Gelatin is the putative research hotspot of natural products, but gelatin prepared by traditional alkali methods has seriously affected its applications due to the worryingly low molecular weight and poor gel strength. Herein, we took the lead to extract the distinct gelatin from a kind of bioinspired collagen aggregate (CA) by a two-step controlled degradation method. Structural analysis suggested that the CA better preserves the natural aggregated structure of nature collagen (typical D-periodic cross-striated pattern). Compared with the gelatin gelatinized by the conventional alkali method (G-Al) and commercial gelatin (CG), the gelatin (G-CA) from CA had a wide molecular weight distribution range, high transparency, high viscosity, and strong gel strength as expected. Meanwhile, the G-CA film exhibited better mechanical performance and thermostability than CG and G-Al films, and water vapor permeability was also higher in the G-CA film, whereas water solubility was higher in the CG and G-Al films. Thus, the G-CA film is more conducive to the use of food packaging or edible films, exhibiting more potential market application prospects. Notably, G-CA based on CA from waste hide offal provides a way to reuse leather waste resources and further realize green and clean production in leather industry.
Keywords: D-periodic cross-striated pattern; collagen aggregate; film; gelatin; two-step controlled degradation method.