%0 Journal Article
%T Sequentially Integrated Optimization of the Conditions to Obtain a High-Protein and Low-Antinutritional Factors Protein Isolate from Edible Jatropha curcas Seed Cake
%A Liliana Le¨®n-L¨®pez
%A Gloria D¨¢vila-Ortiz
%A Cristian Jim¨¦nez-Mart¨ªnez
%A Humberto Hern¨¢ndez-S¨¢nchez
%J ISRN Biotechnology
%D 2013
%R 10.5402/2013/197201
%X Jatropha curcas seed cake is a protein-rich byproduct of oil extraction which could be used to produce protein isolates. The purpose of this study was the optimization of the protein isolation process from the seed cake of an edible provenance of J. curcas by an alkaline extraction followed by isoelectric precipitation method via a sequentially integrated optimization approach. The influence of four different factors (solubilization pH, extraction temperature, NaCl addition, and precipitation pH) on the protein and antinutritional compounds content of the isolate was evaluated. The estimated optimal conditions were an extraction temperature of 20¡ãC, a precipitation pH of 4, and an amount of NaCl in the extraction solution of 0.6£¿M for a predicted protein content of 93.3%. Under these conditions, it was possible to obtain experimentally a protein isolate with 93.21% of proteins, 316.5£¿mg 100£¿g£¿1 of total phenolics, 2891.84£¿mg 100£¿g£¿1 of phytates and 168£¿mg 100£¿g£¿1 of saponins. The protein content of the this isolate was higher than the content reported by other authors. 1. Introduction Jatropha curcas is a tree of the Euphorbiaceae family which has been used, due to the high oil content (40¨C60%) of its seeds, as an alternative source of biodiesel [1]. The residual seed cake is a low-value byproduct left after oil extraction which, however, has a high protein content [2]. This seed cake, also, is highly toxic to a number of animal species due to the presence of different types of antinutritional components such as phytic acid, trypsin inhibitors, phenolic compounds, lectins (curcin), and saponins in high amounts [3, 4]. In addition to these, phorbol esters have been identified as one of the main compounds responsible for J. curcas toxicity [5]. These compounds are referred to as tigliane diterpenes in which two hydroxyl groups are esterified to fatty acids and are well known for their tumor promoting activity [6]. However, edible or nontoxic provenances have been reported to exist in Mexico [3, 7] which contain negligible amounts of phorbol esters though the levels of the other antinutritional compounds are similar to those found in the toxic varieties [8]. This would allow the seed meal from edible varieties to be processed and used as an economic source of protein for both humans and animals. Plant protein isolates are very important in the food industry due to their high protein contents, which can reach 90%. They are commonly prepared from oilseeds, legumes, and their defatted seed meals. The methods of preparation generally include the solubilization
%U http://www.hindawi.com/journals/isrn.biotechnology/2013/197201/