Ah Ngan Ma

article

Determination of Coenzyme Q₉ and Q₁₀ in Developing Palm Fruits

Mei Han Ng, Yuen May Choo, Ah Ngan Ma, Cheng Hock Chuah, more

Journal of the American Oil Chemists' Society > 2009 > 86 > 3 > 201-205

A series of biochemical changes took place as oil palm fruits developed into maturity. Among these are the active synthesis of glycerides as well as unsaponifiable compounds such as carotenes, vitamin E, sterols and squalene. Coenzyme Q₉ and Q₁₀ were found to be present at different stages of the oil palm fruits development. The presence of coenzyme Q₉ was detected as early as 4 weeks after anthesis...

article

Selective extraction of palm carotene and vitamin E from fresh palm-pressed mesocarp fiber (Elaeis guineensis) using supercritical CO2

Harrison Lik Nang Lau, Yuen May Choo, Ah Ngan Ma, Cheng Hock Chuah

Journal of Food Engineering > 2008 > 84 > 2 > 289-296

Fresh palm-pressed mesocarp fiber was subjected to supercritical carbon dioxide (SC-CO ₂ ) extraction at 40°C to produce two fractions of fiber oil enriched with vitamin E and carotene, respectively. The extraction was carried out in three stages using continuous extraction technique; firstly to extract vitamin E and squalene enhanced fraction at 10MPa, secondly to remove bulk triglycerides...

article

Very long chain fatty acid methyl esters in transesterified palm oil

Chiew Wei Puah, Yuen May Choo, Ah Ngan Ma, Cheng Hock Chuah

Lipids > 2006 > 41 > 3 > 305-308

Some unidentified minor compounds have been observed in the residue from short-path distillation of transesterified palm oil that are not detected in the original palm oil. A method combining short-path distillation to enrich the unknowns with fractionation using solid-phase extraction is described. The fractionated components were identified using GC coupled with MS. The transesterified palm oil...

article

Quality of residual oil from palm-pressed mesocarp fiber (Elaeis guineensis) using supercritical CO₂ with and without ethanol

Harrison Lik Nang Lau, Yuen May Choo, Ah Ngan Ma, Cheng Hock Chuah

Journal of the American Oil Chemists' Society > 2006 > 83 > 10 > 893-898

The qualities of oils extracted from fresh and dried palm-pressed mesocarp fiber were evaluated. The means of extraction included conventional solvent extraction and supercritical carbon dioxide (SC-CO₂) extraction with and without addition of ethanol. Extraction efficiency using pure SC-CO₂ and the effect of moisture content on efficiency were studied. Minor components, such as vitamin F, carotenoids,...

article

Simultaneous quantification of free fatty acids, free sterols, squalene, and acylglycerol molecular species in palm oil by high-temperature gas chromatography-flame ionization detection

Harrison Lik Nang Lau, Chiew Wei Puah, Yuen May Choo, Ah Ngan Ma, more

Lipids > 2005 > 40 > 5 > 523-528

This paper discusses a rapid GC-FID technique for the simultaneous quantitative analysis of FFA, MAG, DAG, TAG, sterols, and squalene in vegetable oils, with special reference to palm oil. The FFA content determined had a lower SE compared with a conventional titrimetric method. Squalene and individual sterols, consisting of β-sitosterol, stigmasterol, campesterol, and cholesterol, were accurately...

article

Application of supercritical fluid chromatography in the quantitative analysis of minor components (carotenes, vitamin E, sterols, and squalene) from palm oil

Yuen May Choo, Mei Han Ng, Ah Ngan Ma, Cheng Hock Chuah, more

Lipids > 2005 > 40 > 4 > 429-432

The application of supercritical fluid chromatography (SFC) coupled with a UV variable-wavelength detector to isolate the minor components (carotenes, vitamin E, sterols, and squalene) in crude palm oil (CPO) and the residual oil from palm-pressed fiber is reported. SFC is a good technique for the isolation and analysis of these compounds from the sources mentioned. The carotenes, vitamin E, sterols,...

article

Rapid synthesis of palm-based monoacylglycerols

Sit-Foon Cheng, Yuen-May Choo, Ah-Ngan Ma, Cheng-Hock Chuah

Journal of the American Oil Chemists' Society > 2005 > 82 > 11 > 791-795

Rapid synthesis of high-purity MAG from refined, bleached, and deodorized palm stearin (RBDPS) via chemical glycerolysis in the presence of pyridine was developed to obviate the conventional molecular distillation in the production of pure MAG. The optimal reaction for the sodium methoxide-catalyzed glycerolyis of RBDPS was recorded at 110°C using a 3 wt% catalyst concentration based on the weight...

article

Separation of vitamin E (tocopherol, tocotrienol, and tocomonoenol) in palm oil

Mei Han Ng, Yuen May Choo, Ah Ngan Ma, Cheng Hock Chuah, more

Lipids > 2004 > 39 > 10 > 1031-1035

Previous reports showed that vitamin E in palm oil consists of various isomers of tocopherols and tocotrienols [α-tocopherol (α−T), α-tocotrienol, γ-tocopherol, γ-tocotrienol, and δ-tocotrienol), and this is normally analyzed using silica column HPLC with fluorescence detection. In this study, an HPLC-fluorescence method using a C₃₀ silica stationary phase was developed to separate and analyze the...

article

Phospholipids from palm-pressed fiber

Yuen May Choo, Siow Ching Bong, Ah Ngan Ma, Cheng Hock Chuah

Journal of the American Oil Chemists' Society > 2004 > 81 > 5 > 471-475

Palm-pressed fiber, a by-product of palm oil milling, was extracted successively with hexane and 95% ethanol; the ethanol extracts yielded 46,800 ppm of phospholipids. The phospholipid composition, as analyzed by HPLC coupled with an ELSD, was found to be predominantly PC, PE, phosphatidylglycerol, and PA; as expected, the FA were more unsaturated than the TAG. Palm-pressed fiber is estimated to be...

INFONA - science communication portal

Search results for: Ah Ngan Ma

Determination of Coenzyme Q₉ and Q₁₀ in Developing Palm Fruits

Selective extraction of palm carotene and vitamin E from fresh palm-pressed mesocarp fiber (Elaeis guineensis) using supercritical CO2

Very long chain fatty acid methyl esters in transesterified palm oil

Quality of residual oil from palm-pressed mesocarp fiber (Elaeis guineensis) using supercritical CO₂ with and without ethanol

Simultaneous quantification of free fatty acids, free sterols, squalene, and acylglycerol molecular species in palm oil by high-temperature gas chromatography-flame ionization detection

Application of supercritical fluid chromatography in the quantitative analysis of minor components (carotenes, vitamin E, sterols, and squalene) from palm oil

Rapid synthesis of palm-based monoacylglycerols

Separation of vitamin E (tocopherol, tocotrienol, and tocomonoenol) in palm oil

Phospholipids from palm-pressed fiber

Filter options

Publication date

Keywords

Data set

Journal

INFONA - science communication portal

Search results for: Ah Ngan Ma

Add recipient

Sending message cancelled

Are you sure you want to cancel sending this message?

Send message

Filter options

Publication date

Date range setting

Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.

Keywords

Data set

Journal

Reporting an error / abuse

Sending the report failed

Accessibility options