High power ultrasonication assisted extraction of soybean isoflavones and effect of toasting | |
| Author | Thawunporn Pananun |
| Call Number | AIT Thesis no.FB-11-05 |
| Subject(s) | Soybean Soyfoods |
| Note | A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. no.FB-11-05 |
| Abstract | The effect of high power ultrasonicati on (HPU) during extraction of soybean isoflavones and components, including total phenolics and DPPH radical scavenging activities were evaluated. Soybean isoflavones were extracted from defatted soy flakes using HPU system operating at 20 kHz and 2.2 kW and varying amplitudes (18 - 54 μ m) for 1 and 3 minutes. The solvent evaluated for isoflavones extraction was a mixture of 59% aqueous acetonitrile and 11% 0.1 M HCl at samples - to - solvent ratios of 0.1:1 and 0.2:1. A control (unsonicated) extraction was sti rred with magnetic bar for 2 hours. Genistein content, DPPH radical scavenging activities , and total phenolics were measured with spectrophotometer at 382, 517, and 760 nm, respectively. Isoflavone components were measured with HPLC. Results indicated 1. 2 to 1.5 times more genistein recovery at 1 min HPU compared to control and t he recovery was lower with higher sonication power levels. Similar values were obtained for 3 min treatments also. The total phenolics decreased for sonicated samples relative t o control (6 to 32% reduction at 1 min, and 19 to 36% reduction in3 min sonication). Radical scavenging effect also decreased to about 40% for HPU treatments. HPLC analysis of sonicated (at 54 μ m, 3 min) and control samples showed that total isoflavones contents of sonicated samples increased from 600 to 5813 μ g/g of extract. Similarly, major isoflavone components, genistein, daidzein, and glycitein contents, also showed increase of about 10 - fold. The particle size analysis showed that the HPU for 3 min reduced the d(0.5) value of treated soy flakes to about 60 μm from an average control d(0.5) of 530 μm. The breakdown in soy flakes cotyledon matrix due to HPU presumably prompted higher levels of isoflavones extraction. In addition, the effect of toast ing time at 150 o C on isoflavones component and total pheno lic recovery was studied in both HPU - assisted and convectional method , it was investigated that at 2 hr. of toasting time for HPU - assisted extraction of defatted soy flake led to the highest aglyco ne concentration, which affect ed the highest total phenolic recovery . From the whole result, it showed that HPU can be utilized in extracting more isoflavones from defatted soy flakes, however, some reduction in total phenolics and radical scavenging abil ity occurred while toasting defatted soy flake before HPU - assisted extraction seemed effective for soy isoflavone extraction . |
| Year | 2011 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. no.FB-11-05 |
| 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) | Rakshit, Sudip Kumar;Anal, Anil Kumar;Buddhi Lamsal; |
| Scholarship Donor(s) | RTG Fellowship; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2011 |