Specialty starches: A processor's best friend

They meet a multitude of processing needs and consumer preferences in many food applications

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.

Resistant starch

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.

There are four types of resistant starches:

* RS1 , Physically inaccessible and found in partially milled grains, seeds and legumes.

* RS2 , Naturally digestion-resistant and found in plantains, raw potatoes and high-amylose corn.

* RS3 , Retrograded or crystalline non-granular forms and found in cooked and cooled potatoes, bread crusts and cornflakes.

* RS4 , Chemically modified or re-polymerized starch with altered chain linkage.

Because RS does not absorb a lot of moisture, it does not adversely affect food quality or texture and is therefore popular as a functional dietary fiber. A noteworthy RS in the market is FiberStar 70 from MGP Ingredients Inc., Atchison, Kan. Produced from wheat, the starch enhances fiber content in products, including low-carb foods, and does not detract from the taste.

 

National Starch optimized the physical structure of starch to create Novelose, recently renamed Hi-maize. This natural ingredient derived from corn can deliver the health advantages of fiber to foods without changing the taste or texture. Hi-maize is rich in fiber and has prebiotic properties to optimize digestive health.

Resistant starches add significant dietary fiber content to foods and lower the net carbohydrate count and glycemic response.

The National Institutes of Health report RS is practically indigestible and does not contribute any calories because the body cannot absorb it. In taking advantage of this concept to create low-carb foods, food product developers opened the paradoxical market for RS -, as a healthy standout in the carbohydrate category.

Starch industry expert Sakharam Patil of Munster, Ind., attributes growing demand for RS and SDS starches to the rising inclination of food companies to develop low-carb fare. "Practically every major food manufacturer is exploring low-carb options but only two RS starch manufacturers have any capacity to consider."

Cold water-swelling

Specialty starches labeled instant, granular or cold water-swelling hydrate at lower temperatures and eliminate the heating step. In addition to convenience and significant savings in time, labor, energy and equipment, these also improve the quality of delicate products normally harmed by heat.

Tate & Lyle, Decatur, Ill., employs innovative technology to disrupt the internal crystalline structure of starch granules to allow for hydration or viscosity development without cooking. The resulting line of ingredients ,- Lo Temp 452 and 588, Mira-Gel 463, Mira-Thik and Mira-Sperse starches -- offer the quality of a cook-up starch without typical cooking temperatures.

Paying close attention to the step-by-step processing needs of food manufacturers helped create highly tailored functionalities and unique applications, according to Mike Bunch, associate food scientist at Tate & Lyle. For instance, Mira-Sperse 2000 swells slowly in cold water to allow ease of dispersion without diluents, it then holds and manages more water, making it ideal for extending the shelf-life of baked products. Mira-Gel 463 offers a "clean label" option for ambient temperature hydration and gelling applications.

The market demand for convenience prompted Scandinavian starch producer KMC to create ColdSwell starch, made with patented technology that cooks the starch without disrupting the granules. ColdSwell binds liquid and creates smooth texture in mayonnaise-like products. It also is an alternative to drum-dried instant starches for dry mixes such as cup-of-soup products and sauces, which only require limited heating for preparation.

Penford Food Ingredients Co., Denver, focused on creating specialty starches for robust freeze-thaw stability at low usage levels for a variety of frozen soups, sauces, and gravies. The company's modified tapioca starches have clean taste and hold up extraordinarily well in gravies and sauces in steam table conditions, according to Jeff Smith, director of business development. The company's new line of substituted waxy maize starch imparts gloss and sheen in addition to withstanding cold storage or frozen situations.

For organic and natural foods

Until fairly recently, starch choices were limited for developers of organic foods and beverages. Manufacturers of these foods must explore specialty ingredients for viable options to meet the rigors of increased production and distribution.

Modified starches are avoided in principle because of controversial connotation of chemical modifications. "Agrana Zucker und Starke [Austria] addressed this market need early," notes Grace Marroquin, principal and organic ingredient specialist at Marroquin International, Santa Cruz, Calif. "They manufactured several organic starches -- including organic native and pregel starches from corn, waxy maize, and potato -- to allow for the production of organic food products that do not require heat for preparation."

But organic food processors also must produce attractive food products with appealing textures. For that challenge, National Starch offers Novation, a series of unmodified food starches with high processing tolerance. Five products in the line have been approved for use as "organic" or "made with organic ingredients," but not "100 percent organic." Also, Novation may be labeled as "cornstarch" or "tapioca starch."

Limited technology expertise in the organic manufacturing sector is an opportunity for mainstream suppliers. New regulations on organic labeling from the USDA create additional opportunity for clean label specialty starches. The National Organic Program is approving a series of ingredients and processes in anticipation that growth in the organic sector will surpass organic raw material supplies.

Meanwhile, commercial processors will continue to rely on innovation and specialty starches for specific needs. The Code of Federal Regulations has made some changes to accommodate specialty starches in recent years, and industry insiders anticipate more.

Nevertheless, emphasis on new methods rather than on chemical modification to produce specialty starches promises a future with even more healthier and less expensive specialty starches as viable means to creating nutritious and affordable foods that taste good.

Kantha Shelke is a principal at Corvus Blue LLC, a Chicago-based firm that specializes in competitive intelligence and expert witness services. The firm helps businesses and professional organizations in the health and wellness sector to focus on what matters most. Kantha may be reached at kantha@ais.net or (312) 951-5810.

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