin, respectively. 

Fernandez LM, Lin ECK, Trejo A and McNamara DJ. 1992. Prickly pear (Opuntia sp.) pectin reverses low density lipoprotein receptor suppression induced by a hypercholesterolemic diet in Guinea Pigs. J Nutt 122 2330-2340. 

Peach (Primus persica) 365 Pear (Pirus communis) 365 Pectin 361 PEDOT e26... 

Fernandez, M.L., Lin, E.C., Trejo, A., and McNamara, DJ. 1994. Prickly pear (Opuntia sp.) pectin alters hepatic cholesterol metabolism without affecting cholesterol absorption in guinea pigs fed a hypercholesterolemic diet. J. Nutr. 124, 817-824. 

Apple, pear, orange and grape juices are all clarified by ultrafiltration. Ultrafiltration of apple juice is a particularly successful application. Approximately 200 plants have been installed, and almost all US apple juice is clarified by this method. In the traditional process, crude filtration was performed directly after crushing the fruit. Pectinase was added to hydrolyze pectin, which reduced the viscosity of the juice before it was passed through a series of decantation and... 

The analysis of acidic cell wall polymers (notably pectins) can also be complicated by their tendency to precipitate in acidic media. Jermyn and Isherwood (1956) found that aqueous solutions of pectic polymers from pear cell walls precipitated on the addition of nitric acid. If, however, the sample was warmed prior to the slow addition of acid, precipitation could be avoided. Ford (1982) has shown that quantitative analysis of water-soluble pectic polysaccharides can be improved by depolymerization with a poly-( 1,4-a-D-galacturonide)-glycanohydrolase (EC 3.2.1.15). This treatment can also be used prior to acid hydrolysis to prevent polymer aggregation. Although the recovery of neutral monosaccharides is increased, the stability of the glycosiduronic linkage still prevents its complete hydrolysis. 

The cellular tissue of many fruits contains cellulose associated with other substances of the nature of carbohydrates. Apples, pears, and other fruits contain a substance called pecto-cellulose, which is probably a chemical compound of cellulose and pectin, as it gives cellulose and pectic acid on hydrolysis with an alkali. Pectin, which is a complex carbohydrate present in certain fruits, is converted into pectic acid when heated with a solution of an alkali. The formation of jellies from fruits is brought about as the result of the hydrolysis of the pectin which they contain. The hydrolysis converts pectin into pectic acid, which forms calcium pectate with the calcium salts always... 

Pectin was discovered in the nineteenth century and has been used at home and in industry for making jams and jellies ever since. The first recipes reported were posted by "London Housewife s Family Companion in 1750, which described its preparation from apple, quince and currant fruit, currently used as sources of extraction [30]. In 1825, Henri Braconot [10] was the first to report pectin extraction, conducting trials first with dahlia tuber, Jerusalem artichoke, celery, and then with apple, pear and plum. The acid character of this compound was discovered and its ability to gel. This was the first scientific report about pectin that we have as evidence. 

Lira-Ortiz, A. L., Resendiz-Vega, E, Rios-Leal, E., Contreras-Esquivel, J. C., Chavarria-Hernandez, N., Vargas-Torres, A, and Rodriguez-Hernandez, A. I. (2014). Pectins from waste of prickly pear fruits (Opuntia albicarpa Scheinvar "Reyna") Chemical and rheological properties. Food HydrocoIIoids, 37(0), 93-99. 

Forni, E., Penc,i M. Polesello, A. (1994). A preliminary characterization of some pectins from quince fruit Cydonia oblonga Mill) and pickly pear Opuntia ficus indica) peel. Carbohydrate polymers, 23, 4, 231-295. 

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