Effect of extraction methods on the properties of tilapia scale gelatins.

Three types of tilapia scale gelatins (hot water-pretreated gelatin, HWG; acetic acid-pretreated gelatin, AAG; and pepsin enzyme-pretreated gelatin, PEG) were extracted and their gel strength, foaming properties, and emulsifying properties were analyzed. They had different gel strength values: AAG (370 ± 10 g Bloom) > HWG (320 ± 10 g Bloom) > PEG (280 ± 10 g Bloom). The creaming index values of tilapia scale gelatin-stabilized fish oil-loaded emulsions were dependent on gelatin type (HWG ≈ AAG > PEG) at low gelatin concentration (2 mg/mL), whereas they were similar and low (8–10 %) at high gelatin concentration (10 mg/mL). Extraction methods had no consistently significant effects on the gelatin foaming properties. In summary, tilapia scale gelatins had better gel strength and foaming properties and similar or even better emulsifying properties than mammalian gelatins. Therefore, tilapia scales could be a potential source of gelatins to replace mammalian gelatins. • Tilapia scale gelatins were extracted using three different pretreatment methods. • Hot water- and pepsin-pretreated gels were the finest and coarsest, respectively. • These gelatins had better or comparable gel strength than commercial mammalian ones. • These gelatins had better foaming properties than some reported mammalian ones. • These gelatins had comparable emulsifying properties to some reported mammalian ones. [ABSTRACT FROM AUTHOR]