Category Archives: 2006 Vol 18 June

Household usage of and recipe creation with condiment sauces based on red palm oil : exploring the potential for targeted micronutrient delivery to different family members

Combining foods that are naturally rich in essential micronutrients with other foods commonly used in the diets of low income households (food-to-food fortification) can be a sustainable way to deliver micronutrients. Properly conceived, the nutrients can be selectively targeted to different generations within the family. In a convenience sample of Guatemalan women, the feasibility of this approach using red palm oil (RPO, Carotino® ), a food with extraordinary high pro-vitamin A carotenoids of up to 0.08% (w/w) of the crude oil, tocopherols and tocotrienols, was explored. Dishes were prepared with RPO as both red tomato and hot green sauces. Both had high acceptability to rural and urban low income women. Two hundred forty-five grammes of red tomato sauce and hot green sauce were distributed free. The women prepared many dishes with the red tomato sauce, but only five with the hot green sauce, which was instead mostly used as a garnish. We concluded that oils added to condiment sauces can enhance the nutrient contents in foods on the family table, and selective direction to adult members is feasible. More nutrient-rich oil will deliver more nutrients in this food-to-food fortification with RPO.

Identification of lutein in crude palm oil and evaluation of carotenoids at various ripening stages of the oil palm fruit

The xanthophylls in crude palm oil (CPO) were identified as lutein, α-carotene 5,6-epoxide, α-carotene 5,8-epoxide, and β-carotene 5,6-epoxide and/or β-carotene 5’,6’-epoxide based on their electronic absorption maxima from HPLC-PDA. Lutein, a dihydroxy carotenoid, was isolated from CPO extract and its structure confirmed by co-elution with an authentic standard using HPLC-photodiode array (PDA) and mass spectra. At 7 DAA (days after anthesis), lutein was predominant with only trace amounts of α- and β-carotenes. At 21, 84 and 126 DAA, the levels of α- and β-carotenes increased although lutein still predominated. However, when the palm fruit ripens at 140 DAA, the level of lutein decreased dramatically to a minor carotene while α- and β-carotenes predominated with other minor carotenes, i.e. phytoene, lycopene, β-zeacarotene, γ-carotene, ζ-carotene, formed.

Production of moulded palm-based flexible polyurethane foams

In our previous study, incorporation of phthalates in slab stock flexible foam formulation improved the properties of the foams. This paper describes the properties of moulded flexible foams which incorporated phthalate alone, and with two other additives. Flexible foam from blended polyols (50:50 ratio palm-based to polyether polyols) was also produced, by the best formulation selected from the above. The properties evaluated were density, tearstrength, compressive stress and hysteresis. The results were compared to those from the commercial seating cushions. The flexible foams from total palm-based polyol had tear strength of 140-150 N m-1 , and, therefore can only be used in automotive parts such as carpet underlay and thermal insulator. Better foams were produced from blended polyols (50:50 palm-based to petrochemical polyether polyols) with the tear strength approaching those of commercial foams and improved resilience. More improvements to the properties are expected when a high dispensing machine is used in the manufacturing.

Nutrients demands of tenera oil palm planted on inland soils of Malaysia

Oil palm is unrivalled in its ability to convert solar energy into dry matter and vegetable (palm) oil. This process requires a large amount of nutrients, which must be supplied through soil or fertilizers. Good nutrient management, which includes a site-specific nutrient management plan, is important to achieve high yields of palm oil. Good knowledge of nutrient requirements at the various stages of growth and development of the oil palm is needed for the nutrient management plan and greater fertilizer-use efficiency. This paper highlights the nutrient requirements of oil palm based on the nutrient contents of tenera palms from analysis of their nutrients in fresh fruit bunches (FFB), trunk and roots in a 32 NK x 2P factorial fertilizer trial on Bungor series soil. The results showed that more of N is actually removed than previously estimated but an annual application of 4.2 kg ammonium sulphate per palm meets the nutrient demands to produce 30 t FFB ha-1 , i.e., the N applied balances the N demand. However, the K applied was surplus (23% of the 3.5 kg potassium chloride per palm applied) to the actual requirement of the palms. The unaccounted P (surplus of 20%) could have been fixed by the soil, which suggests that more phosphate rock fertilizer, i.e. over 2 kg palm-1 yr-1 , is required to compensate for the P immobilized by the soil. The paper also proposes a comprehensive and sound nutrient management plan comprising various complementary components.

Thermochemical behaviour of empty fruit bunches and oil palm shell waste in a circulating fluidized-bed combustor (CFBC)

Circulating fluidized-bed (CFB) technology is considered to be one of the most suitable techniques to thermally convert fuels into useful energy. However, practical experience is available for only a limited number of fuels and conditions. This paper describes the results from a bench-scale circulating fluidized-bed combustor (CFBC), installed at SIRIM Berhad, Shah Alam, for gasification and combustion of different biomass materials. The purpose of the tests was to investigate the suitability of the selected fuels for energy production using CFBC while taking care of the flue gas emissions. The experiments gave sufficient information on the main process and flue gas characteristics. The measurements for temperatures and emissions were done for four different biomass samples of empty fruit bunch (EFB) of palm shell and palm shell waste powders of 210-300, 425 and 600 microns. The concentrations of CO, NOx and CO2 in the flue gas were measured continuously. The combustion performances were evaluated by varying the primary gas flow through the CFBC tubular furnace to identify the optimum operating conditions for the CFBC. The NOx content was from 20-164 ppm while the CO emissions were high for some operating conditions.

DNA extraction from mature oil palm leaves

Molecular markers have a useful role in oil palm improvement as conventional breeding is limited by the large size of the palm and its long generation interval. The starting point for such applications is DNA extraction using young, immature leaves as required by common protocols. Since such leaves are sometimes not available or are difficult to obtain, a modified method of DNA extraction from older, more mature oil palm leaves kept for a period of time, has been developed. Key changes were initial extraction at ice-cool temperatures and modification of the standard buffers. The DNA obtained by this method was fully digestible for AFLP assay.

Assessment of aquatic effects of palm-based alpha-sulphonated methyl ester (SME)

The toxicities of palm-based alpha-sulphonated methyl esters (SME) produced in MPOB’s SME pilot plant were consistent throughout the production period, i.e.around 1.00-1.41 mg litre-1 . Its toxicity was comparable to two palm-based commercial SMEs whether tested in temperate or tropical environment. The surfactants were found to be less toxic when tested under tropical conditions. The toxicity is related to the carbon chain length of methyl esters used to produce SME. Higher carbon chain length will cause an increase in the toxicity of anionic surfactant as seen in palm-based SME (C16/18) and commercial SME 1 (C16/18). Commercial SME 2 (C14/16) was slightly less toxic due to the lower carbon chain length. Their toxicities, however, were still within the same toxicity range, i.e. moderately toxic. Palm-based SME is not expected to cause environmental concern due to only 10% – 30% of it is used in detergent products, its biodegradability was more than 80% in only eight days and the dilution in aquatic environment will cause the local predicted environmental concentration to be very low. The use of palm-based SME will help to stimulate Malaysia’s agricultural economies and lessen our dependence on imported petroleum-based surfactants.

Alkanolamides from 9,10-Dihydroxystearic acid

Alkanolamides of dihydroxystearic acid (DHSA-alkanolamides) have been synthesized. The factors that may affect their esterification, such as reaction time and temperature, were studied. Given the same time course, ethanolamine gave higher yield due to its shorter carbon chain compared to that of propanolamine. The products were identified by Fourier transform infrared spectroscopy, gas chromatography as well as nuclear magnetic resonance spectroscopy. From the gas chromatography, DHSA-ethanolamide and DHSA-propanolamide were detected at retention times of 15.62 min and 16.61 min, respectively. These compounds were found to be non-irritants to the skin and biodegraded more than 60% in 20 days.

Viability of using a one-dimensional lovibond scale for colour measurement of palm oil and palm oil poil products

A one-dimensional Lovibond scale for measuring colour required fixing the yellow numeral in some functional relation to the red. The colour of a sufficiently large number of palm oil and palm oil products was measured using the conventional Lovibond scale. The colour of the same samples was then measured by fixing the yellow units at pre-determined values but varying the red values to get the closest colour match. The fixed yellow unit for each type of palm oil and palm oil products was determined by reading the colour of the oils at fixed yellow units of 25, 30, 35 and 40 with independent variation of the red units. Four analysts from two different laboratories were involved in the colour measurements. The readings obtained were then analysed to determine the yellow value that gave the best colour match. Statistical evaluation showed that the colour values obtained using the one-dimensional Lovibond colour scale did not differ from the results using the conventional scale. Nevertheless, the investigation indicated that the results of palm oil and palm olein colour obtained by analysts from different laboratories using the former method were more comparable than that of the latter. As this was not observed in measurements for palm stearin, the recommendation is therefore for the retention of the conventional method of colour measurement.

Recovery and conversion of palm olein-derived used frying oil to methyl esters for biodiesel

Frying oils (both vegetable oils and animal fats) degrade with use, and beyond the limits, the excessive free fatty acids (FFA), peroxide value (PV) and polar components preclude their further use in food applications, unless they can be purified by very effective adsorbent systems. In this study, four adsorbents: silica gel, activated carbon, aluminium oxide and acid-activated spent bleaching earth were used to reduce some of the poor quality parameters of the oils. Although pre-treatment of used frying oils with these adsorbents could improve the oil quality to a certain extent, the oils could only be used for non-food applications. The FFA and PV of the treated oils subjected to the above adsorbent treatment, were reduced as follows: 33.3% and 65.1%, 6.5% and 7.8%, 30.2% and 20.8%, and 11.8% and 46.9% respectively, and silica gel was found to be the most effective adsorbent. The treated used frying oil was converted into methyl esters as biodiesel. The methyl esters obtained had comparable fuel properties as petroleum diesel. Hence, it can be used as a diesel substitute.