In the U.S., starch usually means corn starch, either common or waxy, often chemically modified for extra functionality. In Europe, starches are more often wheat, potato or tapioca, with a different set of chemical modifications, or sometimes no chemical modifications at all. One reason is shelf-life priorities are different in different countries.
Lately, U.S. priorities are changing, triggered by changing dietary preferences of consumers. Today, starches may need to be appropriate for organic labeling or other carbohydrate combinations, such as "resistant" starches, or part of grain flours or other carbohydrate components of grains or tubers.
Starches are used to improve the functionality of mixed food systems, and one of the components that may cause problems is indigenous starches. These starches often are not well characterized, so overcoming "set-back" or syneresis caused by native starches may require the addition of modified starches or other ingredients.
When talking about the role of starch in food systems, there are two parts to the equation: starch added to improve function and starch that is naturally present and could cause interactions with added starch to the detriment of the food system.
The difference between a starch from corn or one from potato can depend on the structure of the starch, controlled by the kinds of polymers found in the grain or tuber and the way the polymers are packed into the starch granule. Polymers are characterized as amylose (linear starch) or amylopectin (branched starch). But there are many variations between one amylopectin starch (often called waxy starches) and another, as well as differences between the length and texture of amylose starches. These are governed by a set of enzymes that trigger branches and size.
A waxy rice starch produces foods that are different in texture and other attributes than a waxy potato or a waxy barley starch. If a consumer is accustomed to eating foods made with rice starch, the texture will be different when the food is made with another starch.
Some of the alternatives to corn starch have been around for decades, but because of shipment and handling, have been more expensive than corn or waxy corn starches. Potato starch generally is more expensive than corn but has different attributes, such as forming a gel and "set back" to form different textures unless it is chemically modified. The cost of chemical modification is variable, but highly modified starches can be very expensive. Recently, new starches in addition to potato, tapioca and rice starches are appearing in the marketplace.
Starch from legumes
When concerns about modified starches hit the baby food industry, at least one firm advertised they would "add more food" to baby foods, replacing the starches. The assumption by the consumer was starch added nothing to nutrition of baby foods.
Of course, in many cases the "more food," especially vegetables, contain large amounts of starch. So, in adding more food, the primary action was to add pea or bean starch (or carrot or apple). Today, starch from peas and beans are being used to control the glycemic index of foods, as these starches resemble resistant starch and pass through the gut without being absorbed by the body.
"Use of the white bean starch reduces the glycemic index of white bread significantly," according to Jay Udani, medical director for Medicus Research LLC (www.medicusresearch.com), Northridge, Calif.
One such product is Starchlite, the product of Pharmachem Laboratories Inc., (www.pharmachemlabs.com), Kearny, N.J., a standardized, all-natural extract of the common white bean (Phaseolus vulgaris). It has been clinically shown to delay the digestion and absorption of carbohydrates, reducing caloric impact, glucose impact and the glycemic index of starchy foods.
Starchlite may be used as an ingredient in a variety of foods and beverages, including baked goods, cereals, frozen foods, packaged meals, pasta, pizza crust, soups and confectionary. Sensory evaluations show Starchlite has no negative effect on the taste or texture of foods.
Affirmed GRAS in July 2006, Pharmachem received a letter last November from the FDA authorizing the following structure/function claim for Starchlite: "May reduce the enzymatic digestion of dietary starches" or "May assist in weight control when used in conjunction with a sensible diet and exercise program."
Nutri-Pea Ltd. (www.parrheim.com), Portage la Prairie, Manitoba, produces Accu-Gel, made from the kernels of golden Canadian peas. Field peas, as they are called in Canada, are a little higher in the linear fraction starch than common corn, so pea starch is about 35 percent amylose and 65 percent amylopectin.