Sustainable ferritin from bovine by-product liver as a potential resource: Ultrasound assisted extraction and physicochemical, structural, functional, and stable analysis.

Ferritin is an iron-containing protein that is widely present in all organisms and has the function of regulating the metabolic balance of iron in organisms. It can be separated from animal by-product tissues and converted into value-added components to promote the development of a circular economy. This study established a method for extracting bovine liver ferritin (BLFer) using ultrasound-assisted buffer system. The optimal extraction conditions were determined through single factor and response surface optimization experiments as follows: ultrasound temperature of 70 °C, extraction time of 25 min, ultrasonic power of 400 W and solvent-to-solid ratio of 2 mL/g, the experimental value of the ferritin yield was 32.18 ± 0.12 g/kg. Compared with traditional methods, Ultrasound-assisted extraction improved the ferritin yield and enhanced its structural stability. Bioinformatics analysis revealed that BLFer is a hydrophilic protein with strong thermal stability. The BLFer has a ferrous oxidase active center, which plays an important role in the oxidative precipitation and reductive release of iron. It can dissociate under strong acids or bases but maintains good stability after heat treatment. These findings will help improve the comprehensive utilization of animal by-products, and promote the potential application of animal by-product ferritin in food and other industries.