What are the properties of carrots? Let’s see: rich in beta-carotene, carrots give splendor to the skin and preserve eyesight. Because of carrots potassium and phosphorus content, it is an excellent invigorating for tired minds and restorative nerves. But it is now possible to add one more: its waste can be transformed into biofuel.
Researchers from the National Council of Scientific and Technical Research (CONICET) and the National University of the Coast (UNL), in Argentina, have already achieved it. The project started in 2013 to give an exit to the surplus of carrots in the town of Santa Fe. Of every 10,000 kilos produced in the region, 4,000 ended up as waste. This accumulation of garbage generated problems, bad smells, soil degradation and rodent proliferation.
That year, the Val Mar company dedicated to the washing and packing of carrots in the town of Santa Rosa de Calchines, and contacted the researchers in order to find a solution. The idea that emerged was to create a plant that allowed the recycling of vegetable waste in biofuels and dietary supplements.
The first step that scientists took was to study the composition of the carrot. “This vegetable is composed of eighty percent water, but if we continue in decreasing order, sugars appear – almost entirely fermentable and possible to transform into alcohol – then fibers and carotenes,” says chemist Juan Carlos Yori, of the Research Institute in Catalysis and Petrochemicals (INCAPE). With that information, in 2014 they devised a plant to produce bioethanol, fibers and natural dyes from waste. First they built it on a laboratory scale and in September 2018, it could be inaugurated as a pilot plant with the capacity to process two tons of surplus per day.
According to the authors of this project, the sugars present in the carrot have the characteristic of being entirely fermentable, so they can be transformed into second generation bioethanol, useful for the fuel, beverage, pharmacopoeia and perfume industry, among other applications. The biofuel produced in the pilot plant is used as an extraction solvent to obtain other bioproducts, dietary fibers and carotenes.
These bioproducts require a stage of refinement and adaptation of their properties to be able to use them as additives for the preparation of functional foods or dietary supplements. “At this stage we were able to take the by-products to a phase of use in food and in the form of dietary supplements. One of the results was a carotene (natural dye) that we had to emulsify to present it as the dyes that a baker buys or the pasta factory. We also tested the incorporation of fiber in the manufacture of sausages, hamburgers and cold cuts. And when it comes to cheese and yogurt, we did it in collaboration with INLAIN (CONICET-UNL),” explains Yori.
Currently the pilot plant already generates natural dye, capsules and tablets of dietary fiber for personal consumption and packaged fiber to incorporate into food production. Regarding profitability, although the initial objective of the pilot plant was to recover the costs of what the producer loses with the surplus of the carrot, the results went further. The cost of seeds, sowing, tillage, irrigation, pesticides and harvest is one thousand dollars per hectare. With the surpluses, of every three hectares planted with carrots, the producer loses one. With its passage through the industrial plant it is possible that with every one hundred tons of carrot 5,000 liters of alcohol can be produced (with a price of one dollar per liter), 20 kilos of carotene (between 750 and 1,000 dollars per kilo) and 3,000 kilos of fiber (at $ 15 a kilo),