Modern food processing demands formulations with established proportions of ingredients and strict adherence to set conditions. Slight variations in ingredient quality or functionality can lead to noticeable differences in the final product. Food product developers also are challenged when modifying formulations for functional or nutritional enhancements.
Starches serve as a wonderful "catch-all" ingredient, and one that helps make formulations more forgiving. The wide variety of starches and their natural properties , as well as the ability to alter those properties -- make starch a veritable boon to the food industry.
Cooks and food product developers for generations have relied on starch to bring about aeration, crispness, dispersion, film formation, gel formation, heat and freeze-thaw stability, moisture-binding, pH control, suspension of solids, texture, viscosity, and volume control in foods and beverages. Few other ingredients offer the range and versatility of characteristics as silently and economically as starch does.
A new class arises
A new class of ingredients loosely called specialty starches emerged in recent years by taking advantage of the concept that the properties and therefore the functionality of starches could be manipulated.
Specialty starches evolved from selective separation and modification. They meet a multitude of processing needs and consumer preferences in a wide array of food applications. Today practically every food processor uses specialty starches as problem-solving ingredients to improve the cost, quality and performance of the finished product.
National Starch's Hi-maize resistant starch increases dietary fiber content in bread without changing the taste or texture.
Specialty starches currently represent approximately 60 percent of the U.S. food starch market in volume, but 80 percent of the market's value , meaning specialty starches in 2003 fetched more than $400 million, according to IMR International, San Diego. Total sales figures for all types of starches were flat in the past decade, but the unique properties of specialty starches helped them gain significant market share. Specialty starches grew an average of 3% annually. Further, the resistant starch and organic sub-segments experienced double-digit growth in 2003.
Consistency and convenience associated with specialty starches allow for commercial preparation of foods that once were made only from scratch. They also have assisted the proliferation of new products in the retail take-out meal solution and foodservice sectors, which in turn escalated the demand for specialty starches.
Key market drivers include efficiency in food processing, consistency in product quality, the escalating appeal of clean labels and, more recently, growing awareness of obesity and consumer demand for wholesome foods.
The momentum behind specialty starches is expected to continue due to increasing demands for convenience and nutrition and the growing interest in value-added ingredients.
What's so special?
Regardless of the source, starch contains amylose and amylopectin. Both are polymers of glucose molecules, with distinct properties and functionalities. Slight changes in their ratios and their physical or chemical structures can lead to considerable changes in their range of functional characteristics.
Based on application, botanical source or how they were processed, food starches may be classified as powdered food starches, modified food starches, pre-gelatinized or instant starches, granular cold water swelling (CWS) starches, and functional native starches. Labeling requirements for starch products from the FDA (covered under 21 CFR 172-892) demand expertise for meticulous match of functional property with the processing or application need.
Starch granule size affects the functionality of the specialty starch. Oat starches (left) have small granules (approx. 25 microns) that provide a distinctive oat flavor and light-brown color. Potatoes (right) offer very large starch granules (greater than 100 microns) that are highly viscous when cooked and lend a gold to light-brown color to food. Corn (not shown) has medium-sized granules (approx. 35 microns) that give a definite corn flavor and yellow color.
Specialty starches are made by manipulating the proportion of the constituents, modifying the hydroxyl groups, or by selectively separating the granules on the basis of size or other functional attributes for concentrated features and enhanced effectiveness in food systems. These may be achieved chemically, physically, genetically or by a combination of these methods.
National Starch has developed functional native starches that provide the shear, pH, and heat tolerance characteristics of modified starches but with clear labeling advantages. These starches, which are made using patented, proprietary physical processing methods, may be labeled simply as "starch" rather than as "modified food starch."
Specialty starches successfully differentiated themselves from mainstream starches because manufacturers diligently identified customer needs and tailored products to match them. The abundance of economical raw material certainly helped.
Recent notables in the marketplace include resistant starches that analyze as dietary fiber and indigestible carbohydrates in low-carb foods, cold-water-swelling starches that mirror the properties of cook-up starches with cost and processing advantages, and functional native starches with the functionalities of modified starches but with a labeling advantage.
In nature, starches are nutritional energy sources with a few exceptions. Nutritionally, starches may be classified as rapidly digestible (RDS), slowly digestible (SDS), and resistant starch (RS). The SDS and RS starches do not convert to glucose and raise blood-sugar levels the way RDS starches do.