Antioxidant Activity Improvement of Apples Juice Supplemented with Chitosan-Galactose Maillard Reaction Products
Faculty of Medicine Sousse, Department of Biochemistry, University of Sousse, Sousse 4002, Tunisia
AgroBiosciences Research Division, Mohamed VI Polytechnic University, lot 660-Hay Moulay Rachid, ben-Guerir 43150, Morocco
Laboratory of interfaces and advanced materials, Faculty of Science of Monastir, University of Monastir Monastir 5000, Tunisia
Author to whom correspondence should be addressed.
Academic Editor: Francesco Cacciola
Molecules 2019, 24(24), 4557; https://doi.org/10.3390/molecules24244557
Received: 12 October 2019 / Revised: 2 November 2019 / Accepted: 5 November 2019 / Published: 12 December 2019
Chitosan-galactose Maillard reaction (CG) were prepared by heating at 100 °C for 3 hrs in a model system containing chitosan (CH) and 1%, 1.5% and 2% (w/v) of galactose. The results showed that the absorbance at 294 and 420 nm, the fluorescence intensity and the color differences of CG Maillard reaction products (MRPs) increased significantly with the increase of galactose concentration, which indicated the development of MRPs. In addition, FT-IR analysis showed that the degree of deacetylation of CG-MRPs was reduced with the increasing galactose ratio by the schiff base (–C=N) formation, indicating that the galactose has been attached to the amino group of chitosan. Likewise, the antioxidant activities (DPPH, chelating ability and reducing power) of CG-MRPs were investigated. Notably, the effect of galactose concentration in CG-MRPs was found to enhance the antioxidant activity, indicating that CG-2% exhibited the highest antioxidant activity in the range of 0.25–2.0 mg/mL. Furthermore, the apple juice supplemented with CG-MRPs could significantly improve the antioxidant activities, and CG-2% in apple juice showed the better antioxidant capacity at the concentration of 1.0 mg/mL. Thus, we conclude that CG-MRPs addition may greatly improve the antioxidant quality of apple juice.