Radio‐sensitivity of some starches treated with accelerated electron beam

Abstract

The paper presents the investigation of the sensitivity and degradation rate of corn, wheat, rice, and potato starches exposed to accelerated electron beam taking into consideration the paste apparent viscosity and MW distribution. The functional radiosensitivity of starch defined by analyzing the apparent viscosity behavior of its aqueous paste as a function of absorbed dose had the following order: potato>wheat>corn>rice. In a similar manner, the structural radiosensitivity of starch based on the degradation rate of the MW fractions was considered. Two slight different orders were found as (1) potato>wheat>corn>rice taking into account the number molecular fraction and (2) wheat>corn>potato>rice considering the weight molecular fraction, assigned to the different structural organization of the investigated starches.

Degradation of amylose by ionizing radiation processing

“…Irradiated and unirradiated samples were analyzed by GPC using Breeze system (Waters, USA) consisting in 1525 binary pump, autosampler 717+, 2414 differential refractive index detector, in‐line degasser AF, and temperature module system. Sample preparation was performed according to Nemtanu and Brasoveanu . Briefly, amylose (10 mg) was wetted with 20 μL ethanol and dispersed in 500 μL of 1 M NaOH.…”

“…During the latter decade, the effect of ionizing radiation (γ‐rays and electron beam) on the molecular structure of natural polymers like carrageenan , glucomannans , chitosan , starch , cellulose , was widely investigated under different conditions (i.e., in solution or in solid state, in air or under vacuum). However, most of such investigations have been carried out in aqueous solution since the effects can be spectacular due to action of very reactive chemical species (i.e., HO radicals, H atoms) as a result of the water radiolysis.…”

Aspects on Starches Modified by Ionizing Radiation Processing

“…Likewise, the apparent viscosity of irradiated starches decreased significantly as the irradiation dose increased for different cereal and tuber starches [4,5,8,10,11]. Kamal et al [8] demonstrated that the electron beam effect on the apparent viscosity of corn starch was greater than that of gamma radiation in the early stage of irradiation ~5 kGy.…”

“…Kamal et al [8] demonstrated that the electron beam effect on the apparent viscosity of corn starch was greater than that of gamma radiation in the early stage of irradiation ~5 kGy. Moreover, a mathematical model was elaborated to describe the exponential decrease of the apparent viscosity against irradiation dose [4]. At the same time, it was proved that each starch is characterized by a material constant that indicates the functional sensitivity of starch to irradiation.…”

“…Molecular weight of polymers influences most of their physicochemical and functional properties, and its investigation can reveal information useful to understand the behavior of macromolecules to ionizing radiation processing. Unfortunately, one can notice the lack of interest in this subject and the existence of only a few papers [4,5,12,17] that have approached the study of the influence of the electron beam or gamma radiation on the starch molecular weights. The experimental data showed the decreasing evolution of the molecular weights with the irradiation dose independently of the starch botanical source.…”