Triple-induced gardenia fruit extract-enriched gelatin/polysaccharides microgels for O/W emulsions, and food 3D printing

Gardenia fruit extract like gardenia blue is untable under light exposure and its application need expansion. Gardenia blue was proposed to be stabilized in triple-induced microgels from cooperative effects of gelatin, β-cyclodextrin and chitooligosaccharide, and its emulsifying ability and 3D printing potential were subesequently explored. The synergetic effects on gardenia blue due to the intermolecular interactions including hydrogen bonding and electrostatic interaction, contributed to the high UV irradiation stability of complexes. The complex microgels could absorb onto oil-water interface with emulsifying property, and the obtained high internal phase emulsions (HIPEs) illustrated outstanding centrifugal stability and great storage stability with low and uniform optical microscopic droplet diameters. The obtained HIPEs possessed excellent shearing thinning properties, excellent structure reversibility, high-degree reticulation, outstanding thixotropy, great elasticity, high cohesive energy and mechanical strength. 3D printing of HIPEs onto food also demonstrated high shape fidelity with low deviation. The findings illustrate the way of stabilizing gardenia blue in microgels by triple synergies, demonstrate the potential as stabilizer for developing HIPEs, and offered reference for highly-added-value utilization in the personalized 3D food products.