30C-31 |
Seed storage proteins from mexican piñoncillo |
A. L. MARTÍNEZ-AYALA, M. Sánchez Rivera, J. Martínez Herrera, and S. L. Rodríguez Ambriz. Biotecnology, Centro de Desarrollo de Productos Bióticos-I.P.N., Carr. Yautepec-Jojutla Km 8. Col San Isidro. Yautepec, Morelos. México, Yautepec, Morelos, 62731, Mexico The storage proteins in seed are very important in the germination stage and are also of immense nutritional importance. This proteins are known as globulins, albumins, prolamins and glutelins. The Jatropha curcas seed also known as purging nut, etc., depending on the region, is a member of Euphorbiaceae family. In Mexico it's meet as piñon or piñoncillo by the people living from Veracruz state, the seeds after roasting, are also consumed. This seed contains up to 60% oil and 20% protein and the amino acid profile shows high levels. In this work, the storage proteins were fractionated and characterized with respect to subunit composition and molecular mass. The seeds of J. curcas were collected in experimental field of CeProBi from Yautepec, Morelos. The protein fractions were obtained using seed meal (kernels deoiled using hexane). The crude protein and lipid were determined using the AOAC procedures. Protein fractionation was carried out by the method of Osborne as modified by Texeira and Ferreira. Electrophoresis (SDS-PAGE) was performed for each fraction. The results showed high protein content in defatted flour and full fat flour; 52.1 and 27.4%; respectively. Fat content was 19.4%in defatted flour and 59.8% in full fat flour. Storage protein is composed of 44.4% globulins, 12.3% albumins, 3.4% prolamins and 39.8% glutelins. In SDS-PAGE, the albumin fraction represents four main components <30 KDa, globulin fraction is composed of six major bands: four between 30 to 70 kDa and two <20 kDa. The prolamins were fractionated in three bands and glutelins were constituted only by two bands of 33 and 27 KDa. Results suggest that the main fraction (globulins) in Jatropha seeds is similar to the globulins in some legumes; and the albumins showed a component with molecular mass as the 2S albumin S-rich. The study of this proteins could be important, for its possible incorporation in the human and animal diet.
Session 30C, Food Chemistry: Proteins
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