Quantitative Analysis of Chemically Modified Starches by 1 H‐NMR Spectroscopy

A quantitative 1 H‐NMR method for the determination of the Molar Substitution ( MS ) of acetylated and hydroxypropylated starches was developed and tested for MS ranging from 0.09 to 0.5. Results were checked using the Johnson method and a titration method for hydroxpropylated and acetylated starch, respectively. Hydroxypropylated starch was produced using both a static mixer reactor (SMX type) and a co‐rotating twin screw extruder. Acetylated starch was produced using a counter‐rotating twin screw extruder. Quantitative analysis results of the 1 H‐NMR method were in good agreement with traditional analysis methods for all samples tested. Main advantage of the 1 H‐NMR method is the considerable time saving as compared to the traditional analysis methods.