Almost every morning, when I sit by the window and start my day, I envelop myself in the initial rays of the sun. For me, it brings out an extraordinary awakening when colors become visible again. Even dark brown coffee brightens with sun rays and propels me to write this deep dive exploring the natural relation between light and color. In this text, I want to nudge myself and the readers to reflect on colors and how they connect to our being. Taking a cue from the manifesto of Alice Waters We are what we eat, I aim to provide reflections from my work, emerging food-tech innovations in edible pigmentation.
In our complex food system, colors intertwine within science, design, and culture. A lot of what we eat is decided by its color.
It also influences the sensory perception of food and, hence, is very closely monitored by big players in the food industry. While nature has already engineered colors, our current task has become to re-engineer them somehow to produce food more efficiently. Through my work, I report on new technologies emerging in the startup ecosystem. Spoiler: sunlight (aka dhoop) plays a critical role in their success journeys.
Colors are something we interact with in every moment of our existence but rarely do we consider the reasons. We see colors due to light. For instance, cucumber is green because it reflects the green wave of light. The science behind the existence of colors in food is relatively straightforward. In food, pigments consist of unique light-sensitive molecules that add color. Consider the vibrant blues (phycocyanin) in spirulina or the red-yellow hues (betalain) in beetroot. These belong to four families of pigments in food, namely chlorophyll, carotenoids, flavonoids, and betalains. Pigments in food often change their structure with time. If you wonder why broccoli or kale turns yellow in your fridge, it's because green chlorophyll breaks down and reveals hidden yellow carotenoids. At the outset, however, the color change observed in food is primarily a result of chemical modifications induced by oxygen, i.e., oxidation. This process accelerates in the presence of light.
Not just food, almost every material (including human skin) is subject to change in color as a result of complex chemical reactions, broadly studied in a field called photochemistry.
Food specialists find a particular value through photochemistry to find the exact combination of effects required to achieve longer freshness and high food quality.
Pigments can come from many sources, but the natural ones are tricky to sustain as they oxidize quickly. Their instability depends on the acidity of their environment as well as their exposure to heat. The more stable pigment found in beetroot is helpful for the color of meat substitutes, gelatin, desserts, and dairy products. The root juice is added to intensify the color of tomato products like tomato sauce, puree, and ketchup. However, natural pigments are insufficient to meet the market cost and quality. Imagine growing turmeric to extract 2-5% yellow color (Curcuma), which still needs to be masked with UV-protective packaging to avoid fading in sunlight. That's far too little for an ever-accelerating neoliberal market.
Thus, our reliance on artificial pigments extracted through synthetic (fossil) chemistry routes. These come with the benefit of being cheaper and stable; hence, the curcuma gets replaced with mentail and sunset yellows. With time, we have realized that these are unhealthy and considered harmful by food safety agencies. This does not mean that natural colors provide any more nutritional value than their artificial counterparts. I prefer natural colorants any given day, but studies show that they possess inherent problems connected with their production and properties such as their inconsistency in quality, seasonality, land-use competition with food, complex end-use application, and a limited color gamut.
Further, replacing artificial colors with natural ones is also not agriculturally sustainable, considering their high carbon, land, and water footprint.
Long ago, biological organisms decoded biochemistry to produce them. Now, we are seeing an emergence of alternative technologies using fermentation to do the same in industrial settings. Some like to call it precision fermentation. The quest to diversify the pigment sources is only getting more interesting now. We see a lot of utilization of algae, cyanobacteria, and fungi strains in addition to new plants and vegetables. Large color houses like Givaudan, Oterra, and DSM-Firmenich are spearheading this movement.
Replacing color sources is not quite easy – especially in food applications. Colors come with their unique taste and flavor, and hence, a change in the recipe is required to accommodate newcomers. During a call with an expert, I learned that the easiest way to assess any food colorant is to start with candy. Simply put, confectionary is the low-hanging fruit for novel color producers. To step up to level two, try baked goods and even beverages. More interestingly, modern buyers are looking for plant-based and clean-label products. Imagine the uproar in a country like India for adding red crimson (carmine) obtained from cochineal insects when other countries have used it as their primary red for ages.
Unlike Holi, there is a lot of color-play in action almost every day in the research labs of big food players. Since this involves immense sensory interplay, I want to see a future where colorants can replace sugar and still maintain sweetness in food. While selecting the color of choice for food application, one of the most critical aspects of the colorant tests is to perform well in natural light. If the samples do not perform well in the sun, the colors are deemed unqualified for the application. Most food products kept in plastic packaging have a sticker saying "avoid direct sunlight" to prevent photochemical reactions.
After giving it a second thought, the relationship between sunlight and food seems quite paradoxical to me. While light is essential for producing all the food we need, the same process takes away colors, nutrients, and the existence of "food" in food. The twofold function of the sun to produce and take away the color from food leaves me wondering about its multifaceted nature; the idea of literally adding colors to give it life and slowly taking it away.