Research conducted at FEA obtains extract containing fiber that acts as a prebiotic
A master's degree research carried out at Unicamp's Faculty of Food Engineering (FEA) managed to obtain an extract from roasted açaí seeds rich in inulin, a soluble fiber that acts as a prebiotic, facilitating the absorption of minerals in the intestine and preventing the retention of belly, in addition to having an important role in reducing cholesterol and controlling blood sugar levels. Conducted by food engineer Renata Magalhães at the university's Extraction, Applied Thermodynamics and Equilibrium Laboratory (Extrae), the study found that the conventional extraction method – similar to that used to obtain coffee – proved to be effective in producing a “ açaí coffee”, which can be consumed as an easy-to-prepare functional drink.
“We seek to extract this 'açaí coffee' as is done with regular coffee, just by varying the main process parameters, namely: temperature and solid/solvent ratio. So, my work involved evaluating five different levels of process parameters”, explains the scientist, who verified, in her analyses, that the drink contains 16% inulin, an index considered high for an extract. The expectation is that the results obtained can be useful in the development of production processes on an industrial scale, helping to generate a product with greater added value from a raw material that is generally discarded and causes various environmental impacts.
Currently, few companies in Brazil are dedicated to creating products from açaí seeds, which are often deposited in inappropriate places such as landfills, rivers and around factories. As only 15% of this fruit is made up of the endocarp, its edible part – the remaining 85% corresponds to the seed and peel – tons of waste are generated by the açaí agro-industrial chain. To give you an idea, according to data from the Brazilian Institute of Geography and Statistics (IBGE), in 2019 alone, more than 220 thousand tons of products were produced from açaí in Brazil.
As it is a solid material with a large amount of cellulose and lignin, the açaí seed is a by-product that can be transformed using biotechnological solutions. “The organic solid waste from açaí seeds can be used in composting processes or be part of the global energy matrix, which is basically made up of non-renewable sources. Thus, the use of this resource has an economic, social well-being and, above all, health benefit bias”, comments professor Klícia Sampaio, who supervised Magalhães' research.
In addition to obtaining inulin, the dissertation also analyzed the characteristics of phenolic compounds present in “açaí coffee” – a group of antioxidants produced by plants and which helps defend the body against various types of cancer – and the physicochemical parameters of the roasted seed powder, such as particle diameter and protein, carbohydrate and crude fiber content. The measurement aims to help extract the maximum benefits from that material, both to produce a richer compound and to improve the use of the resource.
As Professor Eduardo Batista, who co-supervised the dissertation, explains, even with the creation of products with greater added value, the use of roasted seeds continues to generate waste, as is the case with the grounds left after straining the coffee. “It is important for us to understand what is in that material because coffee powder is a serious environmental problem. If you use a material for less than two minutes and generate waste, this is considered an environmental problem. And traditional coffee generates a lot of waste. We know that, with açaí coffee, we are not going to eliminate the production of waste, so we are trying to extract other components of interest so that we can find other destinations for that material”, he comments.
The study
The idea of obtaining inulin from açaí extract arose in 2020, when the company Raízes do Açaí from Pará, which produces coffee from this fruit, contacted Sampaio, making the product available for study. A nutritionist had gone viral on the internet with a video in which she claimed that drinking that coffee would help diabetics control their blood sugar, which caused the company's stocks – a small one – to run out. Without knowing what could be behind this eventual effect of the drink, Raízes do Açaí proposed a partnership to Unicamp.
Magalhães, imbued with the mission of clarifying this situation, initially carried out a bibliographical research, finding articles in which the presence of inulin in the material was indicated. With this data in hand, the researcher directed her efforts to analyzing this substance. To do so, the student used an ion chromatograph – equipment that identifies and quantifies chemical compounds present in liquid materials –, which allowed analyzes to be carried out in a way that was less harmful to the environment. In general, traditional chromatography uses toxic solvents that are very dangerous for the analyst. However, with the ion chromatograph, it was possible to carry out the study using only water, generating less waste, at a low cost and in a safer way for scientists.
According to laboratory technician Patrícia Tonon, the chemist responsible for the ion chromatograph at Extrae and for training the student Magalhães, this is extremely sensitive equipment, which presented results as good as those of more conventional techniques used in analyzes of this type. Its sensitivity is so high that it was necessary to dilute the açaí seed extract in 20 parts of water to adapt the detector's response to the analytical curve. “And it was also a very rich extract, even diluted. In the end, the method proved to be very robust, precise, reproducible and gave an excellent response. For a master's degree, which lasts for a short period of two years, it was a big job to develop the methodology for ion chromatography and evaluate the extraction process of bioactive compounds”, says the scientist.