期刊名称：Journal of Radiation Research and Applied Sciences
印刷版ISSN：1687-8507
出版年度：2015
卷号：8
期号：2
页码：190-200
DOI：10.1016/j.jrras.2015.01.003
出版社：Elsevier B.V.
摘要：Abstract This study assessed the effect of molecular weight (MW) reduction by gamma irradiation on the antioxidant capacity of chitosan with potential application in the preservation of foodstuffs. Two batches of chitosan were obtained by heterogeneous chemical N-deacetylation of chitin from common lobster (Panulirus argus). Irradiation of chitosan was performed using a 60Co source and applying doses of 5, 10, 20 and 50 kGy with a dose rate of 10 kGy/h. Attenuated Total Reflection Fourier Transform Infrared Spectroscopy was used to identify main chemical features of chitosan. The average viscosimetric \{MW\} was determined by the viscosimetric method while the deacetylation degree by a potentiometric method. Thermogravimetric analysis and differential scanning calorimetry were conducted to evaluate the thermal degradation behavior of the chitosan samples, both under nitrogen flow. The antioxidant activity of chitosan solutions at 1% (w/v) in lactic acid at 1% (v/v) and Tween 80 at 0.1% (v/v) was evaluated through the \{ABTS\} assay and scavenging of \{DPPH\} radical by chitosan. The increase of irradiation dose with 60Co until 50 kGy decreased significantly the \{MW\} of chitosan through the scission of glycosidic bonds without affecting its functional groups, while the \{DD\} (72–75 %) did not vary (p > 0.05). The \{AC\} of the chitosan solutions increased with the reduction of \{MW\} of chitosan by gamma irradiation.
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