Development of Antibacterial Gels Based on Sodium Alginate and Inclusion Complexes for Packaging Applications in Fruits and Vegetables

Abstract

Abstract Bacterial growth in fruits and vegetables causes a large percentage of the loss and waste of these foods worldwide. For this reason, the objective of this study was to develop antibacterial gels based on sodium alginate, β -cyclodextrin, and allyl isothiocyanate inclusion complexes ( β -CD:AITC) for the potential packaging of fresh fruits and vegetables. The β -CD:AITC complexes were prepared by the co-precipitation method with a 1:1 molar ratio, and was further verified by FESEM microscopy. On the other hand, the antibacterial gels were prepared using the external gelation method, and the effect of the order of incorporation of the components, the conditions of the components, and the resting conditions of the dispersions on their visual appearance was evaluated. Furthermore, the antibacterial activity of the gels against Escherichia coli and Listeria innocua was evaluated using a headspace system. FESEM micrographs showed a crystalline block-like morphology in the inclusion complexes. The order of incorporation (1) glucone-delta-lactone (2) complexes (3) alginate allowed for obtaining more homogeneous gels with a smooth surface. The presence of glucono-delta-lactone, the concentration of 0.05 M CaCl2, a cross-linking time of 20 hr, and the cooling of the dispersion allowed more uniform gels to be obtained. Finally, better antibacterial activity against E. coli was obtained with the gels loaded with 10% β -CD:AITC complexes. According to these results, the developed materials could be used as antimicrobial packaging materials for fresh fruits and vegetables.

Keywords

• β-cyclodextrin, allyl isothiocyanate, alginate, food packaging, antimicrobial.