Functional properties of plant proteins Part 6. Some functional properties of succinylated protein isolates from sunflower seed (Helianthus annuus L.)

✍ Scribed by Schwenke, K. D. ;Rauschal, E. J.

• Publisher: John Wiley and Sons
• Year: 1983
• Tongue: English
• Weight: 529 KB
• Volume: 27
• Category: Article
• ISSN: 0027-769X
• DOI: 10.1002/food.19830271025

✦ Synopsis

The reaction of raw globulin preparations from sunflower seed with a 10-30-fold excess of succinic anhydride results in a maximum blockage of 85-92 % of the protein amino groups.

The water absorption of the protein increases 2-fold after a 26 % succinylation and nearly 6-fold after an exhaustive modification. The oil absorption decreases after a moderate (42 %) succinylation of the protein and reaches the value of unmodified protein after being exhaustively modified.

The emulsifying capacity (EC) is highest in the native unmodified protein. Treatment with acidic aqueous butanol for removing phenolic compounds results in a decrease of EC. The latter increases again after an exhaustive succinylation of butanol-treated protein. A high level of modification ( 8 6 7 %) improves the emulsifying activity and the emulsion stability of the protein. Succinylation increases the foam capacity but does not influence the high foam stability of the protein.

A broadening of the solubility minimum and a shift of its position from pH 4.5-5.5 to pH 2.5-4.8 takes place at high levels of chemical modification.

Relations are discussed between the dissociation of the protein into the subunits at a high level of substitution ( 2 80 %) determined by gel electrophoresis and the functional properties.