Some Properties of Cross‐bonded Phosphate Diester of Waxy Maize Starch

Phosphate diesters of waxy maize starch were prepared by crossbonding reactions using various concentrations of phosphorus oxychloride (POCl 3 ) under conditions of controlled pH and temperature in order to have the modified starch with better functional properties. The waxy maize starch treated with 350 ppm POCl 3 (D. B.) showed higher paste viscosity and better heat resistance and acid proofing at a range of pH 3.0–4.0 than the unmodified starch and the other diesters prepared using 250–1,000 ppm POCl 3 . The viscosity at 25°C of 4% pastes, added salt, sugar and acid simulating a kind of brown sauce and cooked at 95°C for 10 min, containing the diester prepared by either 350 or 1,000 ppm POCl 3 , was higher and more stable in a refrigerator up to 4 months than that of the unmodified waxy maize starch. Application of the diester (1,000 ppm POCl 3 ) to an effective thickener for “instant Miso soup” was also investigated.