Radiology

Organic chemistry

Yellowfin tuna

Proline

Extraction (chemistry)

Thermal stability

Biology

Sonication

Nuclear chemistry

Engineering

Solubility

Ultrasound

Fourier transform infrared spectroscopy

Chemistry

Acetic acid

Tuna

Hydroxyproline

Fishery

Fish <Actinopterygii>

Food science

Chemical engineering

Chromatography

Amino acid

Biochemistry

Medicine

Ultrasonics Sonochemistry

The effect of ultrasound treatment (300 W; 0, 5, 10, 15, 20 and 25 min) on the extractability of acid soluble collagen from yellowfin tuna skin and its structural, physicochemical and functional properties were investigated. Ultrasound treatments significantly increased collagen extraction yield from the tuna skin up to 2.7 times, compared to the conventional extraction with acetic acid. The level of proline, hydroxyproline and thermal stability of collagens increased by applying ultrasound while their native triple-stranded helical structure was well-preserved, as revealed by X-ray diffraction and FTIR spectroscopy. However, ultrasound treatment reduced the particle size of the collagens which increased their pH and salt induced solubility. The water holding capacity and the emulsifying properties of ultrasound treated collagens were also higher than those produced with the conventional method. Altogether, the results suggested that ultrasonication can be a promising assistant technology for improving native collagen extraction efficiency from tuna skin and its functionality but its duration should be carefully optimized.

Impact of ultrasound on extractability of native collagen from tuna by-product and its ultrastructure and physicochemical attributes