Reddy Chagam Koteswara, Suriya M, Vidya P V, Vijina K, Haripriya Sundaramoorthy
Department of Food Science and Technology, Pondicherry Central University, Puducherry 605014, India.
Department of Food Science and Technology, Pondicherry Central University, Puducherry 605014, India.
Int J Biol Macromol. 2015 Aug;79:309-15. doi: 10.1016/j.ijbiomac.2015.05.003. Epub 2015 May 12.
Gamma irradiation is one of the effective techniques able to alter structure and its properties of starch. In this research, the effect of modification in terms of molecular structure and physico-chemical properties of Amorphophallus paeoniifolius starch by γ-irradiation using (60)Co as γ-source at doses of 5, 10, 15, 20 and 25 kGy with dose rate 2 kGy/h was studied. Morphology of native and irradiated starches under scanning electron microscope revealed that granules are round, elliptical and polygonal in shape with smooth surfaces; no cracking or roughness was noted on irradiated starches. Amylose content, pH, swelling power of the starches and syneresis of the gelatinized starch were significantly decreased by irradiation; while carboxyl content, solubility, light transmittance and water absorption capacity of the starch granules were raised with increased dose of irradiation. Reduced pasting parameters and changes in FTIR spectrum significantly differed from each other. XRD pattern of irradiated starches showed C-type pattern with intermediate peaks of 2θ at 16.92° and 18.12°, strong peaks of 2θ at 23.05° and weak peaks of 2θ at 14.7°, displaying slight decreased in the intensity of peaks in irradiated starches. Irradiation of starches increased gelatinization temperatures and enthalpy value was measured using DSC.
伽马辐照是能够改变淀粉结构及其性质的有效技术之一。在本研究中，以⁶⁰Co作为γ源，剂量率为2 kGy/h，研究了5、10、15、20和25 kGy剂量的γ辐照对魔芋淀粉分子结构和理化性质的改性效果。扫描电子显微镜下天然淀粉和辐照淀粉的形态表明，颗粒呈圆形、椭圆形和多边形，表面光滑；辐照淀粉上未观察到裂纹或粗糙度。辐照显著降低了淀粉的直链淀粉含量、pH值、膨胀力和糊化淀粉的离浆率；而淀粉颗粒的羧基含量、溶解度、透光率和吸水能力随着辐照剂量的增加而提高。糊化参数的降低和傅里叶变换红外光谱的变化彼此显著不同。辐照淀粉的X射线衍射图谱显示为C型图谱，2θ的中间峰在16.92°和18.12°，2θ的强峰在23.05°，2θ的弱峰在14.7°，辐照淀粉中峰的强度略有降低。淀粉辐照提高了糊化温度，并使用差示扫描量热法测量了焓值。
