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Title: Determination of Hydroxycitric Acid (HCA) content in Roselle (Hibiscus sabdariffa L.) through extraction of Potassium Hydroxycitrate and High Performance Liquid Chromatography (HPLC)
Authors: Halimaton Saadiah Othman
Keywords: Roselle
Issue Date: 2011
Publisher: Universiti Sains Islam Malaysia
Abstract: Determination Of hydroxycitric Acid (HCA) Content In Roselle (Hibiscus sabdariffa.L.) Through Extraction Of Potassium Hydroxycitrate And High Performance Liquid Chromatography (HPLC). Roselle (Hibiscus sabdariffa L. from family Malvaceace is relatively a new crop in Malaysia. Roselle is rich with vitamin C and anthocyanins but recent discovery showed that roselle also contains hydroxycitric acid (HCA). This study was conducted to extract HCA in the form of potassium hydroxycitrate and to determine the concentration of potassium hydroxycitrate in roselle accessions through two comparative HCA extraction method i.e the original extraction method and modified extraction method which used activated charcoal. Eleven samples were used in this study which were roselle Accession 2,3,6,12 and 21 and their respective mutants HS0275-30-4-4-1-1-1, HS0275-30-3-3-1-1-1, HS 03100-29-2-1-17-15-1,HS03100-29-7-1-6-3-1, HS1250-18-18-1-1-1-1 and HS1250-1-18-1-1-1-1 while asam keping (Garcinia atroviridis ) and G. cambogia which were known to contain HCA were used as controls. HCA was extracted from dried dried roselle calyces using methanol and HCA extracted was then stabilised in the form of potassium hydroxycitrate, a form that is both stable and biologically active. Potassium hydroxycitrate was comfirmed through HPLC analysis using standard potassium hydroxycitrate. Results showed that the extracts from both extraction methods gave differences in term of colour. Original extraction method gave extracts colours ranged from beige, pale brown and brown. Modified extraction method gave extract colours from white to offwhite. Original extraction method gave Acc. 21 with the highest yield of extract with 17.8%.The extract yield in modified HCA extraction method was slightly decreased due to the elimination of all water soluble compounds by activated charcoal, however showing Acc. 21 and HS03100-29-7-1-6-3-1 both with 6.0%. pH of 5% extract solution from both extraction methods showed pH value ranged around 7.0-8.6 which were all alkaline. Extracts from both extraction methods showed that they were highly soluble in water and aqueous methanol while soluble in hydrochloric acid. The extracts were insoluble in benzene, chloroform and methanol. All their physico-chemical characteristics complies all the characteristics the same to the control used. HPLC results proved that potassium hydroxycitrate were present in all of roselle samples and controls. The retention time of potassium hydroxycitrate was around 4.500 min. For original extraction method, potassium hydroxycitrate concentration was the highest in Acc. 6 with 82.1mg/100g or 0.082%. While in modified extraction method, the highest potassium hydroxycitrate concentratuon was in HS1250-1-18-1-1-1-1 with 42.5mg/100g or 0.043%. This study demonstrates that the roselle in UKM have content of HCA and through appropriate HCA extraction method, the aim for product development of HCA-based product derived from roselle can be proceeded and succeeded.
Description: Thesis (M.Sc)-- Faculty of Science and Technology, Universiti Sains Islam Malaysia, 2011
Appears in Collections:Master

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chapter 1.pdf4 MBAdobe PDFView/Open
chapter 2.pdf36.06 MBAdobe PDFView/Open
chapter 3.pdf58.56 MBAdobe PDFView/Open
chapter 4.pdf3.45 MBAdobe PDFView/Open
references.pdf55.29 MBAdobe PDFView/Open

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