R&D: Microencapsulation for Natural Color Stability -- December 2010

As many consumers seek natural alternatives to synthetic food colors, companies are responding by choosing natural colors for new products and also by replacing the synthetic colors traditionally used in foods and beverages.

However, the use of natural colors can often be a challenge, says Byron Madkins, senior director, Product Development and Applications, Colors, Chr. Hansen. Many natural colors are susceptible to degradation, when exposed to various factors, such as heat, light, low pH and oxidation. The key to optimal performance of a color in a food application, whether synthetic or natural, is the selection of the most suitable and stable color formulation. With natural colors, one of the greatest challenges can be their stability. A color should maintain its starting shade and intensity for the duration of the food productís shelflife, Madkins adds.

In understanding the needs and challenges of product developers, as well as food and beverage product requirements, Chr. Hansen developed CapColorsÆ, a range of natural colors based upon microencapsulation technology.

One of the first priorities of color formulation is to successfully incorporate the pigment into a form or system that can then be suitably added into a given application. For example, turmeric pigment is sparingly soluble in alcohol and essentially insoluble in most other media, says Madkins. To make it water-miscible, it is emulsified, typically using polysorbate-80. While this works well, the emulsified turmeric eventually fades in applications exposed to light. It is here that microencapsulated turmeric has a big advantage. Experiments have compared emulsified turmeric to microencapsulated turmeric, in which both are used at 0.08% in a typical soft drink formula, which is then subjected to accelerated light conditions. The overall change in color is measured as Delta E, a colorimetric value that takes into account changes in shade and strength. Higher DE values relate to greater changes in the color. Emulsified turmeric products demonstrate a large degree of change throughout the study, mostly due to loss of color strength, as compared to the microencapsulated turmeric product (in this study, T-15-WSS-P), which has little to no loss in strength or change in shade, Madkins notes.

In another experiment, also using the typical soft drink formula, microencapsulated turmeric was compared to emulsified beta-carotene, emulsified carrot extract (yellow-orange) and, as a reference, FD&C yellow 5. The strengths were all adjusted to be comparable, both spectrophotometrically and visually. The samples were subjected to high-intensity light for eight hours. The microencapsulated turmeric performed best, even better than FD&C yellow 5, with minimal change in strength and shade, Madkins relayed. (See chart ìLight Stability of Microencapsulated Turmeric vs. Other Yellow Colorants.î) In a similar experiment under accelerated heat conditions (45∞C for 56 days), the microencapsulated turmeric beverage had the lower DE value compared to the other natural colorants and was, thus, most stable. In addition, it performed comparably to the FD&C yellow 5 sample under these conditions.

Using CapColor technology, Chr. Hansen is able to microencapsulate natural color pigments and provide high-stability, water-dispersible color formulations in liquid or powder form. This technology has been successfully applied to annatto, paprika, carmine, beta- carotene and chlorophyll. The end-result is a natural color range that has increased stability to light, heat and oxidation; has very good stability in a wide pH range (2.5-8.0); and provides bright and vivid shades in application. CapColors are suitable for any application that contains a water phase or that will be reconstituted, including confections, beverages, cereals, snacks, baked goods, coatings, dairy and dry mixes.pf

For more information:
Chr. Hansen Inc., Milwaukee, Wisc.
Byron D. Madkins, 800-558-0802
usbma@chr-hansen.com, www.chr-hansen.com