Design and development of laboratory scale freeze dryer for tangerine juice powder | |
| Author | Chouw Inprasit |
| Call Number | AIT Thesis no. AE-90-17 |
| Subject(s) | Tangerine Food, Freeze-dried |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | A laboratory scale freeze dryer was designed and developed to produce tangerine juice powder and also to study the effect of freeze drying process on the quality of prod u ct. The main components of freeze dryer consist of chamber, refrigeration unit, vacuum pump, and plate heat exchanger . Electrical plate heat exchanger was us e d instead of hot water plate h eat exchanger for reduced the heating time . The effete of process parameter e . g. p late temperature on the quality of powder obtained in term of color change and ascorbic acid loss was found to b e non-significant at 50 and 60°C has a plate temperature . How eve r, at 7 0 °C plate temperature , product has a high loss of ascorbic acid and browning development . Optimum condition for freeze drying is at 60°C plate temperature on the basis of color change, ascorbic acid, and energy consumption. The best sample was at 60°C plate temperature and was selected for the determination of physical properties. The physical properties of powder such as particle size , loose bulk density, packed bulk density, and reconstitution time were 248. 17 w.m, . 0 . 59 g /ml, 0.83 g/ml, a nd 4.5 minutes respective l y. Total bacteria count for non-pasteurized juice powder about 3,000 colonies per gram of powder but in pasteurized juice powder less than one colony per gram of powder was presented. Energy consumption from experiment was 130, 376. 36, 167, 134. 25, and 222,460.57 kJ/kg of powder at 50, 60, and 70°C plate temperature respectively. The sensory evaluation test of color of the reconstituted juice reveal e d a slight difference from the fresh juice , however more significant differences were observed for taste and flavor since texture were damaged by grinding the powder after freeze drying. |
| Year | 1990 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Athapol Noomhorm |
| Examination Committee(s) | Jindal, Vinod Kumar |
| Scholarship Donor(s) | The Royal Government of the Netherlands |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1990 |