Effect of carbon dioxide fumigation under pressure on insect mortality and rice quality | |
| Author | Siriporn Sangsumritphon |
| Call Number | AIT Thesis no.FB-04-10 |
| Subject(s) | Rice---Quality Carbon dioxide Rice--Fumigation |
| 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. FB-04-10 |
| Abstract | Effect of fumigation technique by using C02 and pressure on insect mortality and the qualities of fragrance rice (Kao Dok Mali 105; KDML 105) was studied. Rice samples with both insect species were fumigated with 60%, 80% and 100% C02 to investigate the effect of C02 fumigant. The results showed that higher level of %C02 gave faster mortality rate. Fumigation with the fastest rate of 100% C02 need 21 hrs to reach 100% mortality of S. zeamais and 12 hrs for T. castaneum to get rid of all insects. The color of rice samples in terms ยท of yellowness and brightness were not changed. Increase level of %C02 in fumigation technique resulted in increasing pasting time but decreasing of breakdown value. With 100% C02 fumigation enhanced final viscosity, consistency and set back value since retrogradation was increased and also increased the hardness of the cooked rice meanwhile decreased the water absorption of the samples. In order to study the effect of pressure in fumigation technique, rice samples were pressurized with air at 4, 6 and 8 bars. The result illustrated an increase in pressure of fumigation accelerated the insect mortality. Fumigation under air pressure of 8 bar provided the quickest insect mortality rate and required about 30 hrs and 40 hrs to attain 100% mortality of S. zeamais and T. castaneum respectively. The color of pressurized rice samples were still not affected by high pressure condition. All pasting parameters were increased except peak viscosity which was not changed. Breakdown value also decreased. Hardness of the cooked rice sample was gradually increased from the control in 4 and 6 bar conditions and was significantly higher than the control with 8 bar fumigation. Water absorption of the pressurized samples was lower than the control because of more hardness of cooked rice in pressurized treatments than the control. From the Combined technique of 100% C02 under various pressures level of 4, 6 and 8 bars was studied in attempt to gain the optimum fumigation condition. For fumigation with 100% C02 under 8 bar gave the fastest insect mortality that need only 2 hrs which was the shortest fumigation to gain 100% mortality in both species. It was the main advantage of the combined technique of fumigation. Color of the treatments was not changed after fumigation. The quality result of the cooked rice in term of pasting quality was not changed much and the hardness with water absorption was not changed. |
| Year | 2004 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. FB-04-10 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Athapol Noornhorm |
| Examination Committee(s) | Jindal, Vinod K.; Rakshit, Sudip K. |
| Scholarship Donor(s) | Royal Thai Government Scholarship |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2004 |