| Author | Savitree Jungsakulrujirek |
| Call Number | AIT Diss. no. AE-97-02 |
| Subject(s) | Tangerine juice--Thailand
|
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Technical Science |
| Publisher | Asian Institute of Technology |
| Abstract | The effects of harvesting time and fruit size on the distribution of limonin content in tangerine fruit (Citrus reticulata, Blanco) was studied. Specifically, effects on limonin content of whole fruit and each fruit part, as well as on quality of extracted juice were investigated. The process of limonin reduction by XAD-16 resin in batch process, packed bed and fluidized bed columns were also studied. Results showed that seed had the highest limonin content of 1.480 mg limonin/ g sample while juice sacs had the lowest of 0.002 mg limonin/ g sample. Increasing harvesting time from 8 to 12 months showed corresponding decrease in the amount of limonin in flavedo, albedo and seed while the Brix/acid ratio as index of flavor quality increased. The fruit size showed no effect on limonin concentration of whole fruit and all fruit parts, and no effect on the quality of extracted juice. Limonin reduction in batch process, optimum contact time for 5 g XAD-16 resin to achieve maximum limonin reduction was 30 to 32 minutes. Slight variation of titratable acidity and total soluble solids occurred with increased contact time. The capacity of XAD-16 resin for limonin adsorption was 0.33 mg limonin/ g XAD-16 resin. Ten grams of used XAD-16 resin were regenerated by washing with 100 mL distilled water to remove residues and washing four times with 100 ml of 0.05 M NaOH to remove all limonin. For packed bed column, juice with different suspended pulp content (1, 3 and 5%) was prepared by varying the applied centrifugal force. The required contact time increased as the pulp content of the juice increased while higher pulp content resulted in more reduction of limonin. The titratable acidity and the total soluble solids slightly changed. In fluidized bed column, more retention time occurred due to clogging while limonin reduction sharply decreased. The titratable acidity and total soluble solids were almost unchanged. Sensory evaluation by paired comparison test between fresh juice and limonin reduced juice by fluidized bed column shown significant difference in bitterness at 5% confidence level. |
| Year | 1997 |
| Type | Dissertation |
| 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;Reutergardh, Lars Baetz;Yakupitiyage, Amararatne; |
| Scholarship Donor(s) | Royal Thai Government (RTG); |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 1997 |