Obtenção da farinha da semente de jaca germinada.

Abstract

Jackfruits (Artocarpus heterophyllus Lam.) are rich in carbohydrates, calcium, phosphorus, iron and B vitamin. However, a large amount of waste/residue is generated during its processing, such as the seeds. As a means of utilization, residual jackfruit seeds can be germinated because the germination process confers biochemical modifications, thus improving its nutritional quality and they can then be dehydrated and transformed into flour that can be used in human food. In view of this, this study aimed at producing flour from germinated jackfruit seeds. The seeds were placed in trays with vermiculite substrate and kept at room temperature and relative humidity, and they were irrigated daily with distilled water until they reached the desired radicle size (2.5 cm). The germinated seeds were submitted to drying process using a convective drier at temperatures of 55, 65 and 75 °C and drying air velocities of 1.0 and 1.3 m/s. Diffusion Approximation, Two Terms, Midilli, Page and Thompson mathematical models were adjusted to the kinetic drying curves of the seeds. After the drying process, dehydrated jackfruit seeds were ground in a knife mill to obtain the flour, which was then characterized in terms of chemical, physical, physico-chemical and technological properties. Moisture adsorption isotherms of the flour was determined using the Aqualab hygrometer at a temperature of 25 °C; Oswin, Peleg and GAB models were adjusted to the isotherms. The flour from germinated jackfruit seeds that obtained the best results of water activity and solubility was evaluated for tannins, phenolic compounds, mineral profile and cytotoxicity. Data were submitted to analysis of variance and mean comparisons were carried out by Tukey test at 5% probability using the Assistat program, version 7.7 beta. It was possible to observe that germination increased the moisture content, proteins, fibers and total sugars of the seeds and decreased the content of lipids, reducing sugars, tannins and phenolic compounds. The Two Terms model was the best fit for the drying kinetics experimental data. With the thermal process, moisture content of the flour decreased, concentrating proteins and reducing sugars, in addition to presenting luminosity tending to white. With regard to technological properties, the flour from germinated jackfruit seeds showed good results for solubility, moisture and oil absorption capacity and emulsifying properties; however, gelation capacity was 22%, indicating a limitation of its use in products that require this property. Moisture adsorption isotherms of germinated jackfruit seed flour was classified as Type II, and the GAB model was considered the best fit for the experimental curves. Tannins and phenolic compounds levels in the selected flour were observed in relation to germinated jackfruit seeds before drying. The flour from germinated jackfruit seeds was considered non-toxic, presenting LD50 values above 1000 μg/mL.