Otimização do processo de produção de um extracto fungicida de Lupinus albus

Mestrado em Engenharia Alimentar - Instituto Superior de AgronomiaThe Lupinus genus had its origin in the Mediterranean basin and in North Africa, with existing records of its cultivation in Egypt about 4000 years ago. The four main species of the Lupinus genus in the world are L. albus, L. angustifolius, L. luteus and L. mutabilis, being Australia the world biggest producer. The main reasons for its cultivation are human consumption, green manure, animal feed and its use as a protein supplement. The discovery of a polypeptide extracted from cells of the germinated cotyledons with antifungal properties and biostimulant ability created an innovative application for lupine: the production of a biofungicide. Damage of the cotyledonary tissue led to a decrease in protein content available for extraction. Germination of a sweet variety in the presence of bitter seeds suggested that there was an increase in the amount of protein available for extraction from sweet seeds. It was possible to obtain a concentrated extract by clarifying the extract using a thermal fractionation method. The concentrated extract was combined successfully with a number of surfactant agents, from which the most appropriate were chosen according to wetting and spreadability properties and to the concept of a non-synthetic biofungicide. The formulated extract showed a strong buffering capacity and a high resistance to stress factors such as temperature and agitation during an eight week period. Evaporation proved to be an adequate method of concentration at pilot scale as an alternative to laboratory-scale freeze-drying. The production of a concentrated extract with 20% (w/w) protein was possible through the extract concentration with tree single step evaporations. The first two were separated by a thermal fractionation. Between the second and the third evaporation there was a resting period at cold temperature, centrifugation and formulation process of the product. It has been shown the existence of more suitable varieties of Lupinus for large scale production of concentrated extract, being the most appropriate of the three studied the Amiga variety