A friend asked me about high maltose corn syrup the other day and whether it was as bad as HFCS, and I had absolutely no idea what the stuff was. So, I thought I'd educate myself and then do a post on high maltose corn syrup in case any of you dear readers run across it in an ingredient list.
There are lots of different sugars out there, and maltose is but one of them. For example, lactose is a common sugar found in dairy products that is a disaccharide (or two sugars joined together) of glucose and galactose. (People have lactose intolerance when their body is missing or doesn't have enough of the enzyme lactase to process the sugar.) Fructose is a sugar that is found in fruit and honey. Maltose is another commonly found sugar. It's a disaccharide that is composed of two glucose molecules. It also goes by the name "malt sugar" and is the primary sugar in beer. Maltose isn't as sweet as fructose. Fortunately, our bodies have an enzyme (maltase) that easily breaks down maltose into two glucose molecules, and glucose is easy for our bodies to process.
So, high maltose corn syrup (also known as maltodextrin) is a corn syrup that is rich in maltose, just as HFCS contains fructose as its major sugar. High maltose corn syrup is a specially prepared acid-enzyme converted corn syrup. High maltose corn syrup is used to replace sucrose (table sugar) because it can improve flavor, body, and texture while imparting resistance to color formation, moisture absorption, and crystallization in products such as hard candy (http://www.riddhisiddhi.co.in/prod_lg.htm).
So, there you go. The short answer is that high maltose corn syrup is still a processed food, but it is not nearly as heinous as HFCS. It's basically maltose (a couple of nice glucose molecules stuck together) floating around in a glucose syrup. I haven't seen high maltose corn syrup yet, but I have seen maltodextrin.