Category Archives: 1995 Vol 7 No 2

The influence of low temperature treatment on growth and proline accumulation in polyembryogenic cultures of oil palm (Elaeis guineensis Jacq.)

Low temperatures (15ºC-20ºC) were observed to inhibit the growth and multiplication of oil palm polyembryogenic (PE) cultures. These conditions enable PE cultures to be kept for at least six months without subculturing. The method can, therefore be exploited for minimal growth storage of in vitro cultures. Proline, which is known to be a universal stress indicator, was found to accumulate in the cultures under low temperature stress and the increase was about two-fold during 30 days of exposure. In the presence of 0.5 M sucrose, low temperature storage of cultures could be extended even to nine months.

Isolation and identification of bacteria associated with Elaeidobius kamerunicus and oil palm flowers

A study was carried out to isolate and identify Gram-negative bacteria associated with the larvae of Elaeidobius kamerunicus and male oil palm spikelets. Nine species of floral bacteria and seven species of larval bacteria were identified. They belong to four genera, namely Enterobacter, Serratia, Klebsiella and Escherichia. Most of the bacteria isolated from larvae were also found in both the soil and male spikelets. Two predominant species of entomopathogenic bacteria isolated from the weevils and spikelets were Enterobacter cloacae and Serratia marcescens. Often, the same species of bacteria isolated from the weevil’s haemocoel were also found in the intestine. The frequenceis of isolation were 17%, 12% and 5% for samples collected from oil palm plantations at Banting, Labuan and Serdang respectively.

Cytological analysis of Elaeis guineensis (tenera) chromosomes

Cytological analyses were performed on chromosomes of the oil palm Elaeis guineensis of the tenera fruit phenotype using metaphase chromosome spreads. Root tips were obtained from three to four weeks old seedlings and pretreated with 2mM 8-hydroxyquinoline for 5-6 hours at 18 degrees C to increase the metaphase index. Using a protoplast technique, chromosome spreads free of cell wall and cytoplasmic debris were obtained. Cytological analysis on six metaphase spreads showed that oil palm contains 2n = 32 chromosomes and paired t-tests performed showed no significant difference between homologues for chromosome pairs Nos. 1-5, 7, 8, 10 and 12-16, whereas chromosome pairs Nos. 6, 9 and 11 showed significant differences between members. Significant differences may be caused by varying degrees of chromosome condensation between spreads and slide preparations, and also errors incurred during measurement. Based on length, chromosome pair No. 1 was assigned to group I, Nos. 2-9 were assigned to group II and Nos. 10-16 to group III. Group I consists of the longest chromosome (10.83% of total chromosome length), group II of medium length chromosomes (6.21%-8.42% of total chromosome length) and group III of medium short chromosomes (3.17%-5.37% of total chromosome length).

Preparation of palm-based esteramines using chemical catalysts

The reaction of fatty acids or of fatty esters with triethanolamine in the presence of an acid or a base, results in the formation of fatty esteramines. In the present work the effects of using various mole ratios of palm and tallow based fatty acids and amounts of catalyst were studied, as well as the reaction products in the presence and absence of solvent.

Preparation of hard butter from palm and sal ‘olein mixture’

Olein mixtures {[POo:SLo]} obtained from the acetone fractionation (at 10°C) of palm olein (POo) and sal fat (SL) blends {[POo:SL(70:30)]o, [POo:SL(55:45)]o, and [POo:SL(40:60)]o} were hydrogenated at: temperature, 200°C; pressure, 7 psi; and stirring rate, 500 rpm, using 0.1% catalyst (Nysel SP-7, G-15 Flakes or Resan-22). The physicochemical changes in the olein mixtures during hydrogenation were studied by determining their slip melting points, iodine values, hardness and DSC melting curves. These studies revealed that the use of [POo:SL(70:30)]o, Nysel SP-7 catalyst and a hydrogenation time between 1.0 and 1.5 hr was suitable for the preparation of cocoa butter substitute.

Vegetable oil in aqueous and nonaqueous microemulsion systems stabilized by nonionic surfactants

Nonionic microemulsions with a palm oil-based emollient, i.e. medium chain triglyceride, MCT, stabilized by two nonionic surfactants were investigated in both aqueous and nonaqueous (glycerol and formamide) systems. The results showed the presence of aqueous (or non-aqueous)-in-MCT microemulsions in all the systems investigated. MCT-in-aqueous (or nonaqueous) microemulsions were also observed except the glycerol system. In addition, the results also indicated that the solubilization behaviour encountered in the aqueous and nonaqueous systems investigated was dependent on the surfactant ratio.

Densities and refractive indices of hydrogenated palm olein and fractionated palm oil

The densities and the refractive indices of seven samples of neutralized, hydrogenated palm olein and six fractions from palm oil were determined. It was found that both the density and the refractive index decreased linearly with increasing temperature over the range 30°C to 80°C. The temperature coefficients for these properties were determined for both groups of samples. These properties were also found to be linearly dependent on iodine values. Equations were developed for the two properties for each group of samples. These equations accurately predict the densities and the refractive indices for all the samples at the temperatures studied.

Characterization of a by-product of palm oil milling

The characteristics of sludge palm oil, a by-product of the palm oil milling process, were analyzed using six quality parameters for oils and fats. Volatile analyses namely headspace gas chromatography and simultaneous distillation-extraction, were also carried out to help characterize the oil. Results from the ‘six parameter’ determinations showed that the oil had on average a moisture content of 0.99%, free fatty acid 44.43% (as palmitic acid), peroxide value 9.98, iodine value 49.81, saponification value 197.47 and unsaponifiable matter 0.350 per cent. The headspace gas distillation extract showed the presence of aldehydes, ketones, alkanes, furan, phenols, carboxylic acids and esters.