Study of vacuum microwave-assisted extraction of proanthocyanidins from grape seed | |
| Author | Yuwadee Poosiripinyo |
| Call Number | AIT Thesis no.FB-09-19 |
| Subject(s) | Grapes--Drying Extraction (Chemistry) |
| Note | A thesis submitted in partial fulfillment of the requirements for thedegree of Master of ScienceinFood Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. no. FB-09-19 |
| Abstract | Three different extraction methods were studied to extract proanthocyanidins from grape seed including Soxhlet extraction (SE), Microwave-assisted extraction (MAE), and Vacuum microwave-assisted extraction VMAE). Soxhlet extraction was operated to select the suitable raw material used for the other advance extraction technique (MAE and VMAE). There were two varieties of raw materials of grape seed including Shiraz and Pok Dum. Shiraz seed was dried by sun dry and stored for and stored for seven months before analysis while Pok Dum seed was divided into two categories that were blanched seed and fresh seed. The result expressed that the most suitable variety was fresh Pok Dum seed that proanthocyanidins content was 670.85 mg of CE/ g of GSP (mg of catechin equivalent/ g of grape seed powder). For MAE, the extraction temperature, extraction time, and solvent to material ratio were studied. The extraction temperature was varied in three levels (50,60, and 70°C) and the optimum level was 50°C that offered 805.34 mg of CE/ g of GSP. The extraction time was varied in four levels (10, 20, 30, and 40 min.) and the highest proanthocyanidins content in grape seed extract was 761.56 mg of CE/ g of GSP at 10 min. The solvent to material ratio was studied in five levels (1:10, 1:15, 1:20, 1:25, and 1:30 g/ml) and the highest proanthocyanidins content was 812.95 mg of CE/ g of GSP at 1:10 g/ml. At the optimum condition ( 50°C, 10 min, and 1:10 g/ ml of solvent to material ratio), proanthoyanidins content in grape seed extract was 819.99 mg of CE/ g of GSP. The vacuum microwave-assisted extraction (VMAE) was studied in this work by varying the degree of vacuum in four levels (0, 20, 40, and 60 kPa) and the highest amount of proanthocyanidins content was 887.17 95 mg of CE/ g of GSP at 60 kPa. Proanthocyanidins in grape seed extract obtained from SE, MAE, and VMAE was compared. VMAE offered the highest proanthocyanidins content in grape seed extract and antioxidant activity of grape seed extract was 68.80% DPPH radical scavenging activity. The stability of proanthocyanidins in grape seed extract in different storage condition including room temperature (26°C) and refrigerator (4°C) was investigated and the suitable condition for grape seed extract storage was refrigerator. The stability of proanthocyanidins in grape seed extract after passing heat process was also investigate and the reduction of proanthocyanidins was parallel to the increasing temperature. The antibacterial property of grape seed extract including disc diffusion technique and minimal inhibitory concentration technique was studied with Escherichai coli 780 (gram-negative bacteria) and Staphylococcus aureus 029 (gram-possitive bacteria). The result showed that grape seed extract had the antibacterial properties and the less concentration of grape seed extract to inhibit the growth of E.coli 0157 780 and S.aureus 029 was 25 and 12.5 mg/ mI, respectively |
| Year | 2009 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. no. FB-09-19 |
| 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;Salokhe, Vilas M.; |
| Scholarship Donor(s) | Her Majesty Queen of Thailand Scholarship; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2009 |