Hydrocolloids
Pages 55-65
DOI: https://doi.org/10.1094/1891127381.005
ISBN: 1-891127-38-1
Abstract
Topics Covered
- Improving Stability
- Heat Stability
- Separation Over Time
- Undesirable Crystal Growth Over Time
- Syneresis
- Dairy Products Containing Protein
- Creating and Improving Texture
- Thickening Agents
- Gelling Agents
- Improving Both Texture and Stability
- Improving Nutrition
Introduction to Chapter
There are many parameters to consider in the selection of a hydrocolloid for a food application. One of the most important is the cost-in-use of the gum in the application. However, this parameter is meaningful only if there is more than one hydrocolloid that can be used to successfully solve the problem. Table 5-1 provides a summary of common food hydrocolloids and the general classes of commercial food applications in which they are used. There is generally some flexibility in selecting a food gum for a given application, and quite often more than one gum will do the job.
When selecting a hydrocolloid for an application, the first question a food developer should ask is, “What do I expect the hydrocolloid to do for my application?” By clearly defining the purpose, you stand a much better chance of selecting the right gum for the job. The answer to this question should be one or more of the following:
- Make the product more stable over time (i.e., increase shelf life) or more stable under a specific set of conditions (such as high temperatures).
- Create, improve, or modify the texture of the finished product
- Improve both texture and stability
- Provide added nutrition (e.g., soluble or insoluble fiber).
Other questions that should be asked when selecting a hydrocolloid include the following:
- Does the product contain a significant amount of protein? If so, what type of protein is it (casein, whey protein, soy protein, other)?
- What is the pH of the product, and is the pH of the product higher or lower than the isoelectric pH of the protein?
- Is this an “instant” product the consumer will buy as a dry mix and rehydrate, or is it a liquid (“wet”) product?
- What are the soluble solids (degrees Brix) of the product?
- What is the nature of the stability problem the hydrocolloid should solve? Does the product:
- become unstable when heated (melt, run out, separate)?
- separate over time (fat, oil, or air rising or particulate matter, such as fruit pieces, spices, or cocoa powder, settling)?
- exhibit undesirable crystal growth over time (usually water or sugar crystals)?
- exhibit syneresis (“weeping” or “wheying off”)?
- contain protein that becomes denatured because of the low pH, high temperature, or the ionic strength of other ingredients?
The following discussion gives an idea of which questions to ask and in what order to ask them when selecting a hydrocolloid or combination of hydrocolloids for a food application.
