Effect of Alkaline Agent and pH on the Composition of Freeze-Dried Proteins Extracted from Castor Bean (Ricinus communis L.) Cake

Author(s)

Makishi, Gisele L. A. ; Lacerda, Roseli S. ; Mamani, Hulda N. C. ; Costa, Patricia A. ; Bittante, Ana Monica Q. B. ; Gomide, Catarina A. ; Sobral, Paulo J. A. ; Ranzi, E ; KohseHoinghaus, K

• Document type: Journal article
• Source: PRES 2011: 14TH INTERNATIONAL CONFERENCE ON PROCESS INTEGRATION, MODELLING AND OPTIMISATION FOR ENERGY SAVING AND POLLUTION REDUCTION, PTS 1 AND 2; v. 37, p. 3-pg., 2014-01-01.

Abstract

Castor-bean cake, a by-product of biodiesel industry, has been used as fertilizer and as parasitic control in soil. However, its protein could be extracted and used to produce biodegradable materials, enhancing the value of this raw material. The most common process for protein extraction uses alkaline solubilisation, which is also the main treatment against ricin, the toxic protein of castor-bean cake. Thus, the aim of this research was to study the effect of alkaline agents (NaOH or KOH) and pH (10, 11 or 12) on the protein extract composition. Dry matter, proteins, ash, lipid and non-protein nitrogen and also macro minerals and trace elements were determined. In general, the increase in pH do not influenced neither the dry matter content (similar to 93.3 %) nor the non-protein nitrogen content, but influenced the protein content as consequence of the pH increasing. Similar behaviour was observed for ash content due to increasing the amount of both alkaline. The freeze-dried protein extracts presented lower lipids content (similar to s0.8 %), regardless of both alkaline agent and pH values. The nitrogen was the most abundant mineral (10 %) in the protein extracts for all the extraction conditions, while the other macro minerals contents were lower than 1.0 %. With respect to the trace elements, iron was the most abundant independently of the alkaline agent used. We can concluded that the protein extracts are protein concentrates, and the protein content increased with increasing extraction pH. The alkaline agent NaOH was slightly more effective for protein extraction. (AU)

• FAPESP's process: 08/11341-5 - Development of biodegradable material based on Castor (Ricinus communis L.) cake, a by-product of the bio-diesel agroindustrial chain
• Grantee: Paulo José do Amaral Sobral
• Support Opportunities: Regular Research Grants
• FAPESP's process: 09/10172-8 - Development of biodegradables materials from castor protein modified by tannins and reinforced with vegetal fibers.
• Grantee: Hulda Noemi Chambi Mamani
• Support Opportunities: Scholarships in Brazil - Post-Doctoral