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

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 investi-gated. 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 tech-nology for improving native collagen extraction efficiency from tuna skin and its functionality but its duration should be carefully optimized.

Automated summary

The effect of ultrasound treatment on the extractability and properties of collagen from yellowfin tuna skin was investigated. Ultrasound treatment significantly increased collagen extraction yield and improved its structural and functional properties. However, it also caused a reduction in particle size and an increase in solubility. Overall, ultrasonication can be a promising technique for enhancing collagen extraction efficiency and functionality, but the duration of treatment needs to be optimized.