| Author | Pilairuk Boonyai |
| Call Number | AIT Thesis no.PH-00-18 |
| Subject(s) | Soymilk--Drying
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Masters of
Science |
| Publisher | Asian Institute of Technology |
| Abstract | This study investigated the production of soymilk powder using two drying methods, namely spray drying and spouted bed drying. Soymilk at two concentration levels (1 O and 20%) was subjected to different drying conditions to evaluate their effects on powder properties. Experimental drying conditions included the inlet air temperature (175, 195 and 205°C), feed flow rate (2, 3 and 4 kg/hr), and atomizer's speed (25000, 30000 and 35000 rpm). During drying operation, ambient air temperature and relative humidity along with outlet air temperature were continuously recorded. Spray-dried powder samples were analyzed for moisture content, color, particle density, particle size distribution, and solubility. The main factors having significant effects on the powder properties were identified using linear correlation analysis. Spouted bed drying in a bed of inert particles was carried out at the optimum conditions reported earlier for the drying of soymilk. Properties of powder were determined and compared to those of spray-dried powder. The effect of addition of maltodextrin was also studied in both drying methods. Spray-dried soymilk had lower moisture content (1.9-3.6%) and particle density (<0.95g/ml for most samples) than soymilk powder from spouted bed drying (3.7-8.3%, and 1.11-1.25g/ml, respectively). Color of soymilk powder from spouted bed drying was whiter. Particle size of spray-dried powder were smaller (<75μm) and more uniformly distributed than soymilk from spouted bed drying (75μm < size < 250μm). Spray-dried powder was more soluble. The performance of the two dryers was compared in terms of thermal efficiency, evaporative efficiency and specific heat consumption for evaporation. Spouted bed drying operation had lower thermal and evaporative efficiencies. This drying technique used relatively more heat in evaporation of water. |
| Year | 2000 |
| 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 | Postharvest and Food Process Engineering (PH) |
| Chairperson(s) | Jindal, Vinod K.; |
| Examination Committee(s) | Athapol Noomhorm ;Rakshit, Sudip K.; |
| Scholarship Donor(s) | The Royal Thai Government; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2000 |