Valorization of brewers' spent grain and spent yeast through protein hydrolysates with antioxidant properties

• Tipo: Artigo em Revista Científica Internacional
• Data: 2016

Autores

Vieira, E (Autor) Outra; Teixeira, J (Autor) Outra; Ferreira, Isabel (Autor) FFUP

Revista

Título: European Food Research and Technology

Vol. 242

Páginas: 1975-1984

ISSN: 1438-2377

Editora: Springer Nature

Indexação

ISI Web of Knowledge - 3 Citações

Scopus - 0 Citações

Outras Informações

ID Authenticus: P-00K-F05

DOI: 10.1007/s00217-016-2696-y

Abstract (EN): Brewers' spent grain (BSG) and spent yeast (BSY) are the main by-products of the brewing industry, with currently limited valuable applications. However, BSG protein fraction can be a valuable substrate for enzymatic hydrolysis to produce hydrolysates with biological properties and BSY contains numerous vacuole proteases, which can be used to obtain these hydrolysates. Thus, the objective of this work was to explore the valorization of these two brewing by-products, based on the production of BSG protein hydrolysates that present antioxidant properties. Response surface methodology was employed to optimize the hydrolysis of BSG proteins using BSY proteases, based on degree of hydrolysis (DH %), total phenolic content (TPC) and antioxidant activity (FRAP assay). Reversedphase chromatography was also used to monitor the hydrolysis rate (HR %), and the potential presence of endogenous and other inhibitors of BSY proteases was also investigated. BSG protein hydrolysate prepared at 50 degrees C, pH 6, for 6 h and using an enzyme/substrate ratio of 0.29:1 U/mg presented maximum bioactivity with DH % of 17.10 %, TPC of 1.65 mg GAE/mL and FRAP value of 1.88 mg Trolox equivalent/mL. A good correlation was obtained between HR (%) and DH (%) (R-2 = 0.928). The experimental values agreed with the predicted values (p < 0.05), suggesting a good fit between the models and the experimental data. BSY proteases involved in the hydrolysis of BSG proteins are serine peptidases and metallopeptidases.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10