Characterization of Seed Protein Fractions fromCastaneaspp

Seed proteins of Castanea sativa and C. crenata were extracted by sequential procedures. Albumins accounted for over 20% of the total protein. Globulins were the main storage proteins and represented close to half of the total protein. Addition of 2-mercaptoethanol was essential for maximum extraction of the globulins, a fraction with an amino acid composition similar to that of the 1 IS storage protein from legumes. Negligible amounts of prolamins (<3%) were present in the seeds. Glutelins represented just under 30% of the total protein. The protein fractions were characterized by electrophoresis in polyacrylamide gels. The glutelin fraction contained unextracted globulins even when 2-mercaptoethanol was used.