Preparation of low-citric acid-substituted starches

Low-citric acid substituted starches were produced using the method described by Agboola et al. (1991). Starch (300 g) was suspended in 400 mL of distilled water, and about 10 mL of 1 M NaOH was used to adjust the pH of the slurry to about 9. The alkaline slurry was held for 30 min with occasional stirring. A 15% citric acid monohydrate and 1% H₂SO₄ (both based on starch dry weight) mixture was made up to 100 mL with distilled water. The mixture was added to the alkalized slurry and held for 5 h at room temperature (28 ± 2 °C) and then washed with 600 mL of distilled water, filtered, dried at 50 °C for 24 h, milled, packaged and stored.