Preparation of milk protein-vitamin A complexes and their evaluation for vitamin A binding ability

- Succinylated sodium caseinate and succinylated milk protein concentrate were prepared.
- 3.2 mol of succinic anhydride/mole of lysine gave maximum degree of succinylation.
- Ammonium sulphate precipitation was used for the estimation of unbound vitamin A.
- Different milk protein were evaluated for ability to bind vitamin A.
- Effect of complexation on solubility of protein and vitamin A was carried out.

The recent trends for consumption of low fat and fat free foods have led to an increase in deficiencies of vitamin A. Vitamin A is susceptible to light and heat and thus require stabilization in aqueous medium. Stability can be improved by binding of vitamin A to milk protein. In the present research work, succinylated milk proteins were also prepared. 3.2 mol of succinic anhydride/mole of lysine content gave maximum degree of succinylation for both sodium caseinate and milk protein concentrate. Native, reassembled and succinylated milk proteins were used for the preparation of milk protein-Vitamin A (Vit A) complexes. These complexes were further evaluated for unbound vitamin A, ability of milk protein to bind vitamin A and solubility of protein and vitamin A as affected by complexation. Estimation of unbound vitamin A in milk protein-Vit A complexes was carried out using ammonium sulphate for precipitation.