Analysis and modification of pectin

Broek, Ben van den; Stoutjesdijk, Jan; Mulder, Wim; Essers, Maurice; Haveren, Jacco van


Pectin is one of the major plant cell wall polysaccharides. It is present in the primary cell wall and middle lamella of the plant. The function of pectin is to strengthen the cell wall and “keeping” the cells together. The main commercial sources of pectin are from the peels of citrus fruits and apple pomace. Extraction is performed at acid conditions at elevated temperatures and often an alcohol precipitation is used to concentrate the pectin. The polysaccharide consist predominantly of a so-called “smooth region” containing galacturonic acid moieties that can be methyl esterified. In addition the homogalacturonan chains contain alternating “hairy regions” of rhamnogalacturonan that consists of rhamnose and galacturonic acid repeats which contain side chains of arabinan and/or galactan moieties. The latter is depending on the source. The main application of pectin is in the food industry where it is used as gelling agent, thickener and as stabilizer in beverages and ice creams.In Europa sugar beets (Beta vulgaris L.) are used for the production of sucrose. A side product is sugar beet pulp that is obtained after sugar extraction. At yearly basis about 5-6 million tons dry matter sugar beet pulp is produced which is mainly used as feed. In order to increase the economic value a biorefinery is designed by Royal Cosun (The Netherlands) for the production of different value added components from sugar beet pulp. One of these components is sugar beet pectin. In contrast to pectin from citrus fruits and apple pomace, sugar beet pectin has a shorter length of the “smooth regions”, a higher amount of “hairy regions” and a higher degree of acetylation. The combination of all these parameters result in poor gelling properties. In the project TKI-AF 17024 “Non-food applications of polysaccharides from sugar beet pulp” the properties of sugar beet pectin are determined. In addition the chemical and/or enzymatic modification of sugar beet pectin is performed to improve its properties.Wageningen Food & Biobased Research determines the chemical structures and investigates the properties of the (modified) sugar beet pectins like foaming, viscosity, hydrophobicity, emulsification and surface tension. Based on the structure-function relation is can be predicted for what kind of application the sugar beet pectins and derivatives hereof can be used. Other industrial partners involved in this project are, next to Royal Cosun, Dalli de Klok B.V. part of the Dalli Group, Smit & Zoon and Rodenburg Biopolymers. All companies are interested to increase their biobased content by using sugar beet pectin in their products like dishwasher tablets, chemicals for leather treatment and bioplastics, respectively. In addition to replacing components made from fossil resources the sugar beet pectin is analyzed if it is also able to improve the properties of the commercial end products.