Effect of extrusion condition on the physiochemical properties of brown rice and soybean snack | |
| Author | Prueksa Sawardsuk |
| Call Number | AIT Thesis no.FB-07-05 |
| Subject(s) | Snack foods Brown rice Soyfoods |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. FB-07-05 |
| Abstract | A study on the effects of feed moisture content, barrel temperature and screw speed of the single screw extruder on the physiochemical properties of extrudate were investigated. Preliminary tests were done to evaluate the performance of modified laboratory single screw extruder. Properties of brown rice and soybean extrudate such as expansion ratio, density, Water absorption index (WAI), Water solubility index (WSI) and hardness were determined at different feed moisture content (15%, 17%, 19%), barrel temperature (100, 120, 140°C) and screw speed (150, 180, 207 rpm). An original SSE faced problem on cleaning and the product was burnt. A modified SSE on barrel was change to open on the top which was only two parts instead of 3 sections as the original one. The die hole was also modified from straight hole to tapered shape. The flow of product through die was smooth, puffed and the machine was easy to clean. The modified barrel could not resist pressure and broken during extrusion. The performances of modified laboratory single screw extruder on temperature profile and production rate were evaluated. During extrusion at highest screw speed, barrel temperature was higher than setting temperature about 5°C. The extruder can produce puffed brown rice and soybean snack 8.87 kg/hour on dry weight basis at the test condition. The result showed that increasing feed MC led to increase density, WAI and hardness and decrease in WSI. Increasing temperature led to increase ER, WSI and hardness and decrease density and WAI. Screw speed led to decrease ER and WSI. Hardness of brown rice and soybean snack decreased with temperature increased when extruded at 150rpm but hardness increased with temperature increased during extrusion at 180 and 207 rpm. Result of sensory evaluation showed no significant effect in samples from condition; feed MC 15% 120°C 180rpm, feed MC 15% 140°C 150rpm, feed MC 15% 140°C 207rpm and feed MC 17% 120°C 180rpm. Brown rice and soybean snack that was produced from feed MC 17% at barrel temperature 120°C and screw speed 180 rpm was given a high sensory score by panelists (7.08, like moderately) therefore this condition was selected as the optimum extrusion condition. |
| Year | 2007 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. FB-07-05 |
| 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 Noomhorm; |
| Examination Committee(s) | Rakshit, Sudip Kumar;Ranamukhaarachchi, S. L.; |
| Scholarship Donor(s) | RTG Fellowship; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2007 |