RESUMO
BACKGROUND: Fish skin has become a new source of collagen. It is usually extracted at low temperature. Increasing the extraction temperature can increase the collagen yield. However, high temperature might cause degradation of the triple helical structure of collagen, which is related to its functional biomaterial. This work thus aimed to investigate the effect of extraction temperature on the extraction efficiency and characteristics of acid-soluble collagen (ASC), particularly its triple helical structure. RESULTS: ASC was extracted at 5 ± 1, 15 ± 1 and 25 ± 1 °C for 0-24 h with 0.3 or 0.5 mol L(-1) acetic acid. The results showed that extraction with 0.5 mol L(-1) acetic acid gave a higher extraction efficiency than that in 0.3 mol L(-1) acetic acid (P < 0.5). Extraction at 25 ± 1 °C for 5 h with 0.5 mol L(-1) acetic acid gave a higher extraction efficiency (73.73 ± 1.28%), which is higher than that of 5 ± 1 °C by about 1.7-fold. All ASC obtained were identified as type I collagen and showed similar physicochemical properties. CONCLUSION: The results showed that extraction temperature strongly affected extraction efficiency. Extraction at 25 °C did not affect the triple helical structure, which was confirmed by the results of Fourier transform infrared, circular dichroism spectrum and collagen self-assembly. © 2015 Society of Chemical Industry.
Assuntos
Ciclídeos , Colágeno Tipo I/química , Proteínas de Peixes/química , Resíduos Industriais/análise , Pele/química , Ácido Acético/química , Animais , Dicroísmo Circular , Temperatura Baixa , Colágeno Tipo I/economia , Colágeno Tipo I/isolamento & purificação , Eletroforese em Gel de Poliacrilamida , Proteínas de Peixes/economia , Proteínas de Peixes/isolamento & purificação , Indústria de Processamento de Alimentos/economia , Hidroxiprolina/análise , Indicadores e Reagentes/química , Resíduos Industriais/economia , Cinética , Microscopia Eletrônica de Varredura , Desnaturação Proteica , Dobramento de Proteína , Estabilidade Proteica , Estrutura Secundária de Proteína , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , TailândiaRESUMO
BACKGROUND: Sea cucumber (Stichopus vastus) is considered an underutilized resource, since only its stomach and intestines are eaten raw as salad in a few countries and the remaining parts, especially the integument rich in collagen, is discarded. Hence a valuable by-product having potential nutraceutical and pharmaceutical applications is wasted. In the present investigation, pepsin-solubilized collagen (PSC) from the integument of S. vastus was isolated, purified and characterized. RESULTS: Sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis showed that the purified collagen was of type I, consisting of three α1 chains of approximately 122 kDa each. The peptide map of PSC digested by V8 protease was different from that of calf skin type I collagen. Fourier transform infrared spectroscopy revealed that the triple helical structure was well preserved in isolated collagen. The denaturation temperature of PSC was 21.23 °C and showed good gel-forming capability at pH 6.5 and 300 mmol L⻹ NaCl. CONCLUSION: It is inferred that the collagen isolated from S. vastus integument has potential for use as an alternative to land-based mammalian collagen in food, nutraceuticals and pharmaceutical industries.
