Sunder Mridula, Mumbrekar Kamalesh D, Mazumder Nirmal
Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
Department of Radiation Biology and Toxicology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
Curr Res Food Sci. 2022 Jan 7;5:141-149. doi: 10.1016/j.crfs.2022.01.001. eCollection 2022.
Starch is one of the most common and abundantly found carbohydrates in cereals, roots, legumes, and some fruits. It is a tasteless, colorless, and odorless source of energy that is present in the amyloplasts of plants. Native starch comprises amylose, a linear α-glucan having α-1,4-linkage and amylopectin, a branched polysaccharide with both α-1,4-linkage and α-1,6-linkage. Due to the low solubility, high viscosity, and unstable pasting property of native starch, it has been restricted from its application in industries. Although native starch has been widely used in various industries, modification of the same by various chemical, enzymatic and physical methods have been carried out to alter its properties for better performance in several industrial aspects. Physical modification like gamma radiation is frequently used as it is rapid, penetrates deeper, less toxic, and cost-effective. Starch when irradiated with gamma rays is observed to produce free radicals, generate sugars owing to cleavage of amylopectin branches, and exhibit variation in enzymatic digestion, amylose content, morphology, crystallinity, thermal property, and chemical composition. These physicochemical properties of the starch due to gamma radiation are assessed using optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and its application are discussed.
淀粉是谷物、块根、豆类和一些水果中最常见且含量丰富的碳水化合物之一。它是一种无味、无色、无臭的能量来源，存在于植物的造粉体中。天然淀粉由直链淀粉（一种具有α-1,4-糖苷键的线性α-葡聚糖）和支链淀粉（一种同时具有α-1,4-糖苷键和α-1,6-糖苷键的支链多糖）组成。由于天然淀粉的低溶解性、高粘度和不稳定的糊化特性，其在工业应用中受到限制。尽管天然淀粉已广泛应用于各种行业，但人们已通过各种化学、酶法和物理方法对其进行改性，以改变其性能，使其在多个工业领域表现更佳。像γ射线辐照这样的物理改性方法因其快速、穿透性强、毒性小且成本效益高而经常被使用。观察发现，淀粉在受到γ射线辐照时会产生自由基，由于支链淀粉分支的断裂而生成糖类，并在酶消化、直链淀粉含量、形态、结晶度、热性能和化学成分方面表现出变化。利用光学显微镜、扫描电子显微镜（SEM）、X射线衍射（XRD）、傅里叶变换红外（FTIR）光谱、差示扫描量热法（DSC）对γ射线辐照引起的淀粉这些物理化学性质进行了评估，并对其应用进行了讨论。
