STRUCTURAL-CHANGE OF POTATO STARCH GRANULES BY BALL-MILL TREATMENT

Molecular change of potato starch granule by ball-mill treatment was i nvestigated. Starch granule still retained its whole figure after 320h , treatment, but its surface changed extremely rough. Water absorption activity extremely increased by 10h treatment. Amylase susceptivity o f starch increased according to treatment time. X-ray diffraction patt ern lost its peak and enthalpy on DSC decreased 70% after 20h treatmen t. Iodine color reaction value decreased 30% and lambda max shifted hy pso-chromic 15 nm in the both cases of debranched and non-debranched s amples after 20h treatment, and this indicates amylose was also degrad ed by the treatment. However, the peak of amylose decreased 10% and th e peak of amylopectin decreased 10% on each GPC of branched and non-de branched samples after 20h treatment. GPC (Toyopearl HW-65) of 320h tr eated sample shows only one peak, but its debranched sample shows simi lar pattern to that of non-treated sample on HPAEC. C-13-solid state N MR spectra suggest that total disruption frequency is fairly low after long this treatment.