Germinating seeds of Tamarindus indica contain endo-β-1, 4-xyloglucanases which degrade tamarind xyloglucan, but not carboxymethylcellulose (CMC). The xyloglucanases are isolated from the germinating tamarind seeds u...Germinating seeds of Tamarindus indica contain endo-β-1, 4-xyloglucanases which degrade tamarind xyloglucan, but not carboxymethylcellulose (CMC). The xyloglucanases are isolated from the germinating tamarind seeds using 50 mM acetate buffer, pH 5.5 containing 0.5 M NaCl. The Km value is 0.667 g/liter and the enzyme is optimally active at pH 5.5 and stable between pH 4 - 6.5. The optimum temperature is 45?C and is quite stable upto 50?C. The activity declined by 50% at 60?C and is completely inactivated at 70?C. Highest xyloglucanase activity and specific activity are observed on the 23rd day of germination. The polyacrylamide gel electrophoresis (PAGE) indicated the presence of five isozymes of xyloglucanases which are visualized by activity staining separately with congo red and grams iodine. Isozyme 2 is the major xyloglucanase present throughout the germination period.展开更多
A traditional process used by farmers in Chad consists in soaking slices of taro (Colocasia esculenta L. SCHOTT) in tamarind infusion, or in corn solution or in water over a 24-hour period to reduce the acridity of ta...A traditional process used by farmers in Chad consists in soaking slices of taro (Colocasia esculenta L. SCHOTT) in tamarind infusion, or in corn solution or in water over a 24-hour period to reduce the acridity of taro and facilitate cooking. The aim of this study was to assess the effect of traditional soaking on the in vitro digestibility of taro flour using or not using an α-amylase enzyme. The digestion without the enzyme has shown that the soaking processes improve the digestibility of taro flour (from 39.30% for the control sample to 75.11% (after tamarind infusion) and 78.67% (treatment with water) after 24 hours of soaking). Soaking over a 6-hour period and preferentially in tamarind infusion or in corn solution obtains highly digestible flour (around 95% of digestibility rate after 3 hours of enzymatic digestion).展开更多
文摘Germinating seeds of Tamarindus indica contain endo-β-1, 4-xyloglucanases which degrade tamarind xyloglucan, but not carboxymethylcellulose (CMC). The xyloglucanases are isolated from the germinating tamarind seeds using 50 mM acetate buffer, pH 5.5 containing 0.5 M NaCl. The Km value is 0.667 g/liter and the enzyme is optimally active at pH 5.5 and stable between pH 4 - 6.5. The optimum temperature is 45?C and is quite stable upto 50?C. The activity declined by 50% at 60?C and is completely inactivated at 70?C. Highest xyloglucanase activity and specific activity are observed on the 23rd day of germination. The polyacrylamide gel electrophoresis (PAGE) indicated the presence of five isozymes of xyloglucanases which are visualized by activity staining separately with congo red and grams iodine. Isozyme 2 is the major xyloglucanase present throughout the germination period.
基金grateful to Chad French Ambassy for the financing of this project.
文摘A traditional process used by farmers in Chad consists in soaking slices of taro (Colocasia esculenta L. SCHOTT) in tamarind infusion, or in corn solution or in water over a 24-hour period to reduce the acridity of taro and facilitate cooking. The aim of this study was to assess the effect of traditional soaking on the in vitro digestibility of taro flour using or not using an α-amylase enzyme. The digestion without the enzyme has shown that the soaking processes improve the digestibility of taro flour (from 39.30% for the control sample to 75.11% (after tamarind infusion) and 78.67% (treatment with water) after 24 hours of soaking). Soaking over a 6-hour period and preferentially in tamarind infusion or in corn solution obtains highly digestible flour (around 95% of digestibility rate after 3 hours of enzymatic digestion).
