|Chau, Hoa - Rose|
Submitted to: Carbohydrate Polymers
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/29/2009
Publication Date: 7/5/2009
Citation: Simkovic, I., Nunez, A., Strahan, G.D., Yadav, M.P., Chau, H.K., Meddichi, R., Hicks, K.B. 2009. Fractionation of sugar beet pulp by introducing ion-exchange groups. Carbohydrate Polymers. 78:806-812. Interpretive Summary: The enormous volume of fruit and vegetable processing residues, such as sugar beet pulp, represents an underutilized domestic resource that contains renewable feedstocks for the production of value-added coproducts. These residues have been used as cattle feed ingredients, but as such their typical value is low (under $0.05/pound) and there is often more supply than demand. However, these residues are rich in valuable carbohydrates that can be used for food ingredients and biobased products. It has been difficult to extract these carbohydrates from sugar beet pulp without degrading them and causing loss of functionality. For the first time, we were able to extract valuable carbohydrates from sugar beet pulp and simultaneously introduce new and useful chemical functionality. These new biobased products may be used for binding heavy metals or as valuable coating agents for paper products. Further development of these carbohydrate materials into commercial products will add value to the U.S. sugar beet processing industry, and will benefit growers, processors as well as consumers.
Technical Abstract: Sugar beet pulp (SBP) was chemically modified with the goal to utilize this method for the preparation of water-soluble polysaccharides. Yields of the trimethylammoniumhydroxypropylated (TMAHP) polysaccharide fractions prepared under vacuum in absence of NaOH or KOH, as well as their molar masses, were higher than those obtained when the samples were only extracted with hydroxide at ambient pressure. The hydroxypropylsulfonated (HPS) fractions extracted at ambient pressure with NaOH had higher yields and molar mass than the TMAHP fractions extracted under vacuum with KOH. Introduction of both ion-exchange groups in one step under vacuum with NaOH gave better yields than with KOH, but smaller than for the solely sulfonated sample. The molar masses of chemically modified fractions were smaller than those extracted only with alkali or water. According to the monosaccharide composition all the fractions are mixtures of arabinogalactans and rhamnogalacturonans.