Getting to the Root of Tapioca Starch

Say tapioca to consumers anddepending on whether they favor comfort food or trendier farethey picture translucent, slippery pearls in tapioca pudding or bubble tea. Say tapioca to food scientists and they think of a unique, valuable stabilizer.

Digging up background

Tapioca starch is derived from the root of the cassava, or manioc, several different tropical plants that belong to the family Euphorbiaceae (Manihot species). According to Prescott Bergh, director, sales & marketing, Ciranda, Hudson, WI, the plants are native to Brazil and have spread to other regions, notably Asia. The roots contain approximately 20% to 32% starch. Manufacturers use wet-milling to extract the starch.

Tapiocas round granules range from 5 to 25 microns, compared to 5 to 20 microns for corn starch and 15 to 75 microns for potato starch, says Wen Shieh, technical leaderconfection, beverage, fruit preparation, Cargill Texturizing Solutions, Minneapolis. In general, the larger the starch granule, the easier and faster it swells.

The granules consist of approximately 17% amylose of high molecular weight, which falls in the same general amylose-to-amylopectin neighborhood as other root-derived starches. Tapioca is unique in that it is an amylose-containing starch, but its properties are different from starch made from regular dent corn or waxy corn, says Eric Shinsato, technical sales support manager, Corn Products U.S., Westchester, IL. Regular dent corn contains approximately 25% amylose and forms a rigid, cuttable gel. Waxy corn starch contains virtually no amylose and is cohesive in texture and does not gel. Tapioca starch forms a paste instead of a gel.

Native tapioca starch gelatinizes around 59ºC, which is 10ºC to 15ºC lower than native waxy corn and common corn starch, says Shieh. This lower gelatinization temperature can provide some energy cost saving when preparing starch paste.

Pearl tapioca, the form used in puddings and bubble teas, looks like small pearls and requires soaking in water before cooking. Like other commercial starches, tapioca is available in native or modified forms. Typically, the modification methodsphysical and chemical used for corn starch can be applied to tapioca starch and make the modified tapioca starch more process-stable and also provide desired functionalities, observes Shieh. Crosslinking makes the granules more resistant to shear; acetylation decreases gelatinization and pasting temperature, and increases solubility and swelling power. Hydroxypropylated versions have excellent freeze/thaw stability.

Tapioca produces a translucent, glossy appearance and has a bland flavor. Of the commonly used starchescorn, potato, wheat, etc.tapioca is very bland in taste and is well suited for mildly flavored applications, says Shinsato.

Native tapioca is a popular choice for natural and organic foods, says Bergh. Its non-GMO and non-allergenic, and from a processing standpoint it gives a more-stable end product with a uniform consistency and a better flavor profile.

When used as thickeners, tapioca starches give similar viscosity to comparable corn starches and are typically used at similar levels, says Judith Whaley, senior research manager, National Starch Food Innovations, Bridgewater, NJ. There are also specialty tapioca starches that exhibit unique textural characteristics in low viscosity applications, allowing for consumer-desirable benefits related to mouthfeel. These specialties are distinctive in that they offer unique sensorial experiences in beverage and dairy applications without contributing viscosity.

Tapioca starch is uniquely suited to address several specific processing- functionality and consumer-acceptance needs. The ability of tapioca starches to help in delivering low hot viscosity and reduced burn in HTST (high temperature short time) processing is one example, notes Marshall Fong, marketing director, National Starch. Contributing appropriate levels of intensity in the textural components of mouthfeel linked to higher consumer acceptance is another area where tapioca starch is ideal. This is especially true in dairy applications, because it also improves overall taste.

Teaching tapioca new tricks

Tapioca can also be converted to resistant starch for fiber fortification. Cargill markets an 80%-fiber tapioca resistant starch with a low water-holding capacity. It permits high levels of inclusion in baked products, without creating a gummy texture or altering the taste of the finished products.

Tapioca can aid gluten-free formulations, too. Corn Products created a specialty tapioca starch, Expandex , that provides expansion and stability in gluten-free baked items, without using gums. It is different from resistant starch, as it is not a source of fiber, says Shinsato. Expandex is not a one-for-one replacement of wheat flour, but is used in conjunction with non-gluten containing floursrice, sorghum, potato, bean, etc.to improve the texture and the overall quality of gluten-free bakery products.

Applications include oven and bread machine mixes, pizza crust, cookies, waffles, muffins, wraps, quick breads and breaded meat products. When using Expandex, product developers need to closely watch the amount of liquid used and the total amount of protein in the formula, to achieve maximum benefit, he says.