Production of Collagens and Protein Hydrolysates with Antimicrobial and Antioxidant Activity from Sheep Slaughter By-Products.

This work aimed to produce collagens and hydrolysates with antimicrobial and antioxidant activity from sheep slaughter by-products. The by-products (sheep and lamb) were treated and extracted. The collagens were hydrolyzed with the enzyme Alcalase®. The spectra of collagens and hydrolysates were similar (amide bands I, II, III, A, B). The bands presented by the collagens (α1, α2, ß) were characteristic of type I collagen. The hydrolysates showed molecular weight peptides equal to/lower than 15 kDa. Collagens had a denaturation temperature of 39.32 (lamb) and 36.38 °C (sheep), whereas the hydrolysates did not undergo thermal transition. Hydrolysates showed lower values of antioxidant activity (AA) than the collagens. The collagens from lamb and from sheep displayed an AA of 13.4% (concentration of 0.0002%) and 13.1% (concentration of 0.0005%), respectively. At the concentration of 0.0020%, the lamb hydrolysates displayed an AA of 10.2%, whereas the sheep hydrolysates had an AA of only 1.98%. Collagen also showed higher antimicrobial activity compared to hydrolysates, requiring a lower concentration to inhibit the microorganisms tested. Sheep slaughter by-products proved to be a viable source for obtaining protein hydrolysates and collagens with antimicrobial and antioxidant activity, which can be applied in the development of nutraceuticals beneficial to human health.

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.

Efeitos da Adição de Fibra de Trigo na Cor e pH de Hambúrguer de Carne Bovina / Effects of Addition of Wheat Fiber on Color and pH of Hamburger

O desenvolvimento de hambúrguer adicionado de fibra de trigo é uma alternativa interessante de alimento com apelo funcional, pois este produto já faz parte da rotina alimentar da maioria dos brasileiros, em virtude de suas características sensoriais e facilidade de preparo. No entanto, o entendimento dos aspectos tecnológicos e a melhor forma de aplicar os ingredientes funcionais aos produtos cárneos são fundamentais para que estes não percam suas características. O objetivo deste estudo foi avaliar os efeitos da adição de fibra de trigo com diferentes granulometrias na cor e no pH de hambúrguer durante 75 dias de estocagem a -18 °C. Os resultados indicaram que a adição de fibra com diferentes granulometrias não afetou o pH, mas afetou a cor dos produtos (parâmetros L*, a* e b*). A mistura das fibras nas proporções testadas (4% ou 8%) afetou negativamente a cor dos produtos durante os 75 dias de estocagem a -18 °C. A fibra de menor granulometria (35 ?m de comprimento e 20 ?m de espessura), que foi testada até o nível de 4%, mostrou ser uma alternativa viável para o desenvolvimento de hambúrguer com apelo funcional. Os bons resultados obtidos por esta fibra podem ser explicados pela sua melhor distribuição e interação com a massa cárnea, minimizando os efeitos da mudança de cor que foram piores para a fibra de maior granulometria (250 ?m de comprimento e 25 ?m de espessura).

The development of beef burger with added wheat fiber is an interesting alternative with functional appeal because burgers are part of the routine diet of most Brazilians due to its sensory characteristics and ease of preparation. However, understanding the technological aspects and the best method to apply functional ingredients to meat products are essential so that the products do not lose their characteristics. The objective of this study was to evaluate the effects of addition of wheat fiber with different particle sizes on color and pH of hamburger during 75 days of storage at -18 °C. The results indicated that the addition of wheat fiber with different particle sizes into beef burgers did not influence the pH but affected the color of the products (L*, a* and b* parameters). The mixture of fibers in the proportions tested (4% or 8%) negatively affected the color of the product during the 75 days at -18 °C. The dietary fiber presenting smaller particle size (35 ?m length and 20 ?m thickness) that was tested until 4% level has shown to be a viable alternative for the development of a functional beef burger. The good results obtained for this fiber can be explained by its better distribution and interaction with the meat mixture, minimizing the effects of color change, which were worse for the products containing dietary fiber with larger particle (250 ?m length and 25 ?m thickness).

Observações Estruturais de Hambúrguer Adicionado de Fibra de Trigo com Diferentes Granulometrias / Structural Observations of Beef Burger containing Wheat Fiber of Different Sizes

The objective of the present study was to develop different formulations of functional beefburgers with addition of wheat fiber of different granule sizes, and to evaluate the effect of fibers on the structural and physical properties of the product. The fibers used were Fiber 200 (250 μm in length and 25 μm in thickness) and Fiber 600/30 (35 μm in length and 20 μm in thickness), and the addition followed a 2² central composite design. The fiber addition altered the physical and structural properties of the burgers. Significant differences were observed (p < 0.05) in the physical properties of the burgers due to both the variations in particle size of the wheat fiber, and the different concentrations. Comparing the observations found through microscopy with the results of shear force and cooking losses, it was concluded that there was a relationship between some properties and their respective microscopic structures. The best results were found for the treatment F2, indicating that the Fiber 200 (larger particles) allowed the maintenance of a texture close to the standard, F1 (without fiber addition), and lower cooking loss when compared to the product containing fiber of lower particle size (Fiber 600/30). The fiber mixtures in the proportions studied were not a viable alternative due to the increase in the hardness of the product.

Objetivou-se com o presente trabalho desenvolver diferentes formulações de hambúrguer funcional de carne bovina, com a adição de fibra de trigo com diferentes granulometrias e avaliar o efeito das fibras nas propriedades físicas e estruturais do produto. As fibras testadas foram denominadas de Fibra 200 (250 μm de comprimento e 25 μm de espessura) e Fibra 600/30 (35 μm de comprimento e 20 μm de espessura) e a adição seguiu um Delineamento Composto Central 2². A adição das fibras alterou as propriedades físicas e estruturais dos hambúrgueres desenvolvidos. Foram observadas diferenças significativas (p <0,05) nas propriedades físicas dos hambúrgueres, decorrentes da variação da granulometria da fibra de trigo e das concentrações testadas. Comparando as observações encontradas na microscopia com os resultados das avaliações de força de cisalhamento e perdas por cocção, conclui-se que existe relação entre algumas propriedades com as respectivas estruturas microscópicas. Os melhores resultados foram encontrados para F2, indicando que a Fibra 200 (maior granulometria) permitiu a manutenção da textura próxima do padrão F1 (sem fibra) e menores perdas por cocção, quando comparado com o produto adicionado da fibra de menor granulometria (Fibra 600/30). A mistura das fibras nas proporções testadas não se mostrou uma alternativa viável devido o aumento na dureza do produto.