Starches
Pages 49-55
DOI: https://doi.org/10.1094/1891127012.005
ISBN: 1-891127-01-2
Abstract
Topics Covered
- General Considerations
- Sensory Considerations
- pH Considerations
- Formula-Related Considerations
- Processing Considerations
- Distribution and End-Use Considerations
- Starch-Selection Guides
Introduction to Chapter
The versatility of starch, particularly modified starch, makes it well suited for a wide variety of foods (Table 5-1). Starch contributes to texture, viscosity, gel formation, adhesion, binding, moisture retention, film formation, and product homogeneity. Certain modified starches are also being increasingly used as fat substitutes in low- and no-fat products.
Commercial starches are obtained from cereals such as corn, wheat, and various rices and from tubers or roots such as potato and cassava (tapioca starch). Starches from different sources vary in taste and viscosifying properties. For example, native potato and tapioca starches have weak intermolecular bonding and gelatinize easily to produce high-viscosity pastes that thin rapidly with moderate shear. Potato starch produces clear, viscous, almost bland pastes, which are used in products such as extruded cereals and dry soup and cake mixes. Tapioca starch produces clear, cohesive pastes that gel slowly over time. Native corn, rice, and wheat starches form opaque, gelled pastes that have a slight cereal flavor. High-amylose corn starches produce opaque, strong gels commonly used in gum candies. Waxy maize starch produces a clear, cohesive paste (1).
Because the pastes and gels produced by native starches are often cohesive (gummy) or rubbery, the functional properties of these starches are improved by modification. Different types of modification produce starches that are better able to withstand the heat, shear, and acids associated with various foods and food-processing conditions. Modification can have an effect on starch solubility, viscosity, freeze-thaw stability, paste clarity and sheen, gel formation, film formation, and cohesiveness.
There are numerous factors to consider in the choice of a starch for use in a particular food system. The desired properties of the food (e.g., texture, mouthfeel, and viscosity), the method of processing, and the distribution parameters, especially storage temperatures, must all be examined. An up-front strategy in which the various requirements of the food product are reviewed prior to selection of a starch saves time, frustration, and probably money in the product-development process.
