Screening of winery and olive mill wastes for lignocellulolytic enzyme production from Aspergillus species by solid-state fermentation

Wastes from olive oil and wine industries (as exhausted grape marc, vineshoot trimmings, two-phase olive mill waste, vinasses, and olive mill wastewater) were evaluated for lignocellulolytic enzyme production (as endocellulases, endoxylanases, and feruloyl esterases) by solid-state fermentation (SSF) with Aspergillus niger, Aspergillus ibericus, and Aspergillus uvarum. To study the effect of different solid medium composition and time in enzyme production, a PlackettBurman experimental design was used. Variables that had a higher positive effect in lignocellulolytic enzyme production were urea, time, and exhausted grape marc. The maximum values of enzymatic activity per unit of substrate dry mass were found with A. niger for feruloyl esterase. Enzymatic extracts from SSF with A. niger achieved maximum feruloyl esterase activity (89.53 U/g) and endoxylanase activity (3.06 U/g) and with A. uvarum for endocellulase activity (6.77 U/g). The enzyme cocktails obtained in the SSF extracts may have applications in biorefinery industries.Jose Manuel Salgado is grateful for the postdoctoral fellowship (EX-2010-0402) of the Education Ministry of Spanish Government. Luis Abrunhosa was supported by the grant SFRH/BPD/43922/2008 from Fundacao para a Ciencia e Tecnologia-FCT, Portugal

Antioxidant activity and polyphenol content in milling fractions of purple wheat

The aim of this study was to evaluate the antioxidant activity of four milling fractions of purple wheat breeding lines grown in 2010. Radical scavenging activity by the DPPH assay and reducing power of the samples were determined, as well as the content of polyphenols, flavonoids and anthocyanins. The obtained results showed that flour fractions (break and reduction flour) had lower total antioxidant potential than bran fractions (fine and coarse bran). A significant correlation was obtained between the DPPH and reducing power assay (R2 = 0.87). The correlation between antioxidant assays and polyphenol, flavonoid and anthocyanin content suggested that polyphenols in cereals are responsible for the antioxidant activities