RAQUEL DO CARMO SANTOS

ABiodegradable packaging is one of the most recent alternatives that has aroused the interest of Brazilian researchers. Traditional synthetic plastic packaging, although it guarantees the desired protection for different types of products, causes serious problems for the environment as it is not biodegradable. At Unicamp, the subject is being studied by a team from the Process Engineering Laboratory of the Faculty of Food Engineering (FEA), made up of professor Florencia Cecília Menegalli and postgraduate students Delia Rita Tapia Blácido and Eliane Colla. Using amaranth flour (read text on this page), Delia Rita created an edible biofilm. "We studied the feasibility of developing the product, in addition to encouraging the cultivation of amaranth in Brazil", explains Florência.

The research resulted in the master's thesis "Elaboration and characterization of biofilms based on amaranth flour", supervised by Professor Florencia, co-supervised by Professor Paulo Sobral from USP (Pirrassununga) and presented, last March, at the FEA. In addition to this research, the project also gained strength within the Cyted Cooperation Program, which brings together countries such as Portugal and Spain in the development of biofilms of natural origin.

Peruvian, Delia Rita explains that since she was a little girl she saw amaranth being eaten during meals in her country. “We use it there as a cereal for breakfast,” she says. It is a cheap product, with high protein quality and a high concentration of carbohydrates. "Its nutritional value is even higher than that of other cereals." As a result, in addition to developing a product that was not harmful to the environment, the team also created a film that can be ingested by consumers and be good for their health.

The biggest challenge, according to Florência, is to obtain a material with mechanical and barrier properties equivalent to those traditionally used. "Synthetic plastics have the advantage of mechanical resistance, that is, they protect the product very well." In the case of biodegradable materials, explains the professor, the resistance is lower and the solubility is much greater. However, amaranth-based biofilms have excellent barrier properties to moisture and the migration of solutes important for food preservation. It is precisely in this item that Delia Rita is continuing her research as a doctoral student at FEA. She intends to add other bio-polymers to amaranth flour in order to improve mechanical resistance. Eliane Colla should add other lipids in order to further improve the barrier properties.

One of the suggestions for using this edible biofilm is for coverage, applied directly to the surface of food. Florencia cites perishable fruits such as strawberries or similar fruits as an example. "The packaging can even increase the shelf life of the product, as with the barrier there is a loss of moisture and the possibility of incorporating anti-microbial agents into the packaging itself."

Transformation - To reach biofilm, amaranth goes through several stages of transformation. First, the grains are macerated in an alkaline solution, after which they are ground and sieved until the fiber is extracted. After filtering, the solution is neutralized and centrifuged to obtain amaranth flour. Flour is basically made up of starch, proteins and lipids. From there, to formulate the films, an amaranth suspension is prepared at a given concentration and subjected to a thermal process for gelatinization. In general, the process is carried out in 45 minutes. After which the pH is adjusted and the plasticizer is added, which will increase the flexibility of the film. At this point the mixtures are placed on supports and dried. Drying alone requires approximately eight hours. In this thesis, using statistical planning techniques, the ideal process and drying temperature was found and the formulation in which the greatest mechanical resistance and lowest solubility were obtained.

Another aspect that scientists want to understand is what influence this body composition has on the sexual dimorphism of the population analyzed. It is known that women have more fat mass than men. However, among poor individuals the differences decrease, since, due to nutritional deficiency, both men and women have similar body characteristics. "Reducing fat mass brings one closer to the other. We want to see how this is going," she says.