Indigenous plants: Safer alternative to artificial food coloring products

MANILA, Philippines — Color plays an important role in our food preference. It can predetermine how we perceive the taste and flavor of what we’re about to eat.

In fresh foods, we rely on the color to determine their level of ripeness or freshness. For processed food, it becomes a whole different topic. When food undergoes processing, it loses its naturally vibrant color, thus the need for artificial color additives or food coloring.

Artificial coloring makes any food product more delectable and mouth-watering. Unfortunately, some of them are actually harmful to the body

To address this, researchers from the University of the Philippines Los Baños (UPLB) led by Lourdes Cardenas of the Institute of Biological Sciences, conducted a study in the hope of providing the public a healthy and safe alternative to artificial food coloring using indigenous plants.

Funded by the Bureau of Agricultural Research, the study, “Biotechnology in the Utilization of Natural Colors from Indigenous Plants,” aims to identify indigenous plants with health benefitting natural colors and develop technologies using them.

The study screened over 20 indigenous plant species among them included alugbati, lipote, duhat, gumamela, roselle, butterfly pea, pandan, turmeric, barberry, kamantigi, begonia, mayana leaf, bougainvilla,talinum, oxalis, impatients, portulaca, nasturtium, and bell pepper.

These indigenous plants were screened using the following criteria:  toxicity, tinctorial strength but with minimal or without imparting any flavor or aroma, availability of the raw materials and ease of handling, mutagenicity  and stability of the pigment under different pH, temperature, and light regimen.

Also considered in choosing the plant pigment as food colorant are solubility in water and demand of a particular color in the market.

As potential food colorants, the researchers included plant species with Anthocyanins and Betalains, these are plant pigments that are water soluble. 

Carotenoids were not included in the study as these pigments are not water soluble and are sensitive to light.

Meanwhile, the researchers included Curcuminoids (not water soluble), which could be found in turmeric, because it was found to be the best alternative natural colorant to Tartrazine.

To get the results, the colorants were tested under different types of food preparation: fresh, steamed, boiled, and baked. They prepared salad using the begonia, and ice cones or scramble with a whole extract fromlipote, turmeric, and butterfly pea directly poured on top of the shaved ice.

Results of the study showed that among the plant species tested, the best sources of red colorant are: alugbati, lipote and red 4 o’clock .

Meanwhile, the best source for yellow pigment is turmeric, for blue pigment it is butterfly pea and for green pigment it is pandan.

Duhat, red gumamela and roselle  were dropped from the list due to factors involving toxicity, stability of pigment, availability of raw materials, and difficulty in extraction of pigment, among others.

The researchers noted that not all pigments from the plant species could be processed into colorants due to low tinctorial strength, and fragility, among others.– Rita dela Cruz