Glucose syrup is principally manufactured from corn. At one time only one type of glucose syrup was manufactured - 42 Dextrose Equivalent, but today automation of the production process means that different compositions of glucose syrup can be made. Corn syrup or glucose syrup can be used as a sweetener in chocolate but it has a high water content which affects the rheological or flow properties of the chocolate, so it is not often used. Glucose syrup is used in fondants, toffees etc.