Principal Investigator Caleb Harper
Project Website https://www.media.mit.edu/projects/openag-flavor-ecology/overview/
Project Start Date October 2017
Project End Date April 2020
NOTE: Optimizing plants for flavor, nutrition, and pharmaceutical content was active from October 2017 to April 2020
The lush, sweet-acid headiness of an excellent peach, a dark and bitter-tinged escarole, a spicy and perfumed basil leaf: flavor is a built-in reward for eating plants that has fueled our drive to domesticate and breed a massive biodiversity of vegetation over the last 10,000 years. OpenAg is going deep into the biochemical machinery, evolution, and ecology of plants to make growing food for flavor a reality.
Plants rely on rich and diverse chemistry for self-defense and stress adaptation. We can induce a plant to synthesize these molecules—essentially, exploiting a natural control loop -- by adding specific stresses to its environment.
These secondary metabolite molecules frequently have extra bioactivities for humans -- as vitamins, antioxidants, stimulants, and in a large number of cases, producing flavors.
Many of these stress-related molecules are also highly flavorful. When we perceive flavor, we are quite literally experiencing biochemical machinery, evolved over millions of years, interacting with stress and ecology.
Flavor, in addition to making the process of eating delicious, is a shortcut for sensing biochemical richness: a highly-flavored plant generally contains more and a greater diversity of molecules, with useful functional roles in our own metabolism, than a bland-tasting plant.
Organisms have two types of biochemical pathways to produce molecules.
Primary or essential metabolism varies very little across most kingdoms of life, includes the mechanisms for creating energy, making new cells, and translating DNA into RNA and proteins.
Secondary or specialized metabolism siphons off the intermediate and product molecules of primary metabolism, and creates new molecules that aren't essential to the life of the cell, but help the organism to specialize and adapt to an evolutionary niche.
When the first land plants evolved from algae, for example, they adapted to new stress from ultraviolet light and dessication by developing molecules that acted as antioxidants and cuticles.
Lemongrass and basil siphon off Acetyl-CoA from the energy-producing Krebs cycle and alter it to produce monoterpene molecules like citral, linalool, and limonene as UV-protecting sunscreen and antifungal agents. These monoterpenes also smell like lemon peel, flowers, and oranges.
Tobacco uses vitamin B3 and Coffee uses ribonucleic acids to produce psychoactive alkaloids, nicotine and caffeine, as insect repellant and to help them compete with other plants.
Cloves borrow the amino acid phenylalanine from their protein-building process and turn it into the phenylpropene molecule eugenol as a deterrent for insects. Eugenol is what makes cloves smell like cloves. In chiles, phenylalanine and fatty acids are combined to make the herbivore deterrent capsaicin—we’ve grown to love its potent spiciness.