Category Archives: 1997 Vol 9 No 2

Identification of palm oil and its fractions by HPLC using triacylglycerol peak-area ratios

The concept of peak-area ratios in reversed-phase HPLC of triacylglycerols in palm oil and palm oil fractions was expanded and tested by analysis of numerous authentic samples. Palm oil fractionation changes the tripalmitin and triolein peaks and peak-area ratios. To expand the database, a large number of palm oils, palm oleins and palm stearins of Malaysian origin were investigated and the results compiled. Variability of the peak areas and peak-area ratios with changes of solvents is discussed. Peak-area ratios were found to be useful in identifying palm oils from different sources as well as in detecting possible admixtures of oils.

Synthesis and characterization of the monoethanolamide from palm oil

Palm monoethanolamide (PMEA) was synthesized by direct transamidation of palm oil with monoethanolamine of temperatures between 80-160°C. The maximum yield (85.5%) was achieved at a palm oil/monoethanolamine mole ratio of 1:3, temperature of 160°C, reaction time of 3 hours and catalyst concentration of 0.6%. Recrystallization using a combination of hot hexane and warm water were the best conditions to purify the PMEA, as judged by its melting point and infrared (IR) spectrum. The PMEA was not soluble in water and most hydrocarbon solvents. However, about 60% of it dissolved in a microemulsion system containing 25% water at 50°C. The transamidation process proceeded via a first order reaction with an activation energy of 17.4kJ/mol

Analysis of oil palm productivity. I. The estimation of seasonal trends in bunch dry matter production

When assesing oil palm productivity over periods of less than a year, the direct use of bunch harvest data, normally available as monthly totals of FFB yield is inadequate as much of the dry matter in a bunch may be formed prior to the month of harvest. Also, as is widely recognized, the higher energy content of bunches compared with vegetative tissue needs to be allowed for. To take account of these factors, a simple model was constructed based on monthly FFB yields, final bunch composition, growth curves of bunch components and component energy contents, to allow the bunch ‘non-oil equivalent’ dry matter production (BDMP) achieved each month to be calculated. The model was applied to data from two sites over several seasons. BDMP estimates from the model showed similar, but displaced, cyclic patterns to FFB, and gave smoother curves with lower CVs. Although based on a fixed bunch growth rate throughout the year, the results proved insensitive to growth duration and were similar for growth periods ranging from 130 to 190 days.

Analysis of oil palm productivity. II. Biomass, distribution, productivity and turnover of the root system

As part of a programme investigating the productivity of oil palms in West Malaysia, measurements were made of root standing biomass in two successive years at each of six sites. Palms at the first two sites were sampled three to four years after planting and the others at nine and ten years. One site was on a ‘coastal’ soil while the others were on ‘inland’ soils of various series. In two cases, direct comparisons were made of adjacent ‘wet’ and ‘dry’ areas.

On each site detailed measurements were also made of above-ground standing biomass and productivity. On each site root-free soil cores were ‘installed’ and sampled for roots after a six month period, allowing an assessment of new root production and providing a measure of root biomass turnover. An alternative estimate of root turnover was obtained for the coastal site using a carbon balance approach.

Ratios between root:shoot standing biomass and the proportion of total assimilates allocated to the shoot versus the root system are presented for each site.

Results are discussed in relation to those of other studies of oil palm root biomass.

Proline accumulation in the leaves of water stressed oil palm (Elaeis guineensis Jacq.) seedlings

An increase in stomatal resistance of oil palm seedlings was related to increasing water deficit indicated by a reduction in leaf water potential. Proline began to accumulate after stomatal resistance reached a peak (215.6±16.8 s cm-1). This led to a recovery in leaf water potential followed by a similar reduction in stomatal resistance. The proline level eventually fell to the control level after watering was resumed. Water stress also reduced dry matter production and its partitioning to the root system of oil palm seedlings.

Preparation of biodegradable and vegetable based surfactant from sugar and palm fatty acid catalyzed by Mucor miehei lipase

Sugar ester was prepared from palm fatty acid distillate (PFAD) with Lipozyme IM (immobilized Mucor miehei) as catalyst. Four sugars were used, sucrose, sucrose octaacetate, glucose and fructose. Fructose was esterified by PFAD to produce 17.70 mg/ml solvent of product while glucose produced 13 mg/ml solvent. It was found that a mol ratio of fructose/PFAD of 1/10, 10% lipase concentration and a temperature of 55°C gave the highest yield. Analyses of its physical and chemical properties showed that fructose ester had a melting point of 49°C to 52.3 °C. The surfactant, a fructose ester, also reduced the surface tension of water from 74 dyne/cm to 38.3 dyne/cm. Eventhough the yield was still quite low compared to what had previously been obtained using other substrates, this study showed that enzymatic preparation of surfactant from PFAD is possible