How Spectrophotometers Measure Caramel Color Additives: Using the Hue Index for Analysis

For years I have been buying wheat bread as a healthier alternative to white bread, but recently I learned that the rich brown color that I’ve come to associate with whole grains may simply be a caramel color additive that is used to manipulate consumer perception. Well, it works! My own personal preference has not changed, despite the knowledge that two products may only vary in color. My visual perception directly affects my taste and I still lean towards the rich brown color that my brain has grown accustomed to.

Manufacturers are also aware of the important role that color plays in consumer choice. Color additives serve a very important purpose in today’s food industry, and food and beverage companies must find ways to appeal to both the oral palette as well as a visual one. Caramel color is highly effective in altering the color composition of many foods, and spectrophotometers offer the ability to accurately measure color changes as caramel color is added. In doing so, manufacturers can achieve the desired appearance that consumers demand, and with consistent results each time.

The advantages of caramel color additives

Many processed food companies rely on caramel color to enhance their product appeal because of its affordability, manufacturing ease, and availability. Due to its mild flavor and a bland aroma, caramel color does not significantly impact the taste or smell of the finished product. It is used in a variety of products such as soft drinks, baked goods, seasonings, pet foods, soups, coffee products, syrups, and more.

In addition to the high desirability of caramel color, it is also preferred as a more natural alternative than other food color additives and does not carry the same regulations that are associated with artificial color choices. The FDA (Food and Drug Administration) identifies caramel coloring on its list of color additives exempt from certification, as long as the additive adheres to the specific criteria as stated:

1. The color additive caramel is the dark-brown liquid or solid material resulting from the carefully controlled heat treatment of the following food-grade carbohydrates.
2. The food-grade acids, alkalis, and salts listed in this subparagraph may be employed to assist caramelization, in amounts consistent with good manufacturing practice.
3. Polyglycerol esters of fatty acids, identified in 172.854 of this chapter, may be used as antifoaming agents in amounts not greater than that required to produce the intended effect.
4. Color additive mixtures for food use made with caramel may contain only diluents that are suitable and that are listed in this subpart as safe in color additive mixtures for coloring foods.

As long as this criteria is met, caramel color can be used safely and effectively to enhance the visual appeal of food products. However, it is necessary to monitor these steps carefully to ensure proper use of additives and effective measurement of color during the heating processes.

Color Measurement and the Hue Index

Caramel coloring is often measured using a ratio of absorbance values through spectral analysis. These measurements are then used for evaluation using a method called the Hue Index, which usually ranges from 3.4 (very dark walnut brown) to 7.5 (amber red brown) for caramel colors (0.1% solution). This method has various uses, and is heavily relied upon for the measurement of tea products and beer brewing color variations as well.

Manufacturers in the food industry are looking for a caramel color supply that exhibits color strength and compatibility with other ingredients. Several factors influence color measurement and consistency, as well as compatibility according to the desired application. Factors such as pH, positively and negatively charged ions, and product consistency (wet or dry product batches) all influence product needs and compatibility, and require advance spectrophotometers for accurate measurements. Time also influences caramel coloring, as it tends to darken with age, making constant monitoring and analysis a necessity.

Color Measurement Instrumentation

For the measurement of the variations in caramel color products, spectrophotometric instrumentation needs to be designed to manage various sample batches, wet or dry product samples, and a variety of viscosities. HunterLab offers an assortment of instrumentation options designed for each individual market need to accommodate a variety of sample batch sizes and consistencies. Our experienced staff is here to help you choose the right instrumentation designed to meet your specific budget and application requirements. Contact HunterLab today to learn more about how color measurement can create uniformity and stability in your color additive products and applications.