Consulta: subjectFacets:"Assay"
Registros recuperados: 2
Data/hora: 05/06/2024 10:37:10

A comparison of methods to determine tannin acyl hydrolase activity
Provedor de dados: 52
Autores: Aguilar,Cristóbal; Christopher,Augur; Viniegra-González,Gustavo; Favela,Ernesto.
Six methods to determine the activity of tannase produced by Aspergillus niger Aa-20 on polyurethane foam by solid state fermentation, which included two titrimetric techniques, three spectrophotometric methods and one HPLC assay were tested and compared. All methods assayed enabled the measurement of extracellular tannase activity. However, only five were useful to evaluate intracellular tannase activity. Studies on the effect of pH on tannase extraction demonstrated that tannase activity was considerably under-estimated when its extraction was carried out at pH values below 5.5 and above 6.0. Results showed that the HPLC technique and the modified Bajpai and Patil methods presented several advantages in comparison to the other methods tested.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Tannin acyl hydrolase; Assay; Polyurethane foam; Solid state fermentation; Tannase.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89131999000300014

Evaluation of foam properties of saponin from Ilex paraguariensis A. St. Hil. (Aquifoliaceae) fruits
Provedor de dados: 60
Autores: Canto,Gizele Scotti do; Treter,Janine; Yang,Samanta; Borré,Gustavo Luís; Peixoto,Maria Paula Garofo; Ortega,George González.
Saponins are natural compounds able to form abundant foam, a desirable quality required in some chemical, foods, cosmetic and pharmaceutical processes. Ilex paraguariensis A. St. Hil. (Aquifoliaceae) known as mate, is a South American widely cultivated specie due to the preparation of a tea-like beverage from its leaves. Moreover, its green fruits are a rich source of non-toxic and very low haemolytic saponins. In this study, mate saponin fraction (MSF) was evaluated as a foam former, focusing on its foamability, foam lifetime, and film drainage in the presence of different electrolytes (ionic strength I = 0.024 M). Sodium dodecyl sulphate (SDS) and polysorbate 80 (Poly-80) were used as reference surfactants. The critical micelle concentration (CMC), the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ilex paraguariensis; Aquifoliaceae; Mate; Saponins; Surfactants; Foam; Assay.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502010000200010