On the use of differential solubility in aqueous ethanol solutions to narrow the DP range of food-grade starch hydrolysis products

• Approaches to the fractionation of starch hydrolysis products (SHP) are described.
• Fractionations were based on differential solubility in 50–95% aqueous ethanol.
• The molecular dispersity of representative SHP fractions is presented.
• Chemical and spectroscopic analyses of representative SHP fractions are presented.
• A simple method for obtaining refined food-grade SHP preparations is outlined.

Considerable research is focused on understanding the functionality of starch hydrolysis products (SHP) consisting of glucose, maltose, maltooligosaccharides (MOS), and maltopolysaccharides (MPS). A confounding factor in this research is the high molecular dispersity of commercially available SHP. The study presented herein characterizes a flexible fractionation approach for lowering the dispersity of such products. This was accomplished by fractionating a corn syrup solids (CSS) preparation based on the differential solubility of its component saccharides in aqueous-ethanol solutions. Products obtained from selected fractionations were characterized with respect to degree of polymerization (DP; liquid chromatography), dextrose equivalency (reducing sugar assays), and prevalence of branching (NMR). Glucose and maltose were preferentially removed from CSS using high (⩾90%) ethanol extractants. Preparations with relatively narrow ranges of MOS, lower DP MPS, and higher DP MPS were obtained through repetitive 70%-ethanol extractions. Linear, as opposed to branched, MOS and MPS were preferentially extracted under all conditions tested.