Abstract The objective of the present study was to develop a cost-effective medium, using agro-industrial wastes for the production of a polygalacturonase by Wickerhanomyces anomalus of interest in cassava starch industries. The effect of several raw agro-industrial wastes and others nutrients on polygalacturonase production by W. anomalus, were evaluated, in a reference fermentation medium, using statistical designs, by batch culture. The ability of the cell-free supernatant to extract cassava starch was evaluated. Lemon peel was the best inducer for the production of PGase. Statistical analysis of the data showed that lemon peel, Mg+2 and PO4HK2 had significant effect on PGase production, and the others variables (yeast extract, Ca+2, Fe+2, amino acid and trace element solution) were no significant. PGase synthesis reached ~31 EUmL-1, in the OFM (glucose, lemon peel, urea, vitamins, KH2PO4 and MgSO4), after 12 h of culture, at a lab scale bioreactor. PGase of W. anomalus, was able to disintegrate cassava tuber tissue, and the starch granules contained within the cells were released into the reaction medium. Lemon peel can be used as inducer for PGase production by W. anomalus, in a low cost culture medium, appropriate for the production of the enzyme at large scale.

Abstract Tetragonisca fiebrigi, is a bee of the subfamily Meliponidae traditionally known as Yateí. Its honey differs from the honey produced by Apis mellifera because it is less viscous, more acidic, has sweetness and particular aromas. It is important to know the behavior of yatei honey in different storage conditions, in order to preserve the characteristics of the honey and ensure the product as harmless. The objective was to determine the influence of temperature, packaging type and storage time of Yateí honey on antimicrobial properties, microbial (Total Mesophilic Aerobic and Mold and Yeast Count) and physicochemical parameters (pH, hydroxymethylfurfural (HMF), acidity, moisture content and diastase), with methodology of national and international standards. The antimicrobial effect was variable against strains of the genus Staphylococcus aureus. The most significant microbiological quality levels were Mold and Yeast counts (> 102 CFU / g). The physicochemical parameters with the most significant values were acidity (to: 42.5 meq acid/kg honey), moisture content (to: 26%) and HMF (to: 3.8mg/kg honey). Storage at refrigeration temperature maintained standard values close to Apis mellifera honey during 180 days; whereas at room temperature it was better to maintain antimicrobial power. No significant difference was found between plastic storage containers vs. glass.

Extratos de erva-mate têm a sua capacidade antioxidante in vitro atribuída à presença de compostos polifenólicos, principalmente ácidos clorogênicos e derivados do ácido dicafeoilquínico. Embora DPPH seja um dos ensaios mais utilizados para avaliar a capacidade antioxidante dos compostos puros e extratos de plantas, o fato de que há uma padronização pobre na sua aplicação torna as comparações entre os diferentes extratos muito difíceis. Visando conseguir uma técnica padronizada para medir a capacidade antioxidante de extratos de erva-mate, propomos o seguinte procedimento: 100 µL de uma diluição do extrato aquoso são misturados em duplicata, com 3,0 mL de uma solução de trabalho de DPPH em metanol absoluto (100 µM.L-1), com um tempo de incubação de 120 minutos no escuro a 37 ± 1 °C e, em seguida, a absorbância é lida a 517 nm contra o metanol absoluto. Os resultados devem ser expressos em equivalentes de ácido ascórbico ou de equivalentes de Trolox em percentagem de massa (g% de matéria seca), a fim de facilitar as comparações.

Yerba maté extracts have in vitro antioxidant capacity attributed to the presence of polyphenolic compounds, mainly chlorogenic acids and dicaffeoylquinic acid derivatives. DPPH is one of the most used assays to measure the antioxidant capacity of pure compounds and plant extracts. It is difficult to compare the results between studies because this assay is applied in too many different conditions by the different research groups. Thus, in order to assess the antioxidant capacity of yerba maté extracts, the following procedure is proposed: 100 µL of an aqueous dilution of the extracts is mixed in duplicate with 3.0 mL of a DPPH 'work solution in absolute methanol (100 µM.L-1), with an incubation time of 120 minutes in darkness at 37 ± 1 °C, and then absorbance is read at 517 nm against absolute methanol. The results should be expressed as ascorbic acid equivalents or Trolox equivalents in mass percentage (g% dm, dry matter) in order to facilitate comparisons. The AOC of the ethanolic extracts ranged between 12.8 and 23.1 g TE % dm and from 9.1 to 16.4 g AAE % dm. The AOC determined by the DPPH assay proposed in the present study can be related to the total polyphenolic content determined by the Folin-Ciocalteu assay.