Image Courtesy: SIU Carbondale Communications
Scientists have developed a system that can transform discarded plastic and agricultural waste into food ingredients, then use them to produce a cookie. The experimental technology, developed by researchers at Southern Illinois University Carbondale, could eventually provide a way to produce food in places where conventional supplies are difficult to access.
The cookies, called µBites, were developed as part of NASA’s Deep Space Food Challenge and recently presented at an American Chemical Society symposium. The team says the system could eventually be used in disaster zones, submarines, remote environments, and potentially on the Moon or Mars.
The process begins with polyethylene terephthalate, or PET, the plastic commonly used in bottles and food containers. Researchers combine the plastic with agricultural waste such as corn stalks and leaves, then subject the material to oxidative hydrothermal dissolution, using water, oxygen, high temperatures, and high pressure to break it down into its basic carbon components.
That resulting liquid feedstock is given to specially cultured yeast, which converts the material into what researchers describe as nutritious food slurries. The team has engineered different yeast strains to produce useful food components, including proteins, lipids, vitamins, aromas, colors, and flavorings.
One strain produces vanillin, the compound responsible for vanilla’s characteristic flavor and aroma. Another produces beta-carotene, an orange pigment that the body can convert into vitamin A.
The ingredients are combined into dough and shaped using a 3D food printer before being cooked in a microwave. The researchers say the finished cookies have passed laboratory analyses designed to check for toxic chemicals, heavy metals, allergens, and pathogens.
However, nobody has been allowed to eat the cookies yet. The team is conducting simulated digestion studies and other safety assessments before moving toward human testing. Sensory evaluations so far indicate that the cookies have a pleasant smell and texture.
The current system takes one to two days and converts more than half of the carbon in its waste feedstocks into food products. Researchers hope future versions will recycle more of the remaining carbon, although some material would still be released as waste gas or remain unconverted.
The technology currently involves 33 steps, and adapting it for microgravity presents another major challenge. The researchers also stress that cookies are only a proof of concept. The resulting ingredients could potentially be used in meat and dairy alternatives, as well as animal feed.
For now, the idea of eating a cookie made from a discarded plastic bottle remains firmly in the experimental stage.
