KANSAS CITY — When thinking about using natural colors in baked goods and snacks, it’s easy to get hung up on the limitations these additives have compared to their synthetic counterparts. In some ways, it’s true. These ingredients — which aren’t labeled as natural at all — need to be formulated with care to ensure stability and vibrancy. These colors are often extracted from plant sources like paprika, turmeric, beet, sweet potato, radish, red cabbage, spirulina, annatto, caramel, carrots and beta-carotene. Each comes with its own pH, moisture and sugar content, and even flavors and odors.
“Color plays an important role in making bakery products tempting to eat,” said Susan Frecker, senior application scientist, Oterra. “Achieving vibrant colors using naturally sourced colors rather than using those from synthetically derived FD&C dyes can be a bit more challenging.”
Many staple synthetic colors, however, have been delisted, and consumers’ demand for natural ingredients persists, leaving bakers and snack manufacturers turning to the ever-growing palette of naturally derived colors. The science of natural colors, officially identified by the US Food & Drug Administration as colors exempt from certification, is catching up.
“Natural colors have improved a lot in the last few decades because the growing cultivar selection for raw materials provides increased pigments as well as increased levels of co-pigments that naturally stabilize the color,” said Jeff Greaves, Eastern US and international sales, Food Ingredient Solutions. “Through processing improvements, we’re able to make stronger colors, and then there has been some work to introduce new colors: blue from the jagua fruit and butterfly pea and apple juice brown as an alternative to caramel. There are quite a number of them.”
While many colors can become muted because of low heat tolerance or light sensitivity, a multitude of options allow bakers to find one that works for their application.
“When you work with natural colors, there’s a broader range,” said Emina Goodman, senior director, commercial color development, ADM. “For example, in synthetic colors for yellow, you have Yellow No. 5. If you want to look at natural and botanical options for yellow, you have safflower, turmeric, beta-carotene and annatto. The challenge isn’t that they aren’t stable. The challenge is choosing the right color for the right system.”
Finding that appropriate color source requires understanding the application’s needs from processing to display as well as the different natural options available.
A reliable hue
The main challenge formulators face with exempt colors is their stability: their ability to remain vibrant and consistent through processing and the product’s shelf life. Heat, light and even fat content can all impact stability, but it’s based on the color and the formulation’s pH. Any tip in a color’s pH, and the hue can change, either by a little or a lot.
“Our first question when working on a new project is ‘what is the pH?’” Ms. Goodman explained, highlighting its importance. “Some botanicals naturally become very unstable when you shift the pH, so that is a key component.”
And this is where the exempt colors come into play. Not all colors behave the same, making certain raw material sources or color hues better suited to certain applications.
“A lot of colors in the pink to purple range come from anthocyanins, which are pH sensitive and can change color based on pH,” explained Alice Lee, applications manager, GNT. “In the bakery and snack space, applications can have a higher pH than other food categories. With a yeasted bread or tortilla, the pH might be 4.5, giving you a bright pink or purple, while a higher pH would create a more blue-ish purple.”
This is why understanding the pH sensitivity of the color is so important as well as the pH of the formulations. For example, chemical leavening agents can increase the pH of a dough when they are present, and that impact on color can be dramatic.
“Chemical leavening agents use an acid-base reaction during baking, which creates carbon dioxide gas to aerate and lighten doughs and batters,” said AnnMarie Kraszewski, application scientist, Oterra. “As a result, they increase the pH of the dough and may cause anthocyanins from fruit and vegetable juices to shift shade from red to blue.”
Heat can also have a detrimental effect on a color, which is an issue for bakery and snack products that may endure high temperatures in an oven, fryer or extruder. But again, some colors handle heat just fine, and bakers can push the limits when creating the most statement-making bakery items.
“Some color hues are really optimal for high-heat bakery applications like yellow, brown, oranges and pinks,” Ms. Lee said. “But sometimes people want really saturated color like rainbow bagels or intense black or red.”
Bakers have a few options when working with more heat-sensitive colors or when they are trying to get extremely saturated color. They can switch to a color that has been bred at the source to be more heat resistant.
Oterra, for example, developed its Hansen sweet potato to be less sensitive to heat and pH changes, providing formulators with an alternative to beet-sourced colors, which typically are sensitive to changes.
Bakers can also adjust their processing by baking for longer at lower temperature.
“Bakers using our anthocyanin-rich Suntava Purple Corn Extract Powder, Flour or Meal have found that slight adjustments to the cook time and temperature can help them achieve their desired color,” said Terry Howell, Suntava Purple Corn ingredient expert for Healthy Food Ingredients.
When working with a high-saturation product and the process can’t be changed, formulators can use a higher dosage of color. That will require, however, formulation changes as adding more color is never just adding more color when it comes to botanically sourced ingredients.
Shades of formulating
These food additives are sourced from botanicals, which means they bring to a formulation not only their own pH but also sugars, moisture and flavors, which can all have an impact on the ingredient system. Just as these colors can have an impact on the whole formulation, other ingredients can also impact color.
“Consider including the natural colors in the initial regulatory review and prototype development process,” Ms. Frecker said. “Optimizing the baked product’s pH, leavening system, baking time and temperature, and flavor from the start will help to improve the probability of launching a successful product.”
Acid, sugars and moisture from the colors could all have an impact on the finished baked good and require adjustments either in the formulation or the process to bake out added moisture. For example, the leavening system may need to be rebalanced to accommodate any extra acid from the color ingredient, Ms. Frecker explained. This will optimize crumb texture, but bakers also might need to reevaluate the leavening system based on the dosage of color.
“Correcting for added moisture contributed from a liquid color will also ensure the formulation performs well,” Ms. Kraszewski added.
Any extra moisture will need to be baked out or other liquids will need to be adjusted to prevent absorption or shelf-life issues down the line.
The various fruits and vegetables lending their colors to baked goods also come with a lot of sugar and starch, both of which provide functionality in baked goods. ADM uses its proprietary technology to extract sugar and starches before concentrating the color pigment without these extra ingredients that could impact the ingredient system.
Dispersibility is another component formulators will want to consider when choosing an exempt color. Whether or not a color ingredient is water- or oil-soluble will help steer bakers in the direction of what kind of color to choose.
“In the case of compound coatings or chocolate, oil soluble colors are used to give a uniform color,” Ms. Kraszewski said. “If adding natural colors to a frosting, adding a water soluble color to the water portion first allows for ease of use and prevention of specking.”
Blue and red colors that are sourced from spirulina and vegetable juices like beet, sweet potato and radishes are all water-soluble. Oterra developed a line of oil-soluble and oil-dispersible colors for those applications that cannot use water-soluble colors. Encapsulated colors can also provide more concentrated colors with improved solubility.
Oil-soluble colors are important for those formulations that contain a lot of fat, like icings. By supporting the emulsion of water and oil, cakes remain moist while colorful and colors from the icings don’t bleed into the cake.
“If the icing is just a powder, sugar and flavor, we can use standard liquid color, but if you have butter in it, you have more fat, so then you need an oil-soluble color,” Ms. Goodman explained. “You need the emulsion that gives you the brightness so you don’t have the bleed from the icing into the cake.”
When working with colors derived from sources such as beets, cabbage and paprika, the obvious question is whether these colors will impart a flavor or odor to the finished product. Food scientists are finding ways to protect finished product from these unwanted flavors and odors.
Oterra’s Hansen sweet potato, for example, contributes less flavor than beets in highly colored products like red velvet cakes.
ADM has worked on breeding out taste and smells but also developed its deodorized technology that not only concentrates the color but also removes unwanted odors and taste.
When trying to build up a vibrant color, bakers can also look to other ingredients in the system to build that color or potentially reformulate to help neutralize the base color so they don’t have to rely solely on a high dosage of the color additive.
“Sometimes we call it the base color, which is the color of the formulation without color, and it can be helpful or a barrier to reaching the desired color,” Ms. Lee said. “With red velvet cake, for instance, everyone wants an intense red on a dark chocolate base. But do you need that dark base, or can you reformulate by using some flavor to reduce the cocoa powder for a lighter color batter?”
Red velvet cake is one of the barometers for the vibrancy and efficacy of a natural color. The intensity of the color and the high pH level of a cake batter come together to make this a tricky application.
“The biggest challenge has been to make a nice stable red color for red velvet cake as a replacement for red 40,” Mr. Greaves said. “Of course, carmine works well for red velvet cake, but not everyone wants to use it because it’s not vegan or kosher.”
Carmine is considered a natural color as it is derived from the cochineal insect, but being an insect means the carmine color additive is off-limits to achieve a kosher or vegan label. Instead of carmine, bakers can turn to radish, red cabbage, beets, paprika and even sweet potatoes. Even when one color additive is determined to work, it might not work in a different formulation or a different bake profile.
With an extensive list of colors exempt from certification, bakers should be able to find the right one for their particular product and process, or even blend several to create beautiful colors.
“So many of the synthetics have been delisted, we no longer have a complete palette of colors on the synthetic side,” Mr. Greaves explained. “Without a natural color, it’s hard to make a really good violet color. It won’t be as good.”
With the extensive palette of colors exempt from certification at their fingertips, bakers don’t have to be limited by these label-friendly ingredients. Instead, they can embrace the opportunities they present to get creative.