| Author | Ruba, Andres Balderian |
| Call Number | AIT Thesis no. AE-89-22 |
| Subject(s) | Orange juice
|
| 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 | Essential thermophysical properties (boiling point rise and
viscosity) for the optimization of operating parameters for concentrating
tangerine juice was investigated. Likewise, some of the quality changes
caused by the evaporation process was also studied.
A boiling point apparatus and its accesso/ries for the determination
of t he boiling point of tangerine juice was fabricated. The boiling point
rise (BPR) was as high as 5.05 °C for 66.74 °Brix tangerine juice at 700
mbar pressure. The BPR increased correspondingly with an increase in
pressure and concentration ( 0 Brix) of soluble solids as total sugar
equivalent. The relationship can be described best by the developed empirical model. This expression was found to be superior to other predictive equations for the rise in boiling point.
Concentrated tangerine juice (21. 26 to 66. 49 °Brix) is a pseudoplastic fluid as determined by the Brookfield rotational
viscometer. Apparent viscosity was an exponential function of concentration of soluble solids. The simple power law model adequately described the flow data. The consistency index of the power law model
increased exponentially with concentration of soluble solids in the
juice .
The pressure during evaporation significantly affected the quality
(ascorbic acid retention and nonenzymatic browning) of the concentrated
tangerine juice. Of t he different pressures studied, 123 mbar was found
to be the most suitable pressure. At this pressure level, the reconstituted juice had 78.35% retention of ascorbic acid and a nonenzymatic
browning index of 0 .100 which was not significantly different from that
of t he fresh tangerine juice. |
| Year | 1989 |
| Type | Thesis |
| School | School of Environment, Resources, and Development |
| 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) | Illangantileke, Sarath G. ; |
| Examination Committee(s) | Tran, Francis T. ;Panda, Tapobrata ; |
| Scholarship Donor(s) | Federal Republic of Germany (DAAD); |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1989 |