Gastrointestinal delivery of collagen hydrolysates from codfish skins using chitosan-tpp hydrogels

• Autor(a) principal: Silva, Isa Soares da
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/39584
• topic: Collagen; Codfish skins; Marine biorefinery; Bioactive peptides; Hydrogels

Currently, approximately 70 % of the fishing industry's production is waste, including heads, skins, bones, and scales. However, despite being discarded, these by-products can be valued as new feedstocks for applications in various industries. Collagen is a protein present in various organisms and tissues with a wide range of applications. Most of the collagen used in industry is derived from mammals, but considering some health and religious restrictions, the use of marine collagen present in codfish skin has been proposed as a new alternative. Moreover, this protein was extracted with acetic acid (Yield of extraction: 26.7 %) and with a mixture of urea and propanoic acid (1:2) (Eutectic Solvent; Yield of extraction: 2.2 %). Additionally, recurring to enzymatic hydrolysis with alcalase, several bioactive collagen peptides with antioxidant and antihypertensive activities, were obtained in an ideal 120 minutes of hydrolysis. The hydrolysates were encapsulated in chitosan hydrogels with tripolyphosphate to maintain these activities throughout the gastrointestinal tract. At circa, 38.3% of the peptides extracted with acetic acid and 39.2% of those extracted with the eutectic solvent were successfully encapsulated. Finally, an in vitro gastrointestinal tract simulation was performed evaluating the release of peptides from the encapsulates and the effect of digestion on the hydrolysates. Thus, it was possible to observe that the peptides were mostly released in the intestine and that beads with acetic acid-based peptides released approximately 87 % of their content, while those extracted with the urea and propanoic acid mixture only had 58 %. It is noteworthy that the action of enzymes in the human tract did not significantly alter the collagen hydrolysates, but their bioactivities suffered alterations, so encapsulation is the most suitable alternative to apply these peptides as possible nutraceuticals to replace conventional drugs.