Abstract
The viscograms of linseed oil-treated potato starch were greatly changed by difference of the oil with γ-irradiation. The viscograms of the irradiated potato starch containing 2.28% oil showed that the maximum viscosity at 40 krad was slightly larger than that of the control (non-irradiated sample) and moreover at the dosage of more than 80 krad it was less than that of the control. On the other hand, the viscograms of the irradiated potato starch containing 4.92% oil showed that the maximum viscosity greatly decreased compared with that of the control. In the viscograms of the irradiated corn starch containing 3.5% oil, the maximum viscosity first increased at 40 krad compared with that of the control and then it decreased gradually with an increased dose of irradiation. In the viscograms of the defatted samples of both starches with and without oil treatment before irradiation, the maximum viscosity decreased gradually with an increased dose of irradiation. Moreover, the ratio of decrease of maximum viscosity under irradiation was greater in the oil treated sample than it was in the untreated. The same was the true in the case of the mean DP and the β-amylolysis. These results suggested that the decomposition of starch molecules by γ-irradiation was enhanced by linseed oil in starch granules.
