Polesi Luís Fernando, Sarmento Silene Bruder Silveira, Moraes Jaqueline de, Franco Célia Maria Landi, Canniatti-Brazaca Solange Guidolin
Department of Food Engineering, Federal University of Rondônia, Av. Tancredo Neves, 3450, 76872-862 Ariquemes, RO, Brazil.
Department of Agri-food Industry, Food and Nutrition, Luiz de Queiroz College of Agriculture, University of São Paulo, Av. Pádua Dias 11, CP 9, 13418-900 Piracicaba, SP, Brazil.
Food Chem. 2016 Jan 15;191:59-66. doi: 10.1016/j.foodchem.2015.03.055. Epub 2015 Mar 21.
This work evaluated the physicochemical and structural properties of rice starch of the cultivars IAC 202 and IRGA 417 modified by irradiation. Starch samples were irradiated by (60)Co in doses 1, 2 and 5kGy, on a rate of 0.4kGy/h. A control not irradiated was used for comparison. The granule morphology and A-type X-ray diffraction pattern were not altered by irradiation. There was an increase in amylose content, carboxyl content and acidity with irradiation. Gamma radiation did not affect the thermal properties of IAC202, but increased gelatinization temperature of IRGA417, in the higher dose (5kGy). The number of long chains of amylopectin was reduced and short chains were increased for IAC202, whereas for IRGA 417, the opposite was observed, probably due to cross-linking of starch chains. Starches had their physicochemical and structural properties modified by irradiation differently.
本研究评估了经辐照改性的IAC 202和IRGA 417品种水稻淀粉的物理化学和结构性质。淀粉样品以0.4kGy/h的速率，分别用1、2和5kGy的剂量进行（60）Co辐照。使用未辐照的对照样品进行比较。辐照未改变颗粒形态和A型X射线衍射图谱。随着辐照，直链淀粉含量、羧基含量和酸度增加。γ辐射不影响IAC202的热性质，但在较高剂量（5kGy）下增加了IRGA417的糊化温度。对于IAC202，支链淀粉的长链数量减少，短链数量增加，而对于IRGA 417，则观察到相反的情况，这可能是由于淀粉链的交联所致。淀粉的物理化学和结构性质因辐照而发生不同程度的改变。
