Modeling drying kinetics of red chillies in a combined infrared and hot air rotary dryer | |
| Author | Mhindukulasuriya, S. D. F. |
| Call Number | AIT Thesis no.AE-07-03 |
| Subject(s) | Chili--Drying Drying apparatus. |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Agricultural Systems and Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. AE-07-03. |
| Abstract | Chillies arc important in almost every Asian country as an essential ingredient in meals and also as one of the most important cash crops grown in those countries. Existing drying methods have many limitations and have unable to fulfill the requirement of farmers. A laboratory scale prototype of combined infrared (IR) and hot air rotary dryer was designed and developed so as to investigate the drying kinetics of chillie. Preliminary studies were conducted in hot air and fluidized bed dryers within a temperature range of 45 to 65 °C and air flow rate of 2.4 m3/min in the fluidized bed dryer. Modeling and drying kinetics of red chilies were determined in combined IR and hot air rotary dryer within the temperature range of 50 to 70 °C. Quality parameters such as capsaicin content, surface color chromaticity a*, power consumption and retention time were compared. Optimum drying conditions were determined in each dryer under each operating mode. Thirteen different thin layer drying models were used to correlate the drying characteristics of chillies. Among all the models, the Midilli model was found to be the best for explaining the drying behavior of chillies in all types of dryers. The reduction of color chromaticity coordinate a* and capsaicin percentage, power consumption were found to be higher in fluidized bed dryer than the hot air oven dryer. The overall performance of the chillie dried at 60 °C was the best in hot air dryer, whereas it was 50 °C in fluidized bed dryer. But quality wise best temperature is 45°C in hot air dryer, whereas it is 50°Cin fluidized bed dryer. Overall performance of chillie drying was slightly higher in the hot air dryer in terms of color, capsaicin content, power consumption and retention time of chillie in the dryer. The highest capsaicin reduction and color chromaticity coordinate a* were observed in the IR mode whereas the lowest reduction observed in the hot air mode. The best temperature for chillie drying in hot air mode was 70 °C, whereas 50, 55 °C both temperatures were suitable in IR mode, and 70 °C was best for the combined mode when considering quality parameters with power consumption and retention time. However the quality wise the best temperature was 50°C in each and every operating mode. Overall performance of chillie drying was best in the combined IR and hot air mode when considered colour, capsaicin content, power consumption and retention time of chillie in the dryer. The combined dryer shows better performance than the hot air and fluidized bed dryers in chillie drying. |
| Year | 2007 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AE-07-03. |
| 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 | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Jayasuriya, H.P.W.; |
| Examination Committee(s) | Salokhe, V. M.;Athapol Noomhorm.; |
| Scholarship Donor(s) | NORWAY.; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2007 |