Atividade antioxidante de óleos essenciais de folhas de diversas plantas

Abstract

All over the world the socioeconomic differences restrict population access to animal proteins. The cassava leaves are researched to substitute conventional foods, because its proteins, vitamins and minerals content are relatively high, besides its low cost and availability. However, due to the high content of fibers and the presence of antinutritive substances, its direct consumption is limited. The production of cassava leaves protein concentrated (CLPC) allows the use of cassava leaves proteins with reduced content of fibers and of better quality. Although many of those concentrates, yet, present low protein digestibility, they are recommended as functional ingredient in foods due to its high content of proteins, favorable profile of amino acids and of functional properties. This work investigated physical and chemical characteristics of CLPC produced by different forms of precipitation, heat and acid, washed and not washed with organic solvents, aiming at finding a method for improving the protein quality. CLPC precipitated with heat (CLPCH) and with acid (CLPCA) didn’t presented significant differences in the centesimal composition. The levels of protein of CLPC increased 57.72% when compared to cassava leaves flour (CLF), presenting also higher lipid content. The yields of extraction of proteins were also similar for both types of CLPC. The CLPC Fe content was more elevated than that of CLF. The CLPC lavage with ethanol 50% and with ether didn’t improve the protein digestibility; but reduced antinutrient levels. However, the ether lavage cleared CLPC green color. The solvents that improved protein digestibility were acetone and acetone-hexane mixture (1:1.5), that also cleared better the CLPCH green color. The levels of cyanide, saponin and polyphenol of CLPC were reduced when compared to CLF, except for the trypsin inhibitor. Hemagglutinin activity was not observed in any sample. The CLF presented absorption of water and oil higher than CLPC; however both types of CLPC showed similar results. The lowest nitrogen solubility of CLF and of CLPC was observed in pH between 3 and 6. It was verified that CLF possessed a foam formation and stability capacity higher than CLPC. The CLF and CLPC didn't present good emulsion stability. CLF could be indicated for formulation of some types of foods, such as, soups, masses, bakery products, carbonated beverage, and CLPC for soups and sauces formulation.