An acidic sweetener is provided that is a single additive effective to provide both sweetness and acidity to a food item or other comestible. Preferably, the acidic sweetener has a low glycemic index value to generally improve the nutritional profile of the comestible to which it is added. A method to produce a food item using the acidic sweetener is also provided. The method converts a syrup sweetener to the acidic sweetener additive. In a preferred form, the method uses an enzyme mixture of glucose oxidase and catalase to convert a portion of the glucose in the syrup sweetener into gluconic acid.