Production of oligosaccharides using industrial amylases | |
| Author | Alamgir, Md. |
| Call Number | AIT Thesis no.BP-00-01 |
| Subject(s) | Oligosaccharides Amylases |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. BP-00-01 |
| Abstract | Starch is an important commodity, that is used at a large scale for the production of fructose, glucose and the oligosaccharides maltose and maltodextrins. In this study industrial amylases Termamyl and Promozyme have been applied in the partial hydrolysis of starch for the production of specific oligosaccharides. Various types of starches were partially hydrolyzed for the production of oligosaccharides with Termamyl and different combinations of Termamyl and Promozyme. These studies were carried out at 55 °C with different incubation periods. The physico-chemical properties of different starches were studied by viscometry and the oligosaccharide profiles of the hydrolysate after enzymatic hydrolysis were analyzed by chemical analysis and high performance liquid chromatography (HPLC). Cassava corn mung bean and sago starch produced nearly the same hydrolytic pattern after partial hydrolysis with Termamyl only and by Termamyl followed by Promozyme. RVA analysis of these starches showed that sago had the lowest pasting temperature (50 °C) and corn the highest (78 °C). The other varieties: taro. sweet potato, wheat and rice produced different hydrolytic patterns. Partial hydrolysis of starch with Termayl followed by Promozyme produces higher amount of oligosaccharides compared to Termamyl alone. The composition of the hydrolysate is slightly different. But in both the cases, the altodextrin G (maltopentaose) is produced in highest amount compared to the formation of other oligosaccharides. On the other hand simultaneous treatment of Termamyl and Promozyme did not result in more oligosaccharides compared to Termamyl followed by Promozyme. It was found that starch treated with 2 h Termamyl followed by 10 h Promozyme with Termamyl leads to the highest amount of oligosaccharides. During enzymatic hydrolysis by followed by Promozyme, starch molecules are converted into a ixture of maltodextrins with a various degree of polymerization of 1-5 (G1-G5) and small amount of higher oligosaccharides. Yeast (Succharomyces cerevisiae) cells in the stationary growth phase were added to the hydrolysate to consume preferentially the lower oligosaccharides. Under the conditions used, the hydrolysate is the only source of carbon that is available by the yeast cells for their survival. Different periods of incubation and different amounts of yeast cells were added to the starch hydrolysate to study the selective consumption of the various maltodextrins by the yeast. It was found that after 1 h of incubation, yeast cells consumed all the G1 and G3 are also consumed within 12 h of incubation with an adequate amount of yeast cells. Enzyme treatment combined with stationary phase yeast fermentation, leads to the formation of oligosaccharides that mainly contain G5 and small amount of G4. Different chromatographic techniques, charcoal column, gel permeation chromatography and thin layer chromatography were applied to separate the G4 and G5 oligosaccharides after yeast consumption. Charcoal column chromatography did not lead to separation. The results with GPC and TLC suggest that these techniques can be used to separate the oligosaccharides according to their molecular weight. |
| Year | 2000 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. BP-00-01 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Bioprocess Technology (BP) |
| Chairperson(s) | Willem F. Stevens; |
| Examination Committee(s) | Suwalee Chandrkrachang;Sudip K. Rakshit;Pakorn Nuchnoi; |
| Scholarship Donor(s) | Deutscher Akademischer Austausch Dienst (DAAD Germany); |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology |