By Steve Smith, Contributing Editor
Since the marketplace is constantly evolving, food technologists must find solutions for ever-changing problems and demands. One current market need is for effective texturizing stabilizers in food systems. Although corn and potato starches are often used for this purpose, there are other novel sources, such as tapioca (also called cassava or manioc), that can be applied to an array of foods.
Tapioca starch elements
Tapioca starch is extracted from the root of the cassava plant, cultivated in tropical areas worldwide, including Southeast Asia and South America. Starch comprises about 25% of the cassava plant and is its main constituent. Cassava starch is produced primarily by the wet milling of fresh cassava roots. The extraction process can be divided into five main stages: preparation (peeling and washing), rasping/pulping/grating, purification (starch washing), dewatering and drying, and finishing (milling and packaging).
Typically, tapioca starch contains about 17% to 20% amylose. The starch granule sizes range from 4 to 35 microns. Tapioca starch has many favorable characteristics, including high paste viscosity and clarity, and high freeze/thaw stability. It has a bland, clean flavor and can be used in foods with delicate flavor requirements. It can be precooked or pregelatinized to make cold-water-swelling or instant starches, and tapioca starch can be modified in accordance with FDA regulations (Title 21 of the Code of Federal Regulations, Part 172, Section 892).
Tapioca starch is used in a variety of food applications, including soups, sauces, gravies, bakery fillings, cheese, gluten-free bakery products, dairy products and coatings systems. As is true with other botanical sources of starch, tapioca starch is available in its native form or in modified form. Modification of tapioca starch is directly dependent on the specific food application and the accompanying process conditions. Starch modifications can address processing conditions such as low pH, high shear and freeze/thaw requirements.
Dairy products, soups, sauces, gravies and bakery fillings can use starches modified by hydroxypropylated (HP) or acetylated (AC) processes. HP tapioca starches provide viscosity, process stability (i.e., shear, heat, low pH, retort), and freeze/thaw stability. AC tapioca starches provide similar benefits, but to a lesser degree in extreme food processing conditions. The usage level of modified tapioca starches in these types of food applications ranges from 3% to 6%.
When it comes to formulating gluten-free products, there are several challenges that affect product attributes, including dough viscosity, finished volume, structure and shelf-life stability. Without gluten in the formulation, all three of these attributes are affected negatively. Gluten-free baked goods use blends of modified tapioca cook-up starches to create volume and structure, minimize dough stickiness, and improve freeze/thaw stability. Most importantly, modified tapioca starch blends retain moisture in gluten-free bakery products. This reduces retrogradation and, as a result, staling is minimized. Since shelf-life stability is a major hurdle in gluten-free product development, minimizing the staling process is key.
Currently, most gluten-free products are sold frozen because of shelf-life limitations. The usage levels of tapioca starch in gluten-free baking can be up to 30%. Gluten-free baked goods also use native and/or modified tapioca pregels to improve dough viscosity, which is important during the depositing step of the bread process. There is less spread and, as a result, improved finished bread structure.
Due to casein’s pricing, starch blends are often used to replace a percentage of cheese casein. Removing casein negatively affects cheese’s shredability, melt and stretchability. However, blends of modified tapioca cook-up starch can be used to partially replace the casein without adversely affecting the shred, melt and stretch attributes. These blends can be adjusted or customized to provide the targeted degree of melt and stretch. For example, some imitation cheeses require a long stretch, such as those used for pizza topping.
Finally, modified tapioca starches in combination with modified potato starches and tapioca dextrin can be used in coatings systems for various food products, such as french fries. Modified tapioca starches form a film and interact with the tapioca dextrin to create a crispy, tender french fry. The film coating also extends the time the product will retain its crispiness, flavor and other favorable characteristics.
Tapioca starch does have its limitations in certain food systems. The starch paste may exhibit some color, which is not optimal in white or light-color sauces or pie fillings. The cooked tapioca starch also produces a sheen or gloss that may not be desirable in some products, such as home-style gravies.
The tapioca edge
Tapioca starch has niche benefits in select applications, and it has advantages over other starches from different botanical sources. There are natural, non-GMO and/or organic sources of tapioca starch that can be used in formulating natural and/or organic food products for the U.S. market. Tapioca is not known to be allergenic; therefore, it is favored over corn starch in specific food markets, especially the gluten-free market. Tapioca starches are thus excellent texturizing and/or stabilizer options for the gluten-free market.
Because of its origin and relatively limited availability, tapioca starch has historically been more expensive than corn starch. Therefore, tapioca starch is not typically used as a direct replacement for corn starch. However, when availability of other botanical starches becomes limited, as has occurred in the corn and potato starch markets, modified tapioca starches can be used as substitutes, with some reformulation.
Native and modified cook-up and pregel forms of tapioca starch have generally the same legal use rules as other food starches used in the United States. In terms of labeling, if tapioca starch is in cook-up or pregelatinized form and is not modified, it can be labeled as “tapioca starch." If the tapioca starch is in cook-up or pregelatinized form and is modified, it is labeled as “modified tapioca starch" or “modified food starch."
Steve Smith has worked in the starch industry since 2004, when he joined Penford Food Ingredients as R&D manager. His current area of focus is starch application development in the protein, soups, sauces, gravies, dairy and coating systems market segments. Smith earned his undergraduate degree from Purdue University and holds an MBA from DePaul University’s Kellstadt Graduate School of Business. Contact Smith at firstname.lastname@example.org. Penford Food Ingredients Co., a division of Penford Corporation, founded over 100 years ago, is a global supplier of food and industrial starches. For more information, visit penfordfoods.com.