Abstract: Novel mixed partial esters of certain carbohydrates and sugars are prepared by reacting the carbohydrate starting material with an aliphatic acylation agent having up to two carbon atoms in the chain until the resulting product has an acylation number of up to one acyl group per monose unit, and then reacting the mixture with a higher fatty acid reactant having at least six carbon atoms in the chain in the presence of an acid catalyst. The acylation agent and fatty acid reactant may be in the form of the free acid or the anhydride, examples of both being disclosed, and the carbohydrate starting material may be present in aqueous solution or suspension. The novel esters, which may contain 7 or more % of combined higher fatty acid have desirable interfacial properties and are biodegradable.