Froctose is generally refined from corn starch. This sweeteners begin with enzymes which isomerize dextrose to produce a 42% fructose syrup. By passing 42-FCS through a column which retains fructose, refiners draw off 90% FCS and blend it with 42-FCS to make a third syrup, 55-FCS. All the syrups share advantages - stability, high osmotic preasure, or crystallization control, for example - but each offers special qualities to food manufactures and consumers. 42-FCS is popular in canned fruits, condiments, and other processed foods which need mild sweetness that won't mask natural flavors. Sweeter 55-FCS has earned a commanding role in soft drinks, ice cream, and frozen desserts. Supersweet 90-FCS is valued in natural and "light" foods, where very little is needed to provide sweetness. Crystalline fructose's capacity to produce greater sweetness in combination with sugar makes it useful in presweetened cereals, instant beverages, and other dry mix products.
Fructose is generally refined from corn starch. It is claimed to be anywhere from 15 to 80% sweeter than sucrose, and tastes particularly sweet when cold or in solution. It is believed to be absorbed into the gastro-intestinal tract more slowly than glucose, and does not require insulin for entry into the liver. These features make it appealing to diabetics, but the advantages are somewhat offset by its higher tendency to be converted to fat rather than glycogen, thereby elevating blood triglyceride levels.