Ultrasound-assisted extraction of collagen from clown featherback (Chitala ornata) skin: Yield and molecular characteristics.

BACKGROUND Clown featherback (Chitala ornata) skin, a by-product from filleting process line, could serve as a good aquatic collagenous source. Nevertheless, the typical collagen extraction method, that was a time-consuming process provided relatively low yield. The ultrasound had been reported as alternative technique on enhancing of the extraction efficiency of several compounds but the harsh condition of ultrasound could affect their physicochemical and molecular characteristics. Thus, the application of ultrasonication under appropriate condition could be a promising means to improve the extraction efficiency of collagen from Clown featherback skin. RESULTS Ultrasonication with different amplitudes (20-80%) and times (10-30 min) were implemented during extraction. Ultrasound-assisted process (UAP) could increase the yield of collagen (P ˂ 0.05), while UAP could also cause the collagen purity decrease evaluated by hydroxyproline content. There was no change on the solubility of resulting collagens dramatically. UAP induced protein degradation, particularly with increasing amplitude and time, where slight changes in pI value of collagen were observed. UAP had no adverse effect on molecular structure, where triple helical structure was still retained, when 80% amplitude for 10 min (UAP-80/10-C) was employed. Amino acid composition of UAP-80/10-C reconfirmed the unique characteristic of collagen with imino acid containing. CONCLUSION UAP with appropriate condition could be used to improve the extraction yield with minimal effects on molecular integrity of resulting collagen. In addition, fish skin waste from cutting process line, particularly Clown featherback skin, could be maximized exploited as a value-added product, fish skin collagen. This article is protected by copyright. All rights reserved.