| Author | Petcharat Sangkamkad |
| Call Number | AIT Thesis no.FB-13-12 |
| Subject(s) | Longan
|
| Note | A thesis submitted in partial fulfillment of the requirements for the d egree of Master of Engineering in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. no.FB-13-12 |
| Abstract | Longan seed is byproduct from longan p rocess. It contains abundant bioactive compounds especially polyphenols. In th is present work, the effects of extraction technique, extraction temperature and ethanol concentration on the yield of total phenolic compounds, tannin and their antioxidant activities were investigated . U ltrasound - assisted extraction showed more effective of phenolic extraction when compared to shaking. The highest content of phenolic compounds, tannin and their antioxidant activity were 73.76 mgGA/gDM, 23.55 mgTA/gDM, and 39 .60%, respectively. The optimum condition for phenolic extraction was ultrasonic at 50 °C with 40% ethanol. Addition of seed extract in longan pulp juice extremely enhanced the yields of phenolic compounds, tannin and their antioxidant activity. The phenol ic and tannin contents of pulp juice were increased from 0.11 to 2.70 mgGA/ml and 0.09 to 0.78mgTA/ml, respectively. Nevertheless, the longan pulp juice addition with seed extract showed lower content of phenolic, tannin and antioxidant activity compared t o seed beverage. Enzymatic treatment is another technique for phenolic extraction. Polyphenols from longan seed were extracted by shaking technique at constant rate. Also, α - amylase was used to hydrolyze starch - polyphenol complexes and enhance sweetness of longan seed beverage. Enzymatic treatment at 40 °C with water solution was the optimal condition for extraction of phenolic compounds from longan seed. The highest content of phenolic compounds, tannin and their antioxidant activity were 4.80 mgGA/ml, 2.2 9 mgTA/ml, and 50.54 % , respectively . For reducing sugar, the treatment at 40 °C with buffer solution pH 5.5 was optimal condition which highest dextrose equivalent, 80.20 %. T he effect of pasteurized temperature on the yields of phenolic compounds, tannin, and their antioxidant activity was studied. Longan seed beverage was pasteurized using Ohmic heating at various temperatures for 2 min. The result showed that pasteurization at different temperatures was not effect to phenolic and tanni n contents of beverage. The yields of phenolic compounds, tannin, and their antioxidant activity were not significant change after Ohmic heating. |
| Year | 2013 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. no.FB-13-12 |
| 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 | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Athapol Noomhorm; |
| Examination Committee(s) | Anal, Anil Kumar;Muanmai Apintanapong; |
| Scholarship Donor(s) | Royal Thai Government Fellowship; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2013 |