Properties of some citrus seeds. Part 1. Physico-chemical characteristics of proteins

The protein solubility of some citrus seeds flours as well as physico chemi cal characteristics were determined by gel filtration, polyacrylamide gel e lectrophoresis (PAGE), polyacrylamide gel electrophoresis in the presence o f sodium dodecylsulphate (SDS-PAGE), and UV-spectrum. The highest solubilit y was in 0.1 M NaOH followed by both 0.1 M KCl and NaCl, respectively. The lowest solubility was in water. The protein solubility showed a minium with shift towards the acidic side in presence of 0.1 M and 0.5 M NaCl. The PAG E pattern showed two major protein fractions for citron, orange and mandari n seeds. SDS-PAGE proved presence of 3 major polypeptide chains in all seed s proteins. The apparent molecular weight was 37304, 23516 and 16740 dalton s, respectively. Also, the major protein fraction in all samples was globul in. The polypeptide chains were 4 for both albumins and globulins, 3 and 2 for prolamins and glutelins, respectively. Gel filtration revealed four pea ks in all samples. The major peaks were eluted at 79 and 160 ml. All peaks were principally free from nucleic acids except peak No. 4.