No abstract

Legume seeds (soy bean, lupin and bean seeds) were soaked in 0.5% sodium bicarbonate in attempt to evaluate their nutritional quality and protein solubility index. Soaking process led to an increase in the hydration coefficient, seed weight, total protein, ash, fat, fiber, while non protein nitrogen, total carbohydrates, starch, stachyose, raffinose, reducing sugars, and minerals (except Na) were decreased. All antinutritional factors such as phytic acid, tannin, trypsin inhibitor and hemagglutinin activity were decreased during soaking in 0.5% sodium bicarbonate; it was the same for the protein solubility in different solutions, while the in-vitro protein digestibility and available lysine were increased.

The chemical composition and minerals content of citrus seeds and its flours, the characteristics and structure of citrus seed oils as well as nutritional properties were studied. The citrus seeds and its flours were rich in oil and protein, respectively. Both citrus seeds and flours proved to be a good source for minerals K, Ca, P, Na, Fe and Mg. The flours of citrus seeds were rich in leucine, valine, total aromatic and total sulfur amino acids compared to FAO/WHO reference. Refractive index, specific gravity, melting point, colour and viscosity of citrus seeds oils differed slightly. Citrus seed oils had eight classes, according to the results of thin‐layer chromatogram. Triglycerides were the major oil class in all samples. The citrus seeds oil samples contained eight fatty acids while linoleic, oleic and palmitic acids were major acids. Some antinutritional compounds were detected in the flours. The results revealed that, glucosides, stachyose, raffinose, trypsin inhibitor, phytic acid and tannins were present in all citrus seeds flours. The data established that all flours were completely free from any agglutination activity. The biological values, true and apparent digestibility of mandarin seed protein were the lowest among all citrus seeds proteins by all measurements except the PER equations.

The protein solubility of some citrus seeds flours as well as physico‐chemical characteristics were determined by gel filtration, polyacrylamide gel electrophoresis (PAGE), polyacrylamide gel electrophoresis in the presence of sodium dodecylsulphate (SDS‐PAGE), and UV‐spectrum. The highest solubility 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 PAGE pattern showed two major protein fractions for citron, orange and mandarin seeds. SDS‐PAGE proved presence of 3 major polypeptide chains in all seeds proteins. The apparent molecular weight was 37 304, 23 516 and 16 740 daltons, respectively. Also, the major protein fraction in all samples was globulin. The polypeptide chains were 4 for both albumins and globulins, 3 and 2 for prolamins and glutelins, respectively. Gel filtration revealed four peaks 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.

The protein solubility of some citrus seeds flours as well as physico‐chemical characteristics were determined by gel filtration, polyacrylamide gel electrophoresis (PAGE), polyacrylamide gel electrophoresis in the presence of sodium dodecylsulphate (SDS‐PAGE), and UV‐spectrum. The highest solubility 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 PAGE pattern showed two major protein fractions for citron, orange and mandarin seeds. SDS‐PAGE proved presence of 3 major polypeptide chains in all seeds proteins. The apparent molecular weight was 37 304, 23 516 and 16 740 daltons, respectively. Also, the major protein fraction in all samples was globulin. The polypeptide chains were 4 for both albumins and globulins, 3 and 2 for prolamins and glutelins, respectively. Gel filtration revealed four peaks 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.