ARS | Publication request: PREPARATION OF STARCH SUCCINATES BY REACTIVE EXTRUSION

Submitted to: Starch
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 18, 1996
Publication Date: N/A

Interpretive Summary: Chemically modified starches such as starch succinate have wide use as thickeners in foods, coatings for paper, textile manufacturing and tablet disintegrants. Currently, most modified starches are prepared via batch processes which require long times and give granular starches which have to be heated in water in order to dissolve. This paper describes the use of a screw extruder to prepare starch succinates very rapidly and in a form which can be directly dissolved in cold water. Although the process needs to be improved to be commercially feasible, some of the starch succinates appear to be promising as thickening agents. These results should be of benefit to scientists and companies working to develop new and expanded uses for cornstarch.

Technical Abstract: The succinylation of cornstarch by extrusion processing has been studied. Several different factors affecting the succinylation of starch were investigated including water content, succinic anhydride quantity, catalyst type and quantity, and reaction temperature. The degree of substitution (DS) increases with decreasing water content and increasing succinic anhydride quantity. Higher temperature favors higher DS using sodium bicarbonate as catalyst while the opposite is true using magnesium hydroxide as catalyst. Of the three catalysts used, sodium bicarbonate is best. Aqueous solubility and viscosity of the starch succinates tend to increase with increasing DS. Based on the results of aqueous solution viscosity, some samples appear to be promising as commercial thickening agents.