High fructose syrups (HFS) are manufactured by controlled enzymatic isomerisation of dextrose to a concentration of about 42% fructose. Consequently, fructose syrup is almost completely composed of mono-saccharides, i.e. dextrose and fructose.

To obtain a higher fructose concentration it is necessary to separate the dextrose and the fructose fractions. The dextrose fraction is then re-entered prior to the isomerisation. Fractionation of the resulting dextrose-fructose mixture by liquid chromatography can increase the fructose fraction to 90% or higher. By blending the fructose fraction with 42% fructose syrup it is possible to make products with desired fructose/dextrose ratios. Fructose 55 is a common blend used in the soft drink industry.

Fructose 55 has the same sweetening properties as sucrose (sugar); however, this replacement will improve the texture of ice cream and make it perfectly smooth. The sweetening power of fructose syrup benefits from the phenomenon of synergy: the sweetening power of a mixture of sucrose and fructose syrup is higher than the pure arithmetic addition of the components taken separately.