QUANTITATIVE-ANALYSIS OF DEBRANCHED AMYLOPECTIN BY HPAEC-PAD WITH A POSTCOLUMN ENZYME REACTOR

The chain-length distribution of debranched amylopectin was analyzed b y using high performance anion-exchange chromatography with an amylogl ucosidase (AMG) reactor and a pulsed amperometric detector (HPAEC-ENZ- PAD). The effects of reactor length, reactor temperature, and addition al alpha-amylase reactor were studied. Results showed that a 2 mm i.d. x 23 mm AMG reactor at 25 degrees C was sufficient to convert HPAEC-s eparated amylodextrins to glucose; the PAD response for the hydrolyzed amylodextrins of different chain-length was consistent, and quantitat ive results were achieved. With this enzymatic treatment, amylodextrin with DP up to 77 was detected for a debranched tapioca amylopectin sa mple. The chain-length distribution profile of debranched tapioca amyl opectin showed three fractions with peak DPs 48 +/- 1 (F1), 19 (F2a), and 12 (F2b).