Effect of extrusion conditions on the physicochemical properties of a snack made from purple rice (Hom Nil) and soybean flour blend | |
| Author | Korntip Thititumjariya |
| Call Number | AIT Thesis no.FB-09-22 |
| Subject(s) | Snack foods Rice flour Soy flour |
| Note | A thesis submitted in partial fulfillment of the requirements for the Degree of Maste r of Science in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. no. FB-09-22 |
| Abstract | A laboratory scale single screw extruder was designed and developed to study the effect of feed moisture content (15%,17%,19%), barrel temperature (150,170, 190°C) and screw speed (350, 400, 450 rpm) on physiochemical properties of Horn Nil rice and soybean snack. The physiochemical properties of the product including expansion ratio, density, water absorption index (W AI), water solubility index (WSI) and hardness were investigated. The performance of laboratory scale single screw extruder was evaluated in term of temperature profile and production rate. The extruder can maintain temperature during extrusion. The barrel temperature was be slightly fluctuated when run at high screw speed. The extruder can produce Horn Nil rice and soybean snack about 1.60 kg/hour on dry weight basis for the tested condition (15% feed moisture content, 190°C barrel temperature and 450 rpm screw speed). The results for the effect of extrusion conditions on physiochemical properties of extrudates indicated that feed moisture content and barrel temperature were the most importance factor that effect on physiochemical properties of products. Screw speed had a slight effect on all properties of products. Increasing feed moisture content resulted in extrudates with a lower expansion ratio, higher density, higher WAI, lower WSI and higher hardness. Increasing temperature caused an increase in expansion ratio, WSI and W AI but caused a decrease in density and hardness. The values of expansion ratio, density, WAI, WSI and hardness varied from 2.43-3.21, 0.13-0.29 glcm³, 3.24-3.97 gig, 13.46-21.77%, and 33939.02-53622.92 g, respectively within the combination of variables studied. Increasing feed moisture content from 15% to 19% caused a range of 4.60-1 0.90% decrease in expansion ratio and 29.67-51.76% increase in hardness. Increasing barrel temperature from 150°C to 190°C resulted in a range of 13.04-21.74% increase in expansion ratio and 5.26-17.99% decrease in hardness. The result of sensory evaluation showed no significant in the overall acceptance score for the samples for the conditions of feed MC 15% 170°C 450 rpm, feed MC 15% 190°C 400 rpm and feed MC 15% 190°C 450 rpm. Horn Nil rice and soybean snack produced from 15% feed MC at 170°C barrel temperature and 450 rpm screw speed obtained the highest hedonic score of appearance, hardness and overall acceptance from panelists. Thus, this condition was selected as optimum extrusion to produce Horn Nil rice and soybean snack for this extruder |
| Year | 2009 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. no. FB-09-22 |
| 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;Salokhe, Vilas M.; |
| Scholarship Donor(s) | HM Queen’s Scholarships; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2009 |