Enzyme-assisted extraction in liquid-liquid two-phase aqueous system was applied for the first time in order to extract genipin from genipap. The effect of different commercial enzymes, their concentrations, and extraction parameters were investigated. Moreover, chitosan gels were prepared, crosslinked with glutaraldehyde or genipin and characterized by their textural and rheological properties. The crosslinked chitosan was used as support for the immobilization of model β-galactosidases. Among the different commercial enzymes tested for extraction, Celluclast 10% (36 °C and pH 3.7) provided an extraction of 196 mg.g of genipin. Chitosan gels crosslinked with genipin 0.5% showed better textural and similar rheological properties when compared to the chitosan crosslinked with glutaraldehyde 3%. The percentage of lactose hydrolysis by the immobilized K. lactis β-galactosidase using genipin as a crosslinker was 87%. Thus, the genipin obtained in this work proved to be an excellent alternative to the use of glutaraldehyde in chitosan crosslinking applications.

This study focused on the development and characterization of biodegradable films based on gelatin capsule residue crosslinked with the natural agent genipin extracted from genipap (Genipa americana L.). Their potential on maintaining the quality attributes (level of peroxides, conjugated dienes and trienes and color) of extra‐virgin olive oil under accelerated storage conditions was investigated. Results showed that the genipin‐crosslinked films had a dark blue appearance. Their total soluble matter, water vapor permeability, tensile strength, ultraviolet and visible light barriers and thermal properties were improved in relation to the uncrosslinked film, whereas their moisture content and microstructure were not affected. In general, films presented comparable properties to those of glutaraldehyde‐crosslinked films. The developed films successfully protected the packed oil from primary and secondary oxidation and maintained the color over the storage period. Therefore, this study demonstrated the effectiveness of genipin on improving the properties of gelatin‐based films and the promising application of films as food packaging.