Effect of nutritional status of faba bean (Vicia faba L.) on protein solubility profiles

A field experiment was carried out to study the effect of mycorrhizal inoculation. phosphorus and sulphur fertilization, under two water regimes, on protein solubility fractions of faba bean. The major protein fraction of faba bean was the globulin fraction that ranged from 69.5 to 78.1%. Phosphorus treatment significantly (P⩽0.05) increased the globulin fraction of faba bean seeds in the wet treatment but significantly (P⩽0.05) decreased it in the dry treatment. All fertiliser treatments significantly (P⩽0.05) increased the albumin fraction in the wet treatment, whereas only treatments of mycorrhiza, mycorrhiza+sulphur and mycorrhiza+phosphorus+sulphur significantly increased it in the dry treatment compared to control. With the exception of the treatment mycorrhiza+sulphur, all other fertilisation treatments showed prolamin contents of faba bean seeds, similar to that of the control in the wet treatment. The G₃-glutelin fraction of faba bean ranged from 8.9 to 14.4%. Treatments with sulphur, mycorrhiza and mycorrhiza+sulphur significantly increased the G₃-glutelin fraction, whereas phosphorus and mycorrhiza+phosphorus treatments significantly decreased it. The insoluble protein (residue) of faba bean ranged from 1.8 to 3.4%. Generally, fertiliser treatments significantly increased the insoluble protein in the wet treatment. With the exception of treatments mycorrhiza and mycorrhiza+sulphur, all other fertiliser treatments significantly increased the insoluble protein content in the dry treatment. Water regime significantly (P⩽0.05) affected the protein fractions.