Abstract:

Gelatin was extracted from silver carp (Hypophthalmichthys molitrix) skin, and the physical and chemical
characteristics of gelatin extracted at different temperatures (30, 50, 70, 90 and 100 ℃) were compared. The maximum
ultraviolet absorption peaks of all gelatin appeared near 218 nm. The maximum gelatin recovery ((86.91 ± 0.98) %) was
obtained when extraction was performed at 90 ℃, while the maximum gel strength ((896.75 ± 117.03) g) was obtained when
the extraction temperature was 50 ℃. The SDS-PAGE pattern indicated that gelatin extracted at 30 and 50 ℃ contained
α1, α2 and β chains, while that extracted at 70, 90 and 100 ℃ did not have obvious bands, which was presumably ascribed
to heat degradation of gelatin. The thermal denaturation temperatures of the gelatin extracted at 30, 50, 70, 90 and 100 ℃
were (97.88 ± 2.65), (108.66 ± 0.43), (106.48 ± 3.33), (100.27 ± 2.37) and (99.56 ± 0.37) ℃, respectively. The higher the
extraction temperature was, the smaller the values of G’ and G’’ were, and the worse rheological properties of gelatin were.

Key words: extraction temperature, gelatin, recovery, gel strength, rheological properties