Valorisation of Jatropha curcas: Solubilisation of proteins and sugars from the NaOH extracted de-oiled press cake

• Published in: Industrial crops and products Vol. 34; no. 1; pp. 972 - 978
• Main Authors: Kootstra, A. Maarten J., Beeftink, Hendrik H., Sanders, Johan P.M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-07-2011
• Subjects: acid pretreatment; antinutritional factors; biomass; Byproducts; crop; Hydrolysis; Jatropha curcas; Lignocellulose; Maleic acid; products; Protein solubilisation; Sugar solubilisation; Valorisation; NEDO-JPC; Hydrolysis; Sugar solubilisation; DO-JPC; Protein solubilisation; Lignocellulose; Maleic acid; JPC; Valorisation; Jatropha curcas
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2011.03.007

► We investigate valorisation of press cake of
Jatropha curcas. ► We apply neutral and acidic hot treatments to increase protein solubilization. ► We also focus on value of polysaccharide fraction and total combustion value. ► Protein valorisation is similar for neutral and acidic treatment: circa 8 €/tonne cake. ► Lignocellulose is somewhat recalcitrant to acid treatment, but shows possibilities.
In this study, we investigated the possibilities for increasing the valorisation of de-oiled
Jatropha press cake (DO-JPC). The studied raw material is the by-product of the alkaline protein extraction of the DO-JPC: NaOH Extracted DO-JPC (NEDO-JPC). Protein solubilisation of NEDO-JPC was performed under neutral and acidic conditions (pH 2, 100
mM maleic acid), at elevated temperature (100, 120, and 140
°C), and at 5% (w/w) dry solids loading. After the treatment, the amount of solubilised protein was determined, as well as the solubilisation of polymeric sugars and formation of sugar degradation products furfural and 5-hydroxymethylfurfural (HMF). Although a clear influence is shown for temperature, no difference in protein solubilisation was found between treatments at pH 7 and pH 2. A maximum of 25% (w/w) of the available protein was solubilised, at 140
°C. The lignocellulose fraction of NEDO-JPC proved relatively recalcitrant to acid hydrolysis, suggesting a more intense treatment to be necessary to sufficiently increase accessibility for cellulolytic enzymes in a lignocellulosic bioethanol process. At €8.00 per tonne DO-JPC, it is concluded that the possibilities for valorisation of the protein fraction of NEDO-JPC at neutral and acid pH are limited, leaving the lignocellulose fraction as a source of valorisation to be investigated.