Potential use of Macaúba for biokerosene production and recovery of degraded pastures in Brazil

9 de March de 2015

Produtos oriundos da macaúbaMacaúba can produce various products of industrial interest, which optimizes the processing and generates more income for growers.

A plant which is commonly found throughout Brazil can become the newest source of clean energy for world aviation. Major international airlines are looking for alternatives to the kerosene that moves airplane turbines, and macaúba may be the solution. The difficulties that could hinder the transformation of a rustic plant into a great business for farmers have been overcome. Studies conducted at the Universidade Federal de Viçosa (UFV) have focused on the production chain of macaúba, which has the potential to become the new green gold of Brazil. The state of Minas Gerais is able to lead such business by taking advantage of degraded pastures and using them for agroforestry activities.

The UFV is participating in the Minas Gerais Biokerosene platform and in meetings with airline companies committed to reduce by half the emission of greenhouse gases until 2020. Technologies aimed at using lighter materials for aircraft construction and reducing the costs with fuel are limited; thus, companies are searching for renewable fuels that do not compete with foods such as soybean and sugar cane. “Among all other options, macaúba seems to be the most successful alternative to biokerosene production, not only for its oil quality, but also because it can be fully used for commercial purposes” says Professor Sérgio Motoike, the coordinator of UFV macaúba research team.

Macaúba is an oil palm that can be found in different areas in Brazil. Its most productive populations are concentrated in Minas Gerais. The plant is rustic, easily adaptable and well known by farmers. Its fruits can be eaten by livestock or people interested in its almond, which has a sweet smell and tastes like coconut. A few decades ago, Paraguay, Brazil and other countries used to make soap from macaúba oil. However, as explained by Professor Motoike, the commercial cultivation of the plant was hindered by the low rate of seed germination and the lack of agronomic knowledge to improve productivity and harvesting and processing techniques, but these problems have been overcome. The researchers of the UFV Department of Plant Science have been studying the entire macaúba production process for over ten years and have already mastered all the necessary knowledge to turn macaúba into a viable commercial alternative for Brazil.

professores macaúbaUFV Professors Sergio Motoike, José Antônio Grossi and other researchers from the Department of Plant Science have already found technological solutions for the entire macaúba production system.

From seed to harvest

Nowadays, the UFV holds a large macaúba germplasm bank, which may be the largest in the world, with seeds and seedlings of different varieties from Brazil and other Latin American countries. Professor Motoike states that rustic seeds are used for macaúba genetic breeding, so as to create more productive varieties, resistant to pests and adaptable to different climates and environments.

Turning a wild plant as macaúba into a domesticated crop plant requires a coordinated work of various areas of agronomy. Seed germination difficulties have been solved long ago and the UFV holds the patent of an efficient technique for improved germination, which was developed by the team led by Professor Motoike,  and has been used by seedling production companies.

After ensuring quality seedlings, it was necessary to improve the cultural practices required by the crop. Professor Leonardo Pimentel has been responsible for this task and has already developed research to define the best planting practices, spacing between plants and rows, nutritional requirements for fertilization and to identify the main diseases that can affect a commercial crop. A macaúba tree takes four years to bear fruits. The plant is perennial and, when properly fertilized, bears fruits for many years. A commercial plantation can cultivate more than 400 plants per hectare. With the use of the new technologies available, a hectare is expected to produce 25000 Kg of macaúba per harvest per hectare, which generates 5000 Kg of oil per year.

Research has been conducted with the financial support of the Petrobras company, which intends to use the plant for biodiesel production. Some European companies are also interested in macaúba. The advances achieved by the UFV research team are available to students from various countries at the UFV Macaúba Post-harvest Laboratory. However, Professor Sérgio Motoike has been making efforts for this plant to be exploited in Brazil and to become a source of income, especially for small farmers. He states that “Macaúba is 100% usable and has the potential to be an environmentally sustainable culture. We are sure that it is a very interesting investment”.

 A versatile product

The industrial sector is interested in macaúba oil for the production of biodiesel and biokerosene, but growers can optimize the culture and use it for other purposes as well. Macaúba produces two oils with different qualities. The nut oil is obtained from the core of the fruit and is similar to coconut oil or palm oil. It is fragrant, palatable and can be used both in food and cosmetic industries. It is also possible to use the endocarp, which is the part that surrounds the nut, in order to protect the seed and separate the two sources of oils. The endocarp is dark and similar to wood, stiff and difficult to brake. Therefore, it has been successfully used as activated charcoal, with high calorific value and smoke free from toxic emissions. It can also be used for the production of filters and dirt retention.

 On the other hand, oil for biofuel is extracted from the soft part, the mesocarp, which needs to be processed properly for better oil recovery. What remains of the extraction can be ground into flour for both human consumption and animal feed, since it is palatable and free from toxicity. The UFV team has already calculated the yield and revenue of each macaúba byproduct to promote the cultivation of the plant. The results are very interesting for commercial purposes.

Why haven’t macaúba financial advantages attracted farmers before?  Professor Sergio Motoike points out three reasons for that. The first is the lack of interest from a large industry and lack of a long-term practical application, such as sustainable aviation bio-kerosene. Second, there were no solid research works on the entire production chain able to clarify the doubts of farmers. And lastly, there was a problem related to macaúba cultivation that has also been solved by the UFV team. In extractivist traditional practices, still performed nowadays, macaúba coconuts fall to the ground and are eaten by cattle. Growers expect them to fall in larger quantities so they can sell them to the soap industry. Since they fall on different days and are in contact with soil moisture, the coconuts rot and the oil deteriorates and darkens, thus loosing its commercial value. Biofuel industry would also reject deteriorated oil.

“Macaúba advantages can be utilized only when harvesting logistics and a commercial extraction process are employed” says Professor José Antonio Grossi, who is in charge of investigating post-harvest and quality of macaúba oils. He explains that the plant takes 12-14 months to fully form its fruits. Breeders have already extended the time that the fruit adheres to the plant, thus avoiding the early fall and rotting. Other studies have improved fruit storage technology and retarded oil rancidity. “Macaúba produces a hormone that causes ripening to continue after harvest and now we have knowledge to interfere in this process,” says Professor Grossi. “The good news is that the technique developed by the UFV team, besides retarding decay, also increased by 20% the content of macaúba oil. We have to give more time for the industry to process this oil. The season usually occurs from November to February, but, with the help of the germplasm bank and breeding procedures, we will have ripe fruits in other periods of the year as well, “says the professor.

An alternative to degraded pasture areas

The environmental sustainability of commercial plantations is another factor that encourages researchers and entrepreneurs, since macaúba adapts very well to intercropped plantations, especially in pasture areas. “Today, 160 million hectares of Brazilian land are used for grazing. In Minas Gerais alone, 40% of this area is degraded due to poor land use. The emission of greenhouse gases caused by bovine eructation is another serious environmental problem. We need to turn this into an opportunity, “says Professor Motoike.

SONY DSCThe UFV researchers propose the macaúba-pasture intercrop, so as to recover degraded areas throughout the country and prevent deforestation in the Amazon.

The team of the UFV department of Plant Science aims to encourage the consortium of plants and animals in the same area. First, it is necessary to recover soils degraded by pastures with the use of correct fertilization and plant palm trees. In three years, the plants grow enough to not be eaten by cattle. “Palm tree architecture allows this arrangement,” explains Professor Motoike. The leaves do not shade the understorey and let through an amount of light optimal to the growth of pastures such as Brachiaria. Furthermore, the plants provide shade, thus improving the ambience for cattle. “It’s a two-story agriculture,” says Professor Motoike. In this case, the consortium should be implemented gradually, starting with one third of the area to give time for plants to grow and soils to recover. Plants with denser canopy, such as oil palm, are inadequate for the consortium.

“It is a closed system,” says the professor. “We do not intend to use areas already used for food production, rather degraded areas, which we aim to recover. If soybean, for example, occupies grazing areas, it pushes cattle to the Amazon Forest. In macaúba system, a healthy coexistence is possible in an area that had been degraded. A healthier environment for the consortium with livestock should be created”. Research works have also been conducted on macaúba-bean intercrop.

The team of researchers from the Universidade Federal de Viçosa have already published dozens of papers on macaúba cultivation and post-harvest that are available to growers and entrepreneurs interested in learning more about the benefits of the plant.

( Léa Medeiros )