Caracterização físico-químico e funcional das proteínas de amêndoas do pinhão manso

Abstract

Jatropha (Jatropha curcas L.), oleaginous plant from Euphorbiaceae Family, is a source of protein, little explored in this way, because the presence of antinutritional and toxic factors make the culture unattractive for this purpose. The aim of this study was to characterize the protein fraction of the jatropha almond on the nutritional aspects, functional and physicochemical properties, thus enabling to establish their potential use as functional ingredients in food manufactured products. Almond showed high lipid content (41.98%) and protein (24.06%) and after defatted, presented 1.02% and 51.66% respectively. To obtain the isolated protein, almonds defatted protein were extracted at pH 7.2 and 10.0 and isoelectric precipitation at pH 4.0, 4.5, 5.0 and 5.5, being observed more pronounced yield at pH 10.0, with precipitation at pH 4.0. In these same pH index were obtained two isolated protein (IP10.0 e IP7.2), which were subjected to analysis of functional properties, such as solubility, absorption capacity for water and oil and emulsifying capacity. The isolates showed higher solubilities at pH 10, and minimum around the isoelectric point. The two isolates exhibited high absorption capacities of water and oil, and good emulsifying capacity for application in bakery products, and meat sauces. The thermal properties of the protein isolates and fractions were analyzed by differential scanning calorimetry (DSC), and it was observed that the IP10.0 showed better thermal stability, as well as globulins, albumins compared. The results of this study indicate that the isolated protein obtained from jatropha almonds can not be inserted in the feed composition due to the presence of phorbol esters. Therefore, new experiments must involve processes aimed at removal of toxic and antinutritional factors.