Amylolytic enzymes are currently investigated to improve industrial processes of starch degradation. Saccharomyces diastaticus 2047 isolated from cassava waste showed amylase and glucoamylase production, using starch ...Amylolytic enzymes are currently investigated to improve industrial processes of starch degradation. Saccharomyces diastaticus 2047 isolated from cassava waste showed amylase and glucoamylase production, using starch medium, and the highest rate was obtained in the initial growth phase, after incubation for 24 h at pH 5.5. Maximum amylase and glucoamylase activities （483.62 U mg^-1 protein and 290.85 U mg^-1 protein） were obtained at pH 5.5. The isolated enzymes exhibited thermostable properties as indicated by retention of 100% of residual activity at 55 ℃ for 45 min with total inhibition at 100 ℃. Extracellular enzyme from S diastaticus 2047 was partially purified by fractionated precipitation with ammonium sulphate. After 40% saturation produced 2,197.00 and 1,192.83 U/mg protein, and yield was 40% with purification 4.54 and 4.1 fold, respectively. This study presents feasibility on ethanol production from cassava pulps pretreated with diluted sulfuric acid by simultaneous saccharification and fermentation （SSF） with S. diastaticus 2047. The results indicated that the culture was able to produce ethanol with high yield without amylolytic enzyme adding by using cassava pulps pretreated with distilled water at 135 ℃ under pressure of 15 lb/inch^2 to produce ethanol yield as high as the cassava pulps pretreated with diluted sulfuric acid under the same condition. This suggests that S diastaticus with enzyme produced has potential for industrial applications.展开更多
Starch ofavocado seeds can be used as an alternative source of starch because it contains 80.1% starch. Natural starch can be made into a modified starch, for example dextrin. Dextrin can be made by using acid or enzy...Starch ofavocado seeds can be used as an alternative source of starch because it contains 80.1% starch. Natural starch can be made into a modified starch, for example dextrin. Dextrin can be made by using acid or enzyme hydrolysis. The purposes of this research were determine the concentration of hydrochloric acid （HCl）, the temperature and heating timein the optimum process of hydrolysis of starch into dextrin and to determine the quality of the resulting product dextrin terms of Indonesian National Standard 01-2593-1992. The methode was used in this research is hydrolisis with hydrochloric acid （HCl）. The results processing into starch avocado seed yield is 23.15%. HCl concentration, temperature and heating time significantly affect the value of dextrose equivalent （DE）, viscosity and part soluble in cold water. There is interaction between HCl concentration, temperature and heating time on the value of DE, viscosity and part soluble in cold water. Optimum conditions of process was obtained at a concentration of 0.15 N HCl, 30 minutes heating time and heating temperature of 90 ℃. Dextrose equivalent （DE） value is 19.61%. The value of solubility in cold water is 90.19%. Viscosity value is 1.61 ° E. Dextrin is not accordance with the standards of quality parameters Indonesian National Standard 01-2593-1992. Dextrin produced should be applied to non-food industry.展开更多
文摘Amylolytic enzymes are currently investigated to improve industrial processes of starch degradation. Saccharomyces diastaticus 2047 isolated from cassava waste showed amylase and glucoamylase production, using starch medium, and the highest rate was obtained in the initial growth phase, after incubation for 24 h at pH 5.5. Maximum amylase and glucoamylase activities （483.62 U mg^-1 protein and 290.85 U mg^-1 protein） were obtained at pH 5.5. The isolated enzymes exhibited thermostable properties as indicated by retention of 100% of residual activity at 55 ℃ for 45 min with total inhibition at 100 ℃. Extracellular enzyme from S diastaticus 2047 was partially purified by fractionated precipitation with ammonium sulphate. After 40% saturation produced 2,197.00 and 1,192.83 U/mg protein, and yield was 40% with purification 4.54 and 4.1 fold, respectively. This study presents feasibility on ethanol production from cassava pulps pretreated with diluted sulfuric acid by simultaneous saccharification and fermentation （SSF） with S. diastaticus 2047. The results indicated that the culture was able to produce ethanol with high yield without amylolytic enzyme adding by using cassava pulps pretreated with distilled water at 135 ℃ under pressure of 15 lb/inch^2 to produce ethanol yield as high as the cassava pulps pretreated with diluted sulfuric acid under the same condition. This suggests that S diastaticus with enzyme produced has potential for industrial applications.
文摘Starch ofavocado seeds can be used as an alternative source of starch because it contains 80.1% starch. Natural starch can be made into a modified starch, for example dextrin. Dextrin can be made by using acid or enzyme hydrolysis. The purposes of this research were determine the concentration of hydrochloric acid （HCl）, the temperature and heating timein the optimum process of hydrolysis of starch into dextrin and to determine the quality of the resulting product dextrin terms of Indonesian National Standard 01-2593-1992. The methode was used in this research is hydrolisis with hydrochloric acid （HCl）. The results processing into starch avocado seed yield is 23.15%. HCl concentration, temperature and heating time significantly affect the value of dextrose equivalent （DE）, viscosity and part soluble in cold water. There is interaction between HCl concentration, temperature and heating time on the value of DE, viscosity and part soluble in cold water. Optimum conditions of process was obtained at a concentration of 0.15 N HCl, 30 minutes heating time and heating temperature of 90 ℃. Dextrose equivalent （DE） value is 19.61%. The value of solubility in cold water is 90.19%. Viscosity value is 1.61 ° E. Dextrin is not accordance with the standards of quality parameters Indonesian National Standard 01-2593-1992. Dextrin produced should be applied to non-food industry.
