The effect of phytate on the solubility of the sunflower seed proteins

Abstract

11S protein of the sunflower seed is precipitated by phytate at pH 2.0, a protein‐phytate complex being formed thereby. The number of the phosphate groups bound by the time the precipitation is completed is less than one half of that of the basic groups of the 11S protein. The insolubility of the complex formed interferes with the acid extraction of protein from the sunflower meal and solvent cake. The protein extractability increases sharply after the removal of the phytate.

Effect of Protein – Phytate Interactions on the Solubility of Ricinodendron heudelotii (Bail.) and Tetracarpidium conophorum (Müll. Arg.) Defatted Flours

“…This difference between protein solubility and phytate solubility could help to extract more protein and eliminate the majority of phytate. This confirms the findings in sunflower seed protein (Bulmaga et al, 1989).…”

“…The lower solubility of phytate at pH 9 could be explained by the breaking of phytate -cation -protein complexes to form insoluble calcium -phytate complexes and soluble proteins. Reduction of phytate solubility at alkaline medium was also observed on soybean (de Rham and Jost, 1979) and sunflower (Bulmaga et al, 1989). …”

“…Interactions between protein and other compounds like phytates reduce protein extraction (Greiner et al, 2006). In the aim of increasing protein recovery during extraction, many studies on conventional protein sources like Helianthus sp (Bulmaga et al, 1989), Psophocarpus tetragonolobus (Sri Kantha et al, 1986) were realized in sight of reducing the formation of protein -phytate complexes.…”

Changes in free and bound chlorogenic acid and in polyphenoloxidase activity during the industrial processing of sunflower seeds (Short communication)

“…The amount of the CA bound with the kernel proteins wascalculated by substracting the amount of bound CA in the hull fraction of each sample from the total bound CA and was expressed as per cent of protein content of the sample. The protein (N x 5.7) was determined by micro-KJELDAHL digestion followed by coulometric titration [8].…”

Factors Affecting the Gelation Properties of Hydrolyzed Sunflower Proteins

“…SUNFLOWER SEEDS are a widespread protein-rich crop without toxicants or antinutritive factors other than phytate and chlorogenic acid (Bulmaga et al, 1989). Their protein is slightly deficient in lysine and threonine (Saviozzi et al, 1986).…”