Category Archives: 2007 Vol 19 June

Potential of utilizing rhinoceros beetles (Oryctes rhinoceros) as an ornamental fish feed supplement

Oryctes rhinoceros adult beetles which are commonly trapped in pheromone traps in oil palm plantations can be used as a supplement for ornamental fish feed. Oryctes beetles were ground into powder and were incorporated with wheat, rice and fish feed formula. Initial feeding experiments using Oryctes powder + wheat and rice were conducted on several species of ornamental fishes such as puyu, Anabas testudineus; gold fish, Carassius auratus auratus; common carp, Cyprinus carpio carpio and oscar, Astronotus ocellatus. A final experiment using Oryctes powder as a supplement to a fish feed formula was tested on gold fish, carp, parrot fish (Cichlasoma) and common gourami (Osphronemus goramy). In this study, the Oryctes powder seem to be suitable for gold fish and carp on wheat mixtures. This article highlights the potential of using Oryctes powder as a supplement to the fish feed formula. The evaluation of the Oryctes supplemented pellets in comparison with other commercial types of fish feed are also discussed.

Application of powder formulation of Metarhizium anisopliae to control Oryctes rhineceros in rotting oil palm residues under leguminous cover crops

The powder formulation of Metarhizium anisopliae was applied by spraying method onto the rotting heaps of oil palm residues under the leguminous cover crops. The M. anisopliae infected all stages of Oryctes rhinoceros. At eight months after treatment (MAT), the application of product at rates of T1, 0.2 g (2.2 x 107 spores) and T2, 0.4 g (4.4 x 107 spores) m-2 heap was significantly reduced (P<0.05) the L2 and L3 larvae, pre-pupae and pupae. Reduction of these four stages has reduced the overall O. rhinoceros population in T1 to 30.8 individual per sampling plot (ISP) and T2 to 41.0 ISP, significant lower (P<0.05) as compared to population in the control (132.1 ISP).

The growing of cover crops delayed the impact time of the fungus, but it provided protection to the fungus from the detrimental factors, giving favourable conditions to the spores to grow and initiate infection. Therefore, at eight MAT, as the population was significantly reduced, the infection levels were increased to 33.3% in T1 and 30.4% in T2, both were significantly higher (P<0.05) as compared to control (12.9%). Then it was further increased to 52.0% (control), 67.8% (T1) and 72.9% (T2) at 12 MAT. The use of the product at both rates did not affect the non-target insects. The oil palm pollinating weevil, Elaeidobius kamerunicus was not affected as they was no difference in the population density in the treated and control plots. The population density of the stag beetle, Aegus chelifer in both treated plots was always not significant (P>0.05) with the control at all times of data recording. Although infection can occur on larvae and adults, but the percentage was low, ranging from 0% – 0.6% at five MAT and 1.7% and 2.5% at eight MAT.

Synergistic effect between sodium lauryl sulphate and sodium lauryl ether sulphate with alkyl polyglycoside

The performance of two palm-based anionic surfactants, sodium lauryl sulphate (SLS) and sodium lauryl ether sulphate (SLES), and a non-ionic surfactant, alkyl polyglycoside (APG) was studied. The parameters measured were critical micelle concentration, surface tension, detergency and foaming. The combination of both SLS:APG and SLES:APG both at ratio 6:4, achieved the lowest surface tension compared to SLS and SLES alone. Subsequently, the best detergency was also found at the same ratio for the SLS:APG and SLES:APG systems. These surfactant mixtures also enhanced the foam volume and stability

The effect of pp/mapp blends on EFB fibres for improving tensile and dimensional stability properties

Empty fruit bunch fibre – polypropylene composites with treated and untreated maleated polypropylene (MAPP) were produced. The MAPP used as coupling agents were Epolene-43 (commercial MAPP) and MAPP samples produced in laboratory. Analyses on the MAPP samples included FTIR, acid number and grafting degree (Gd) to determine the number of anhydride groups available in the MAPP. The MAPP-treated composites had better tensile results than the untreated ones. The dimensional stability of the MAPP- treated samples improved with water absorption and as the thickness swelling decreased. The scanning electron microscopy (SEM) of the interfacial regions between filler and matrix showed the treated composites to have better interaction than the untreated samples.

Characterization of estolides from dihydroxystearic acid

Dihydroxystearic acid estolides (DHSA-estolides) were produced by intermolecular esterification between the hydroxyl group and carboxyl group in dihydroxystearic acid (DHSA). The products obtained were characterized by Fourier transform infrared (FTIR), proton and carbon nuclear magnetic resonance spectroscopy (1H-NMR, 13C-NMR). The appearance of two ester peaks at 1734 cm-1and 1740 cm-1 wavenumber revealed the formation of DHSA-estolides. The ester methine signal at 4.84 ppm was an indication of an estolide linkage in the 1H-NMR spectrum while the 13C-NMR showed two carbonyl signals at 178.78 ppm for acid and 172.08 ppm for estolide. Titration of carboxylic acid with a standardized base was used to determine the average molecular weights of the estolides as well as their estolide numbers (EN).

Adsorption isotherms for removal of iron, copper, phosphorus and oxidation products from crude palm oil using natural and acid-activated clays

A study was carried out on acid activated clay (W) and non-acid activated clays (P and A). Trace metal components and phosphorus compounds were monitored. The Langmuir isotherm was more applicable than the Freundlich isotherm for the adsorption of trace metals, copper and iron. Both the non-acid activated clays were better adsorbents of iron from degummed and bleached palm oil than the acid-activated clay, indicating that neutral and natural adsorbents (clays P and A) could be better for removal of iron in crude palm oil than the acid activated clay in spite of having lower surface areas. Clay P was the best adsorbent for most of the analysed components among the three tested clays. The degummed palm oil bleached with clay P had the lowest concentrations of phosphorus and copper. The removal of primary and secondary oxidation products did not follow the Freudlich and Langmuir equations, probably due to changing values effected by the adsorbent rather than by just mere adsorption.
The study shows that careful selection of clays for specific functions is very important for bleaching efficiency where minor impurities in palm oil are removed.

Short-term responses of oil palm to an interrupted dry season in North Kedah, Malaysia

The annual dry season in north Kedah, which can extend for two to three months, was interrupted in 2006 by three substantial rains at approximately monthly intervals. Measurements of CO2 , latent heat and sensible heat fluxes above the canopy of five and a half year-old oil palm, supplemented by growth measurements, soil water and supporting meteorological data, indicated considerable mitigation by the rainfall of the effects of the dry season. Thus, reductions in CO2 uptake, canopy conductance and evapotranspiration, and increases in sensible heat flux and accumulation of spear leaves, were less than expected.
The data suggest that even infrequent irrigation during a dry season may suffice to prevent a substantial build-up of stress in the palms under the edaphic conditions of the trial. Further observations to determine the long-term impacts on yield are, however, necessary.

Optimization of degumming with attapulgite and acid-activated clays in refining palm oil

Attapulgite clay was evaluated as adsorbent in palm oil refining with different dosages of degumming agent (phosphoric acid). Its adsorption of trace metals (iron and phosphorus), chlorophyll pigment and primary and secondary oxidation products, was compared with that by a commercial bleaching clay. Attapulgite clay showed its potential as adsorbent for refining palm oil. Commercial acid-activated clay W and attapulgite clay A responded differently to increase concentration of phosphoric acid during degumming. There was a direct correlation between the iron content and concentration of phosphoric acid. The results of the study are relevant to the earths with the properties shown in this paper and may differ from those of other clays. It is clear from the study that the efficiency of adsorption maybe not necessarily be related to the acid activation of the clay.