Spray drying of Tamarind concentrate and its quality evaluation | |
| Author | Truong Vinh |
| Call Number | AIT Thesis no. AE-94-13 |
| Subject(s) | Fruit juices--Vietnam Spray drying |
| Note | A thesis submitted in partial fulfillment of the requirements for the Degree of Master of Engineering, School of Environment, Resources & Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. AE-94-13 |
| Abstract | In this study, the spray drying process of fresh tamarind juice was investigated to obtain the final product in free-flowing powder form. Using an experimental spray-drying set up, the effect of various process parameters were evaluated for selecting optimum operating conditions and quality attributes of spray-dried tamarind powder. The results of numerous preliminary experiments revealed that it was not possible to produce tamarind powder without the addition of malto-dextrin at least equal to the 20 % solid content of the juice for spray drying. It was further established that malto-dextrin should be about 45 % of the solid content of the tamarind juice. Experiments using a 3x3 factorial design showed that air temperature, air velocity and juice concentration had significant effects on moisture content and recovery of tamarind powder. Drying air temperature was the most important factor affecting the powder properties. The process conditions for best performance were determined to be l 50°C for air temperature, 0.31 mis for air velocity and 7 % for juice concentration. The Henderson and Chung and Pfost equations best represented the experimental moisture sorption data for the tamarind powder.The limiting values of equilibrium relative humidities at the temperature of 22, 32 and 42°C were found to be about 36, 26 and 12 %, respectively in order to maintain the free-flowing state of tamarind powder. In higher humidity environments, the powder was transformed into a wet paste but could achieve equilibrium up to a relative humidity level of 75 %. Non-equilibrium moisture adsorption conditions prevailed above these relative humidity levels. The rates of moisture adsorption of tamarind powder could be determined from the relationships between moisture ratio and time which were best represented by a modified-log model. The moisture adsorption rates were mainly affected by the relative humidity and there was no statistically significant influence of the temperature in 22 to 42°C range. The uniaxial compaction behavior of tamarind powder could be represented by a simple log model. Also apparent similarities were observed between reconstituted and fresh tamarind juice. |
| Year | 1994 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AE-94-13 |
| Type | Thesis |
| School | School of Environment, Resources, and Development |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Jindal, Vinod Kumar ; |
| Examination Committee(s) | Athapol Noomhorm ;Ilangantileke, S.G. ;Vincent, Jean-Claude ; |
| Scholarship Donor(s) | Ecumenical Scholarship Programme German ; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 1994 |