This study investigated the effect of gamma radiation on the digestibility and functional properties of rice starch.Rice cultivars IRGA417 and IAC202 were used for isolation of starch by the alkaline method.Starch sam...This study investigated the effect of gamma radiation on the digestibility and functional properties of rice starch.Rice cultivars IRGA417 and IAC202 were used for isolation of starch by the alkaline method.Starch samples were irradiated with 1,2 and 5 k Gy doses of ^(60)Co at a rate of 0.4 k Gy/h.A control sample,which was not irradiated,was used for comparison.Irradiated and control starches were characterized by in vitro starch digestibility,total dietary fiber,color,water absorption index,water solubility index,syneresis,swelling factor,amylose leaching,pasting properties and gel firmness.Irradiations changed starch digestibility differently in either cultivar.Increasing radiation doses promoted increase in the color parameter b*(yellow),elevation in the capacity to absorb water,and solubility in water as well as the amylose leached from granules for both cultivars.Pasting properties showed a decrease that was proportional to the dose applied,caused by the depolymerization of starch molecules.Gel firmness of the starch from IAC202 was inversely proportional to the radiation dose applied,whereas for IRGA417,there was a reduction at 5 k Gy dose.Rice starches can be modified by irradiation to exhibit different functional characteristics and they can be used by the food industries in products such as soups,desserts,flans,puddings and others.展开更多
基金the Post Graduate Program of Center for Nuclear Energy in Agriculture(CENA/USP)for the financial and academic supportthe‘Comissao Nacional de Energia Nuclear’(CNEN),Brazil for the scholarship
文摘This study investigated the effect of gamma radiation on the digestibility and functional properties of rice starch.Rice cultivars IRGA417 and IAC202 were used for isolation of starch by the alkaline method.Starch samples were irradiated with 1,2 and 5 k Gy doses of ^(60)Co at a rate of 0.4 k Gy/h.A control sample,which was not irradiated,was used for comparison.Irradiated and control starches were characterized by in vitro starch digestibility,total dietary fiber,color,water absorption index,water solubility index,syneresis,swelling factor,amylose leaching,pasting properties and gel firmness.Irradiations changed starch digestibility differently in either cultivar.Increasing radiation doses promoted increase in the color parameter b*(yellow),elevation in the capacity to absorb water,and solubility in water as well as the amylose leached from granules for both cultivars.Pasting properties showed a decrease that was proportional to the dose applied,caused by the depolymerization of starch molecules.Gel firmness of the starch from IAC202 was inversely proportional to the radiation dose applied,whereas for IRGA417,there was a reduction at 5 k Gy dose.Rice starches can be modified by irradiation to exhibit different functional characteristics and they can be used by the food industries in products such as soups,desserts,flans,puddings and others.
