Category Archives: In Press

STUDIES OF BUNCH ANALYSIS 2 – BUNCH SAMPLING TO ESTIMATE OIL YIELD

To estimate oil yield in research trials, fresh fruit bunch (FFB) yield is multiplied by the oil/bunch determined on a sample of bunches, but there is no standard method for sampling bunches. Data from palms in which all bunches were analysed for seven years allowed actual mean oil/bunch (O/B) and oil yields to be calculated, and compared with estimates from samples. Samples of five bunches per palm gave poor precision, with 95% confidence limits of about ± 4% O/B. Increasing the number of bunches to 10 per palm gave confidence limits of about ± 2.5% O/B. Alternatives include analysing more bunches only if the coefficient of variation (CV) for five bunches is large, or measuring fruit/bunch and oil / mesocarp on 10 bunches, and mesocarp / fruit, which is less variable, on only two or three bunches. The mean O/B of five bunches may give acceptable estimates of oil yield per palm. For progeny or treatment mean oil yields, the mean of 50 bunches per progeny gives a CV of about 10%. Precision is increased if a bunch is sampled from every palm, rather than at random from the progeny. When considering mechanisation of bunch analysis, a method in which the bunch components are determined on different bunches has no disadvantages.

STUDIES OF BUNCH ANALYSIS 1 – VARIATION WITHIN AND BETWEEN PALMS

There is little information on variation in composition between different bunches from the same palm. In this study, bunch analysis was done on all bunches from three plots of 20 palms, over seven years. There were significant differences between palms for all bunch components. Palm means for oil/bunch were correlated with fruit/bunch and oil/mesocarp, and less strongly with mesocarp/fruit. A previously unreported correlation between palm means for fruit/bunch and oil/dry mesocarp was found; this appeared to be a genetic effect, as there was no such correlation within palms. There was also a correlation between palm means for fresh fruit bunch (FFB) yield and oil/dry mesocarp. Between bunches within palms, the most variable bunch component was fruit/bunch; for this and for oil/mesocarp the within-palm component of variance was much larger than the between-palms component. For fruit composition (mesocarp, kernel and shell/fruit), the between-palm variance was larger. Within palms, mesocarp/fruit tended to be negatively correlated with fruit/bunch. Shell/fruit was significantly correlated with kernel/fruit in most tenera palms, but not in most duras.

ISOLATION AND CHARACTERISATION OF AN ETHYLENE RECEPTOR (ERS-TYPE) FROM OIL PALM (Elaeis guineensis Jacq.) MESOCARP

The oil palm (Elaeis guineensis Jacq.) fruit is climacteric whereby ripening process of the fruits is accompanied by a burst of ethylene production. Hence, to understand the underlying molecular mechanisms and the role of ethylene in the ripening process of oil palm fruits, this study focused on the isolation and characterisation of the ethylene receptor gene, the first component in the ethylene signalling pathway. The full-length cDNA is 2225 kb long and encodes a polypeptide of 629 amino acid residues. Sequence analysis showed it has conserved domains and a protein structure similar to the ERS-type ethylene receptors found in ethylene receptor genes from other plant species. Northern and Southern analyses revealed that it is highly expressed in the mesocarp tissues and that this gene exists as multiple copies in the oil palm genome. These results provide evidence that oil palm fruit development is regulated by ethylene through the action of the EGER D3 ethylene receptor gene, which opens up the possibility of manipulating the ethylene receptor to control ethylene sensitivity during oil palm fruit development to help further improve oil palm yields.

AUTOMATIC CRUDE OIL DILUTION CONTROL WITH PREMIUM OIL SEGREGATION USING NEAR INFRARED (NIR) ON-LINE SYSTEM

The clarification operation in a palm oil mill is an important processing step that should be carefully handled with as much care as possible. As the oil loss in the clarification processes is a major source of oil loss in the overall milling operation, there is an urgent need to improve the crude oil dilution control for efficient oil recovery. Currently, there are no reliable methods to maintain the oil to crude oil ratio. As a result, no automatic dilution control is in practice even when mill throughputs are widely fluctuating. The trend to produce crude palm oil with low (<1.5%) free fatty acid (FFA) appears to be increasing among the millers as it commands a premium price in the world markets. In order to meet this demand, it will be worthwhile to use the near infrared (NIR) analyser for rapid analysis of the crude oil. It is also more efficient than the conventional method. Field trial results have shown that the NIR On-line system can be used not only to control the water dilution at an average of 39% to 40% of the crude oil but also to monitor the FFA content below 1.5% for automatic premium oil segregation during the palm oil processing.

DETERMINATION OF TOTAL PHENOL, FLAVONOID, ANTIOXIDANT ACTIVITY OF OIL PALM LEAVES EXTRACTS AND THEIR APPLICATION IN TRANSPARENT SOAP

Oil palm leaves (OPAL) extract is gaining considerable interest as it is derived from a natural source and provides many functions such as anti-microbial effect towards bacteria, good ultraviolet (UV) protection and possesses the ability to combat several skin diseases due to its antioxidant properties. In this study, the phenolic compounds from OPAL extracted via four different extraction procedures i.e. extraction with ethanol (OPAL M1), extraction with hexane and followed by ethanol (OPAL M2), extraction with hexane and with ethanolic hydrochloric acid (OPAL M3) and aqueous extraction (OPAL M4) were studied. Total phenolic content (TPC) and total flavonoid content (TFC) of the OPAL extracts were determined and their antioxidant activity compared with butylated hydroxytoluene (BHT). The results indicated that OPAL M1 and OPAL M2 had higher TPC and TFC than OPAL M3 and OPAL M4. All OPAL extracts showed antioxidant activities similar to BHT but required a higher concentration. The transparency and brightness of the transparent soaps formulated with OPAL extract were not affected at 0.1% concentration. Thus, OPAL extracts have the potential to be used as natural antioxidant and colourant in transparent soaps.