Biochemical characterisation and assessment of fibril-forming ability of collagens extracted from Bester sturgeon Huso huso×Acipenser ruthenus

•High yields of type I collagen were obtained from skin and swim bladder of sturgeon.•High yield of type II collagen was obtained from the notochord.•These collagens showed high thermal stabilities (>26°C) suitable for industrial use.•Sturgeon type-I collagens showed better fibril-forming ability than porcine collagen.•Sturgeon type-I collagens formed thicker fibrils than porcine collagen. Collagens purified from Bester sturgeon organs were characterised biochemically, and their fibril-forming abilities and fibril morphologies formed in vitro clarified. Yields of collagens were 2.1%, 11.9%, 0.4%, 18.1%, 0.4%, 0.8% and 0.03% (collagen dry weight/tissue wet weight) from scales, skin, muscle, swim bladder, digestive tract, notochord and snout cartilage, respectively. Using SDS–PAGE and amino acid composition analyses, collagens from scales, skin, muscle, the swim bladder and digestive tract were characterised as type I, and collagens from the notochord and snout cartilage as type II. Denaturation temperatures of the collagens, measured using circular dichroism, were 29.6, 26.8, 29.0, 32.9, 31.6 and 36.3°C in scales, skin, muscle, swim bladder, digestive tract, and notochord, respectively. For fibril formation, swim bladder and skin collagen showed a more rapid rate of increase in turbidity, a shorter time to attain the maximum turbidity, and formed thicker fibrils compared with porcine tendon type I collagen.