Improvement of the extraction efficiency of starch from sweet potato | |
| Author | Zhang, Kun |
| Call Number | AIT Thesis no. BP-98-4 |
| Subject(s) | Sweet potatoes Starch industry |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School ofEnvir01m1ent, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | A small sweet potato production and processing plant was observed on site in China, where 80% of the world sweet potato is produced. It was found that such small scale sweet potato starch processing plants have a low extraction efficiency which is about 30-50%. The improvement of sweet potato extraction efficiency is definitely necessary and could increase of the income of the farmers. Laboratory experiments were done to improve sweet potato starch extraction efficiency. The influencing factors including blending time, sedimentation time, filtration method, commerdal cellulase enzyme addition, and effect of Ca(OH)2 on starch extraction were studied. The results show that 1 min was the best blending time. Starch extraction efficiency decreased with the increase of blending time. Sedimentation time of 6 hours is recommended. Surface response methodology of experimental design to determine the best combination of pH, temperature and incubation time for the activity of inherent enzyme in the tubers was also applied to find the optimum starch extraction from sweet potato. The optimum condition got from the surface response method is temperature 55 °c, pH 5.4 and incubation time 6.2 hours. The starch extraction efficiency increased about 10% w1der the optimized conditions for the control. The conunercial cellulase product Cytolase Ml 02 and PCL5 from Gist-Brocades could increase the extraction efficiency by 20 - 30% with the dosage of 1.0 ml and 2.5 ml per kg fresh sweet potato tuber under the recommended reaction conditions respectively. Ca(OH)2 does show significant effect on sweet potato quality like whiteness but little improvement on extraction level. |
| Year | 1998 |
| 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) | Rakshit, Sudip Kumar; |
| Examination Committee(s) | Stevens, Willem F. ;Suwalee Chandrkrachang ;Parkorn Nuchnoi ;Didier, Montet; |
| Scholarship Donor(s) | King's Scholarship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1998 |