Exclusive: How to select starch ingredients, part 2
Feb. 13, 2013
by Laurie Gorton
Expert from Roquette America offers insight into the functional advantages of starches.
Food starches bring many different functional advantages to baked foods and snacks. In this exclusive Baking & Snack Q&A, Carl Jaundoo, PhD, associate program coordinator, Roquette America, Inc., Keokuk, IA, examines native and modified starches from the standpoints of ease of use in processing to texture effects in finished products.
Baking & Snack: How do native starches differ in applications in baked foods and snacks?
Carl Jaundoo, PhD: Starches contain two basic molecules, amylose (mostly linear chains) and amylopectin (highly branched chains). Corn starch has about 25 to 28% amylose while high-amylose corn typically contains about 50 to 70% amylose. Waxy maize has virtually no amylose. The ratio of amylose to amylopectin influences the functionality including gelatinization temperature. When starches are heated, the linear molecules, amylose, solubilize and leach into solution. This follows by reassociation, aggregation and finally precipitation at low concentrations. Waxy maize, with no linear molecules, remains flowable and clear.
Native starches are insoluble in cold water and must be cooked to obtain maximum functional benefits. This requires critical process control because there is often a narrow range of tolerance between undercooked and overcooked. The functionality of native starches is also affected by process conditions such as mixing, shear, pH and baking time and temperature.
Today, bakers can select from among a number of modified starches that can meet the most challenging process conditions without loss of functionality. Modified starches are also more forgiving to variations in processing compared with native starches.
What characteristics of specific native starches most benefit these food uses? Why?
Native starches are most suitable for products that are freshly prepared and used without prolonged storage. Based on the source, the functionality of native starches varies from a heavy bodied paste (maize) to high viscosity, long texture, creamy consistency and low temperature stability (waxy maize.) High-amylose maize starch typically exhibit high gelatinization temperature (above 120 degrees C), short texture and firm opaque gels.
Food products cover a wide variety of textures, distribution channels and shelf life. Based on these considerations, starches can be used to formulate products across the spectrum without compromise in taste.
What benefits do modified starches bring to bakery formulations?
Starches are modified to provide functional benefits including tolerance to differing processing conditions such as high-shear mixing, pH conditions, baking time and temperature and shelf life.
When should a formulator consider a modified starch over a native starch?
Native starches are good thickening agents; however, their functionality can be affected by other ingredients such as sugar and fruits with low pH. In these applications, sugar and pH conditions will affect adversely the thickening power of native starches. To overcome the loss of starch functionality, modified starches are designed to function over a wide range of processing and storage conditions.
What is the most important trend in use of starches by bakers? Why?
Among the drivers for the bakery industry, like the rest of the food industry, is the focus on clean labels. This trend will influence the choice between modified and native starches, with more bakeries looking for native starches with the same functionality as modified starches.
How do you see the applications for starches changing in the next few years?
Starches are cost-efficient functional ingredients. They influence appearance, texture and taste and shelf life. With such a wide range of functionalities, the role of starches is expected to increase as new developments in starch technology expand.
Usually crop conditions have little impact on ingredients such as food starches, but 2012 is an unprecedented year, especially with respect to the US corn crop. Do you think the US drought will affect availability of food starches? If so, what are you advising your starch customers about supply and alternative ingredients? If not, why not?
Roquette does not expect the current US corn situation to impact the availability of corn starches and corn-based food ingredients. This year’s drought has reduced the yield, quality and size of the US corn crop in unprecedented ways. However, the proportion of the US corn crop dedicated to producing food ingredients is relatively minor when compared with other uses such as animal feed, ethanol and exports to other countries. Significantly higher corn prices have already impacted the overall demand for corn, and additional rationing is expected in other sectors. The raw material costs for corn-based food ingredients are expected to increase significantly, but at this time, we do not expect difficulties with availability.
What food starches does Roquette America provide for bakery and snack use?
Roquette offers native and modified starches for bakery and snack foods including starches made from wheat, potato, corn, tapioca and yellow pea.