- Jun 14, 2017 -
Natural ingredients are the gold standard in the food and beverage industry today, and food colorants are no exception. The wave of consumer demand for both cleaner labels and the perception of healthier foods is leading¡ªperhaps, at times, forcing¡ªchanges in the types of ingredients used in processed foods.As these challenges yield to technical solutions, there¡¯s a steady increase in the use of natural colorants in applications that traditionally relied on synthetics.
A number of naturally sourced colorants are available in other global markets but not in the US. Most food product developers and manufacturers, as well as marketers, food scientists, and regulatory specialists, are well aware of this fact. Some of these colorants are approved for use in the EU; some only in markets such as Asia.
Natural food colorants are extracted from the gardenia plant (Gardenia jasminoides). Its major coloring compound is crocin, but iridoid and flavonoid coloring compounds also are produced in the plant. Interestingly, crocin (along with crocetin) is a primary coloring compound in saffron, which is permitted in the US. Gardenia yellow is approved for use throughout Asia, and it is commonly used in many applications. For instance, in China higher quality instant noodles are frequently colored with gardenia yellow.
Safflower yellow is a bright yellow-to-reddish colorant permitted for use in food in Asia and Europe, but not in the US. The safflower plant itself, Carthamus tinctorius, is grown mainly for its seeds, used to produce an edible oil. The fruit of the plant is extracted to yield three primary colorants, Carthamin, Safflor Yellow A, and Safflor Yellow B. Safflower Yellow is a suitable replacement for FD&C Yellow #5.
Turmeric has become one of the preferred natural yellow colorings of late and is becoming widely used in the US as a replacement for Yellow No. 5. But turmeric oleoresin is notoriously unstable in direct light. For this reason, its applications are severely restricted. Moreover, the coloring agent in turmeric oleoresin (curcumin) is not naturally water-soluble, and is even barely soluble in oil. This means it must be formulated with an emulsifier for applications in water-based systems.
Red yeast rice is a colorant obtained from a fermentation of rice by the Monascus purpureus mold. It is permitted for coloring food throughout Asia but not in Europe or the US. (It is, however, an approved nutritional supplement in the US.)
The coloring agents structurally are similar red and yellow compounds. Monascus coloring preparations can be used to impart a red color suitable as a replacement for FD&C Red #40 in some applications. It demonstrates good stability to heat under neutral pH conditions but will fade upon prolonged exposure to light.
True Blue and Green
Chlorophyll is found abundantly throughout nature as the green color characteristic of photosynthetic plants. In its natural state, chlorophyll has a porphyrin ring structure that is associated with a magnesium ion (Mg) bound in the central receptor location. In this state, chlorophyll extracts produce a bright green color in many food and beverage applications, although with limited stability.
Since stable, natural green colorants are rare, chlorophyllin potentially could fill a much larger role in the coloration of prepared foods. Chlorophyll colorants are more broadly permitted for use in the EU, where they are produced by extraction of permitted plant materials, mainly alfalfa.
Spirulina extract as a colorant is relatively new to the US market. It is derived from the edible algae from which it gets its name, and, as a whole cell preparation, it has been used as a food and as a dietary supplement for decades. It is derived from the blue-green, edible algae from which it gets its name. (There are two main species, Arthrospira platensis and Arthrospira maxima.) As a whole-cell preparation, spirulina has been used as a food and a dietary supplement for decades.
Spirulina is one of the few natural blue colorants that has attained approval for use in foods and beverages in the US. Extracts that isolate the blue phycocyanin compounds may be used by themselves to impart blue colors, or in combination with naturally derived yellow colorants to achieve shades of green. Examples include turmeric oleoresin, beta-carotene, safflower extract, and yellow gardenia. Spirulina is reported to be broadly useful and relatively pH- and heat-stable in applications where water activity is relatively low, such as confectionery.