Starch is commonly used in many different types of food for a variety of purposes such as thickening, gelling, stabilizing, and as a replacement for more expensive ingredients. Starch is a favored ingredient in the food industry because it is readily available, relatively inexpensive, and has unique properties. The use of starch in food has a long history, dating back to ancient times. Over time, starch has been added to different foods, such as breads, beer, baking powders, pie fillings, sauces, jellies, puddings, and salad dressings, using various types of starches such as corn starch, tapioca starch, and locust bean gum.
First Enhancement of Starch for Foods
In the 1830s, large potato starch mills opened in Germany, and sweeteners produced by breaking down starch with acid were used to improve wines. Scientists like Naegeli and Lintner studied this process and discovered that it produced shorter molecules. Today, these types of starches are known as fluidity or thin-boiling starches. In the early 1900s, Bellmas and Duryea patented acid-thinned starches.
Modern Use of Starch in Foods
In the late 1940s, the US food industry used around 100,000 metric tons of starch annually, with only about 30,000 metric tons used in processed food. The brewing, baking powder, and confectionery industries were the leading users of starch at the time. By 1995, there was a ten-fold increase in the use of corn starch, modified corn starch, and corn dextrins in the US, with 2.6 million metric tons produced, and 950,000 metric tons used in food. In Europe, 5.1 million metric tons of starch were produced in 1989, with 60% being maize, 20% potato, and 20% wheat starch. Of this amount, 55% was used in food, as reported in 1992.
Development of Crosslinking
In 1943, a patent was issued for starch oxidized in the presence of protein after it was discovered that bleached tapioca flour with high protein content improved process stability in fruit pies. Cross-linking with bifunctional reagents, such as epichlorohydrin, phosphoryl chloride, and sodium trimetaphosphate, was first used in the late 1940s to make distarch ethers and distarch phosphates. These starches were widely used in various food products, including salad dressings, pies, canned vegetables, soups, sauces, and gravies. However, due to safety concerns for starch plant workers and the possible residual reagent in food ingredients, the use of epichlorohydrin in food starches was discontinued by the US corn wet-milling industry in 1978 via self-regulation.
Development of Monosubstitution
Acetylation was the first way to modify food starches. It was first used in waxy maize acetylated distarch adipates in the mid-1950s, to improve the stability of pie fillings during winter distribution. This was achieved by reacting the starch with acetic anhydride or vinyl acetate. Canned soup and sauce processors switched to modified waxy maize starch because of its improved smoothness and sheen. The improved freeze-thaw stability of acetylated crosslinked waxy maize starch led to the marketing of frozen sauces, initially on vegetables, but also in entrees and pies by the 1960s. The use of hydroxypropylation was commercialized in the early 1970s, which improved the stability of puddings and frozen sauces. Encapsulation with emulsion-stabilizing dextrins began in the mid-1960s, and corresponding modified food starches for use in beverage emulsions came into use in the mid-1970s.
“Instant” Starches
Starches that are drum-dried, cross-linked, and stabilized were developed around 1960, allowing for the creation of instant dessert mixes and in-plant cold processing of starch-containing foods. In the 1980s, granular starches that could swell in cold water were developed, leading to much higher quality in instant desserts and cold processing of dressings and other foods. These starches were prepared by spray drying and hot aqueous ethanol treatment.
Improvement of Starch Sources
Waxy corn, a type of corn with high amylopectin content, was discovered in China in 1908. Although initially considered a genetic curiosity, its properties were found to be similar to tapioca starch. Interest in waxy varieties of corn, barley, rice, and sorghum increased during World War II when access to Southeast Asian tapioca supplies were interrupted. Waxy sorghum and maize were developed for production in different states, and commercial production of waxy maize began in the mid-1940s. Unique starch properties were observed in maize double mutants involving the waxy gene and other loci. High-amylose starch was developed in the 1950s and became commercially available in 1958.