We all want foods and beverages with great mouthfeel and taste, but don't want to fill up with fat, calories and sugar. Product developers recognize that low-fat, high-fiber and low carbs are critical factors today for baked goods and snack formulations.
Starches can help. Starch can be extracted from more than 50 types of plants and supports sauces, puddings, pie fillings and soups. Starch may also be added to frozen products to prevent them from dripping when defrosted.
But not all starches are created equal. These polysaccharides vary widely in quality, granular shape, size, amylose content and viscosity and in how they thicken and flavor the finished products.
Most are made from grains, roots or tubers. The most common forms of grain starches are wheat flour and cornstarch. Starch can be waxy, modified for more functionality or resistant, which can't be digested because it's composed of partly milled grains and seeds. As its name suggests, resistant starch resists digestion in the small intestine and passes through the body without entering the bloodstream or breaking down into glucose, as most other foods do.
Heat-stable in most conventional cooking operations, resistant starch can be used as an ingredient in a wide variety of conventional foods.
Used in practically all food starch applications, modified starches act as thickening agents, emulsifiers and stabilizers. Bonded with phosphate, modified starch can absorb more water and keep ingredients together. Modified starches are obtained from native starches as a result of physical, enzymatic or chemical processing methods.
Developed in the 1950s with the onset of fast and convenient foods, modified starches serve a number of functions. They offer superior thickening, increased paste clarity, stability in refrigerated and frozen storage, as well as resistance to mechanical shear, high temperatures and retort processing, and they improve adhesion and texture.
They can emulsify salad dressings by enveloping oil droplets and suspending them in liquid, such as vinegar. Acid-treated starch forms the shell coating of jelly beans. Oxidized starch increases the stickiness of batter.
Modified starches are often recommended for challenging process conditions (pH, temperature and shear) and longer shelf stability when developing unique and differentiated textures or cost-effective solutions, points out Marcelo Nichi, senior manager marketing texture at Ingredion (www.ingredion.com), Westchester, Ill. "Modified starch is used in different applications because of its functionality and process tolerance. It usually provides excellent cost-in-use, higher flexibility and breadth of applicability."
Modified starches also better withstand harsh thawing, pressure, heat and other processing rigors and help extend the shelf life of products. The major raw materials for modified starch include corn, tapioca, amylose, potato and wheat.
Native starches are untreated and include corn (dent or field corn, waxy maize, high amylose), potato and tapioca. All native starches are allowed for use in food, but the range of chemically modified starches is restricted for food use. The use of native starches from plants is on the rise, as food developers and manufacturers replicate the properties and functions of wheat for gluten-free applications, which hasn't always been easy to do.
"The increased use of native starch is driven by the development and promotion of clean label, functional starches, which are physically modified to alter their rheological properties," explains Mel Festejo, COO at American Key Food Products (akfponline.com), Closter, N.J. "These clean-label starches, being developed from corn, tapioca, potato and even peas, ultimately have enhanced functionalities."
Native starch is being added to bakery products, snacks, batters and breadings, says Angelina De Castro, Ingredion's senior manager of North America wholesome innovation. "Native starches can be used in canned products, processed meats, noodles and pasta and dry mixes. Rice, potato and tapioca starches are highly used in gluten-free products. But unmodified, native starches inherently have little process tolerance and break down easily under conditions of heat, acid and shear to yield very low viscosity and undesirable textures. They also have very poor freeze/thaw stability, resulting in either a grainy or a gelled texture with a lot of syneresis."