Extraction and characterization of collagen from sheep slaughter by-products.

There is a growing search for alternative raw materials to obtain collagen and hydrolysates and processes that do not threaten the environment or human health. Thus, sheep slaughter residue, which doesn't yet have an adequate and sustainable destination, is an excellent source of study. The objective of this study was to investigate the technological properties of collagen extracted from sheep slaughter by-products. It was possible to produce and characterize collagens extracted from sheep slaughter by-products. The yield of collagen was 18.0% and 12.5% for lamb and sheep by-products, respectively, on a dry basis. Lamb and sheep collagens showed similar FTIR and digestibility spectra and increased solubility at acidic pH-value. Higher foaming capacity was found for lamb collagen, while the sheep collagen presented higher viscosity. The emulsifying power of the collagens was 59.1 and 69.6 m2/g for lamb and sheep by-products, respectively. The collagens presented bands corresponding to α1, α2, and ß chains, characteristic of collagen type I and a molecular weight (SDS-PAGE) between 100 and 5 kDa. The collagens of this study showed potential for application in food products, both for the technological improvement and nutrient enrichment, adding value and giving a sustainable destination to sheep slaughter by-products.

Enzymatic hydrolysis (pepsin) assisted by ultrasound in the functional Properties of hydrolyzates from different collagens / Hidrólise enzimática (pepsina) assistida por ultrassom nas propriedades Funcionais de hidrolisados de diferentes colágenos

ABSTRACT: Enzymatic hydrolysis (pepsin) assisted with or without ultrasound in the functional properties of hydrolyzates from different collagens were analyzed. Degree of hydrolysis, antioxidant activity (DPPH) and antimicrobial activity (MIC) were assessed. The treatment that resulted in greater antioxidant activity for the fiber sample was with the use of 4% of enzyme and concomitant ultrasound (40.7%), leading to a degree of hydrolysis of 21.7%. For the powdered fiber sample the hydrolysis treatment with use of 4% of enzyme resulted in lower protein content (6.97mg/mL), higher degree of hydrolysis (19.9%) and greater antioxidant activity (38.6%). The hydrolyzates showed inhibitory capacity against gram-negative bacteria Salmonella choleraesuis and gram-positive bacteria Staphylococcus aureus. It can be concluded that enzymatic hydrolysis concomitant or not with the use of ultrasound increased the functionality of the fiber and powdered fiber samples, for the other samples its use as supplementary treatment was not productive, due to the worse results of antioxidant activity (DPPH) reported. However, it provided greater hydrolysis degree.

RESUMO: Foram avaliados os efeitos da hidrólise enzimática (pepsina) assistida com ou sem ultrassom nas propriedades funcionais de hidrolisados de diferentes colágenos. Foi analisado o grau de hidrólise, a atividade antioxidante (DPPH) e a atividade antimicrobiana (MIC). O tratamento que possibilitou maior atividade antioxidante para a amostra fibra foi com a utilização de 4% de enzima e ultrassom concomitante (40,7%), levando a um grau de hidrólise de 21,7%. Para a amostra fibra pó o tratamento de hidrólise com uso de 4% de enzima resultou em menor teor de proteína (6,97mg/mL), maior grau de hidrólise (19,9%) e maior atividade antioxidante (38,6%). Os hidrolisados mostraram capacidade inibitória contra a bactéria gram-negativa Salmonella choleraesuis e gram-positiva Staphylococcus aureus. Pode-se concluir que a hidrólise enzimática concomitante, ou não, ao uso do ultrassom apresentou aumento da funcionalidade das amostras fibra e fibra pó. Para as demais amostras, sua utilização como tratamento complementar, a hidrólise não foi interessante, devido aos piores resultados de atividade antioxidante (DPPH) encontrados. Porém, proporcionou maior grau de hidrólise.