| Author | Benjar Chutintarasri |
| Call Number | AIT Thesis no.AE-91-29 |
| Subject(s) | Fruit juices
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science |
| Publisher | Asian Institute of Technology |
| Abstract | A study of concentrating pineapple juice by Osmotic distillation and clarification of
pineapple mill juice by Ultrafiltration was made. The effects of process parameters such as flow
rates and temperatures were studied on osmotic distillation process whereas the methods used
in extracting mill juice, hydraulic press and blender and the aforementioned process parameters
combined with enzyme pretreatment were investigated by ultrafiltration process.
In osmotic distillation process, the results showed that the feed flow rate 4 1/min at 50 °C
gave the highest processing capacity of 2.87 kg/m/hr.
In clarification process, the rate of extracting juice from pineapple shell with hydraulic
press and juice blender showed that the smaller the pineapple shell size, the more juice yield.
Pineapple mill juice was clarified by an ultrafiltration pilot plant tubular HFM 180 membrane
with a surface area of 0.4 m2 and molecular weight cut off 18,000 Daltons. Enzyme pretreatment
reduces the viscosity (from 1.27 to 1.04 cps), turbidity from 875 to 725 NTU and produces a
clear product. The operating transmembrane pressure of 4 bars at ambient temperature, the
enzyme treated juice gave maximum filtrate production of 46.73 1/m /hr. Enzyme pretreatment
and high transmembrane pressure gave higher flux rate. The viscosity of pineapple syrup
prepared from enzyme treated mill juice was lower than the untreated control syrup. The
viscosity reduction of treated syrup was 50.2% at 20 Brix and 79% at 40 Brix.
Analysis of reducing sugar from syrup and clarified mill juice showed that sucrose,
glucose and fructose were present. Moreover, ultrafiltration process reduced the herbicide
residues level (Ametryn and Atrazine) from 0.93 and 1.3 ppm before process to 0.11 and 0.15
ppm after processing |
| Year | 1991 |
| 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) | Athapol Noomhorm; |
| Examination Committee(s) | Jindal, Vinod Kumar;Ilangantileke, S.G.; |
| Scholarship Donor(s) | DAAD (The Government of Republic of Germany); |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1991 |