Study on preparation of Maillard reaction product of chitosan-glucose using irradiated chitosan and evaluation of strawberry preservation

Abstract

In this study, Maillard reaction products of chitosan-glucose (CTS/GC) solution were prepared from irradiated chitosan (CTS) depolymerised by Co-60 gamma irradiation and glucose (GC). The reaction conditions were investigated, particularly temperature, reaction time and CTS/GC ratio. The molecular weight (Mw) of irradiated chitosan samples was determined by gel permeation chromatography (GPC). The results showed that the molecular weight of chitosan irradiated in a non-H₂O₂ environment (in the swollen state with water) decreased more slowly than the molecular weight of CTS in the swollen state with H₂O₂ due to the synergistic effect of using gamma Co-60 and H₂O₂, which effectively degraded chitosan to create oligochitosan more efficiently than each agent, chitosan-glucose solution with ratio of CTS/GC 1:1 (w/w), reaction time in 2 hours at 90^oC had the highest optical density at 420 nm. The possibility of prolonging the storage life of strawberries was also investigated. Applying CTS8/GC solution to treat strawberries has prolonged the preservation time approximately 2 times longer than the control. Using a 0.1% concentration of CTS8/GC solution to treat strawberries, the storage time of strawberries can be extended up to 7 days when stored at room temperature.