High-stretchable, transparent, degradable and anti-drying gelatin hydrogel for mango preservation

The emerging hydrogels for fruit preservation have aroused widespread scientific interest. However, it is challenging for current hydrogel packaging to incorporate the required multifunctional properties. Herein, a gelatin-based (Gel/G) hydrogel film is elaborately designed as an efficient mango packaging and preservation system. Multiple dynamic non-covalent interactions serve as sacrificial bonds to dissipate energy and endow the hydrogel with remarkable elongation (up to 1204 %) and tensile strength (216.08 kPa). The optimized Gel/G hydrogel also provides excellent transparency, UV blocking, degradability, water vapor barrier, biosafety and anti-drying performance. Notably, compared with the blank control and commercial PE film, the Gel/G hydrogel-packed mangoes maintain the color and smoothness of epidermis, and delay the browning and softening processes of fruits. Additionally, the pH value, TSS, and MDA contents of Gel/G hydrogel-packed mangoes remain at a lower level and vary stably, and TA consumption is less. These results suggest that the Gel/G hydrogel packaging has a remarkable effect on mango preservation and can effectively delay its ripening and senescence process. Therefore, our work contributes to the in-depth understanding and rational design of food packaging and multifunctional hydrogel preservation films.