Preparation and Properties of Wheat and Corn Starch Maltodextrins with a Low Dextrose Equivalent

Wheat and corn maltodextrins (W‐MD 8 and C‐MD 8) with dextrose equivalent (DE) 2–3 were prepared by heterogeneous bacterial α‐amylase digestion of a 15% starch paste at 95°C for 8 min followed by cooling and spray‐drying. Gels of the two maltodextrins appeared opaque with a glossy surface and melted reversibly at ≈65°C. Scanning electron micrographs showed that the products were divided finely and had few large remnants of starch granules. The fine granulation of W‐MD 8 and C‐MD 8 caused some clumping in cold water; homogeneous solutions were achieved with vigorous stirring at 90°C. Size‐exclusion chromatograms showed that the two products contained similar broad, molecular‐weight distributions of saccharides. A commercial potato maltodextrin marketed as a fat‐replacer contained fewer short‐length molecules when compared to W‐MD 8 and C‐MD 8, whereas a commercial corn maltodextrin fatreplacer contained more. High‐performance anion‐exchange chromatography with pulsed‐amperometric detection showed that all four maltodextrins contained only linear maltosaccharides between DP 2 and 25, with elevated levels of maltotriose and maltohexaose. The new wheat and corn maltodextrins contained 0.6–1.0% lipids and became rancid when stored at >30°C. The rancidity development in W‐MD 8 was eliminated either by alkali treatment of starting starch or by charcoal treatment of the warm hydrolyzate.