Source: Science Meets Food

By Emanueli Backes

Who doesn’t like colorful, tasty food? I do and I bet you do too! I would also venture to say that an attractive color is a major deciding factor for whether you choose one product instead of another on the supermarket shelves. Despite its appetizing look, colorful food is often made with synthetic dyes, some of which might lead to doubts about its safety1-3. However, while more studies are required to better understand this suspicion, you should not worry or stop eating delicious foods. With the increase of naturally derived ingredients on food labels, scientists have been searching for natural pigments that not only satisfy a “natural” label claim but may also help reduce food waste and make colorful food even healthier. Yes, we may be able to kill two birds with one stone!

Fortunately for the lovers of colorful food and thanks to the hard work of researchers, many natural sources (such as flowers, vegetables, and fruits) have been used to obtain natural colorful extracts. Compared to these expensive natural sources, a cheaper solution has gained more attention in recent years. Obtaining natural colorants from plant waste products is also possible. No, you are not misunderstanding. Imagine using waste as an intelligent, eco-friendly, and safe alternative for natural pigments. Amazing, right?

Almost 1.3 billion tons of food waste are produced per year. That’s a lot of residue. 50% of this waste is from fruits, vegetables, and root crops; all of which are rich sources of different colorant compounds4. The largest fraction of this waste derives from the food industry, who could highly benefit from the reuse of their very own waste. This would limit excess money spent on waste treatment and disposal, by creating a rentable utility for this residues. The production of natural pigments from agro-waste appears to be a good solution for consumer health, business, and the environment.

Nature can provide all kinds of color. While carotenoids are responsible for the yellow and orange colors of carrots, oranges, and mangoes, chlorophyll is a pervasive green pigment present in plant leaves. Additionally, anthocyanins represent the largest group of water-soluble pigments in plants, who’s color varies from red to purple, or blue depending on the pH level of the media. These compounds are commonly found in grape and wine industry by-products. All of these natural pigments have a huge potential as food colorants5,6.