Post harvest technology and assessing quality of Mekong Delta rice | |
| Author | Chau Duy Khang |
| Call Number | AIT Thesis no.FB-07-06 |
| Subject(s) | Rice--Mekong River Delta (Vietnam and Cambodia) Rice--Post harvest technology--Mekong River Delta (Vietnam and Cambodia) |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. FB-07-06 |
| Abstract | Farmers in Mekong Delta usually cut paddy by sickle and then collected it for the threshing stage. Some cutting machines were used but they are not efficiency because they work only in certain condition, and are expensive. Nearly 100% of paddy grains are separated from paddy tree by threshing machine. Two popular threshers in Mekong Delta were threshing machine having threshing drum with cycle tooth and threshing drum with flat tooth. Sun light was the simplest and cheapest drying method which most of farmers prefer to use. Some other drying methods such as the horizontal grid static dryer and the drying tower were not widely accepted in Mekong Delta due to high price and short time using. The traditional method for storing paddy is in large baskets or in small wooden granaries, or in jute bags of 50 to 100 kg. Millers in Mekong Delta store paddy in jute bags in an open warehouse, except for a few modem mills that use bulk bins inside the warehouse. With the summer crop almost all farmers in the Mekong Delta sell fresh paddy immediately after harvesting. Few farmers dry wet paddy first and then sell it to middleman. Big milling factories have purchase department and drying system so they can buy fresh paddy or dried paddy directly from farmers. Small milling factory has no drying system so they could not buy fresh paddy, they have to buy dried paddy from farmers or middleman. With the winter crop the situation was opposite. Farmers dry paddy in the field and sell paddy containing about 14% moisture content in wet basis. Three aromatic rice varieties used to determine milling quality were Jasmine 85, harvested in winter crop (JAW), in summer crop (JAS). Both of them are Vietnamese paddy varieties. Khao Dawk Mali 105 (KDML) of Thai paddy varieties was also used. Two non-aromatic rice varieties also used were OMCS 2000 (OMCS) from Vietnam and Chainat 1 (CNT 1) from Thailand. KDML had highest head yield among aromatic rice about 50.6% while head yield of JAS and JAW was 43.2% and 47.4% respectively. CNT1 and OMCS had 51.2% and 40.0% head yield respectively. Physical properties such as size, shape, and one-hundred grains weight, physicochemical properties such as amylose content, gel consistency, alkali spreading value, cooking quality (Cooking time, volume expansion, water absorption), eating quality (Texture of cooked rice), pasting properties (Peak and final viscosity, peak time, breakdown, set back) were determined among above varieties. Results showed that the cultivation condition is an important factor that influence in cooking and eating quality of rice. The cooked rice of jasmine harvested in winter crop was harder than one in summer crop in term of texture. The rice flour of JAW had more final viscosity than JAS with the same peak time. The quality of milled and cooked rice of Vietnamese rice varieties were different with Thai rice varieties of both aromatic and non-aromatic rice. |
| Year | 2007 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. FB-07-06 |
| 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 | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Athapol Noormhorm; |
| Examination Committee(s) | Rakshit, Sudip K;Jayasuriya, Hemantha P; |
| Scholarship Donor(s) | ADC Company, Vietnam;Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2007 |