| Abstract: | ABSTRACT Waxy (essentially amylose-free) maize starch was chemically modified to varying degrees by treatment with 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (CHPTAC), and the degree of cationic modification was determined by a standard wet chemistry method. FT-Raman spectra of the modified starches were taken, and a characteristic Raman band ～761 cm?1 was found. This 761 cm?1 Raman band's intensity depended on the level of cationic modification of the starch. The ratio of intensity of the ～761 cm?1 band to a ～715 cm?1 C-C stretch Raman band (used as an internal standard) was plotted versus the amount of cationic modification derived by titration analysis, and a linear fit was obtained with a correlation of 0.998. The FT-Raman spectroscopy method presented here demonstrates a rapid non-destructive way to determine the level of cationic modification of waxy maize starch, and should be suitable for use with cationic modified starches of any amylose content. |
