Efficient and eco-friendly method of gelatin production from bovine hide by acid-thermal treatment and protease-aided process: one-pot biocatalysis approaches

To simultaneously achieve high yield and high gel strength in gelatin derived from bovine hide, an enzymatic preparation process was investigated in this study. This process was developed based on the assessment and optimization of the hydrolytic performance of selected proteases on acid-thermal denatured hide collagen. Subsequently, a one-pot technology for gelatin preparation was developed by optimizing the hydrolysis conditions of the selected acid protease, which integrates the conventional process of acid washing, deacidification, gelatin extraction and desalting into a single operation. The results indicated that the appropriate selection of acid proteases could improve both the gelatin yield and its gel strength. Under the optimal conditions of 40 °C, pH 4.0, acidic protease dosage of 350 U/g, and constant-temperature stirring for 6 h, the gelatin yield increased to 92.7%, the gel strength reached 210.0 Bloom g, and the other physicochemical properties of the resulting products fulfilled the requirements of industrial gelatin (QB/T 1995–2024). Moreover, the total water consumption, wastewater discharge, acid usage, and energy consumption decreased by approximately 78.9%, 100.0%, 90.0%, and 28.6%, respectively, and the energy consumption during the gelatin drying process achieved a 63.5% reduction. This study provides technical support for efficient utilization and green development of animal hides/skins resources.