RBD Palm Stearin Research Articles

Stability evaluation of quality parameters for palm oil products at low temperature storage.

Palm oil is one of the major oils and fats produced and traded worldwide. The value of palm oil products is mainly influenced by their quality. According to ISO 17025:2005, accredited laboratories require a quality control procedure with respect to monitoring the validity of tests for determination of quality parameters. This includes the regular use of internal quality control using secondary reference materials. Unfortunately, palm oil reference materials are not currently available. To establish internal quality control samples, the stability of quality parameters needs to be evaluated. In the present study, the stability of quality parameters for palm oil products was examined over 10 months at low temperature storage (6 ± 2 °C). The palm oil products tested included crude palm oil (CPO); refined, bleached and deodorized (RBD) palm oil (RBDPO); RBD palm olein (RBDPOo); and RBD palm stearin (RBDPS). The quality parameters of the oils [i.e. moisture content, free fatty acid content (FFA), iodine value (IV), fatty acids composition (FAC) and slip melting point (SMP)] were determined prior to and throughout the storage period. The moisture, FFA, IV, FAC and SMP for palm oil products changed significantly (P < 0.05), whereas the moisture content for CPO, IV for RBDPO and RBDPOo, stearic acid composition for CPO and linolenic acid composition for CPO, RBDPO, RBDPOo and RBDPS did not (P > 0.05). The stability study indicated that the quality of the palm oil products was stable within the specified limits throughout the storage period at low temperature. The storage conditions preserved the quality of palm oil products throughout the storage period. These findings qualify the use of the palm oil products CPO, RBDPO, RBDPOo and RBDPS as control samples in the validation of test results. © 2017 Society of Chemical Industry.

TRIBOLOGICAL PROPERTIES OF POTENTIAL BIO-BASED LUBRICANTS FROM RBD PALM STEARIN AND PALM FATTY ACID DISTILLATE

Palm-based oil properties, which consist of long fatty acid chains, have the potential to replace current mineral oils. Recent studies have shown that palm-based oil has comparable lubricating properties to those of commercial engine oil. However, several palm oil products yet to be discover as lubricants such as RBD Palm Stearin (RBD PS) and Palm Fatty Acid Distillate (PFAD) due to its solid form properties. In this study, both RBD PS and PFAD has been tested for the suitability as lubricant in the tribological experiments consists of anti-wear test and extreme pressure test according to ASTM standards of D4172 B and 2783 respectively. In ASTM D4172 B, test has been conducted with 40kg load and 1200 rpm speed at 75°C in duration of 60 minutes while in ASTM 2783 the temperature and speed are remain constant at 45°C and 1760 rpm in duration of 10 minutes with increasing loads until failure detected. Mineral Oil (MO) has been used as a direct comparison between commercial engine oil and bio-based palm oil. Results shows PFAD has recorded lowest average coefficient of friction (COF), wear scar diameter (WSD) and surface roughness at 0.038, 433µm and 0.188µm in anti-wear test. In the extreme pressure test, RBD PS shows the earliest failure of 4mm wear scar diameter at 126kg followed by palm fatty acid distillate and mineral oil at 130kg and 146kg load.

EFFECTS OF PALM OIL PRODUCTS ON GROWTH PERFORMANCE, BODY COMPOSITION AND FATTY ACID PROFILE OF JUVENILE MALAYSIAN MAHSEER (Tor tambroides)

This study was performed to investigate the effects of different types of palm oil on the survival, growth performance, body indices, lean percentage, body composition and fatty acid profile of juvenile Malaysian mahseer, Tor tambroides. Four extruded diets containing 5% crude palm oil (CPO), refined, bleached, deodorised palm oil (RBDPO), RBD palm olein (RBDPOo) and RBD palm stearin (RBDPOs) were prepared. Triplicate groups of T. tambroides juveniles (1.65 ± 0.6 g) were stocked in 60 litres aquaria at 20 fish per aquarium and fed the diets for 12 weeks. Fish fed CPO and RBDPOs diet showed the best feed conversion ratio (FCR), while the lowest viscero-somatic index (VSI) was observed in juveniles fed RBDPOo and RBDPOs. A significantly higher (P<0.05) protein and gross energy retention were observed in juveniles fed RBDPOs compared to those fed RBDPO. The highest muscular retention of n-3 and n-6 long-chain polyunsaturated fatty acids (n-3 and n-6 LC-PUFA) was observed in juveniles fed CPO diet. In addition to giving a higher PUFA ratio in mahseer muscle than other palm oil products, CPO was the most cost effective palm oil type and was recommended as the lipid source in the diet of T. tambroides juvenile.

Evaluation of RBD palm stearin as alternative lubricant for cold forward extrusion process

A rapid growth in awareness level over environmental problems have brought researchers to find a substitute lubricant to reduce the use of mineral based lubricants. In this paper, the lubrication performance of RBD palm stearin was evaluated in order to be utilized as alternative lubricant for metal forming lubricant. Commercial paraffinic mineral oil VG460 and VG95 were used for comparison purposes. The experiment was conducted using cold work extrusion apparatus that consists of taper die (made of tool steel SKD11) and a pair of billet (made of pure aluminium A1100). The results obtained from these experiments showed that RBD palm stearin can reduce extrusion load, produce a lower surface roughness value and have smooth surface profile compared to commercial paraffinic mineral oils. It is demonstrated that RBD palm stearin have promising lubrication performance and can be considered as alternative lubricant in metal forming process.

Improvement of the Lubrication Performance of RBD Palm Stearin as an Alternative Lubricant under Different Sliding Speeds

Vegetable oils have gained global att–ention to be used as an alternative lubricant to reduce the dependency on natural resources of petroleumbased lubricants due to concern over environmental problems. In this study, a refined, bleached and deodorized (RBD) palm stearin was chosen as the base lubricant, and its lubrication performance was investigated using a pin-on-disk tribotester. A zinc dialkyl-dithiophosphate (ZDDP) additive in concentrations of 1 wt%, 3 wt% and 5 wt% was blended with RBD palm stearin to improve the lubrication performance of the base lubricant. Commercial semi-synthetic oil (SAE15W50) was used for comparison purposes. The experiments were conducted under various sliding speeds (1.5 ms-1, 2.5 ms-1 and 3.5 ms-1) under normal force of 9.81 N for an hour. The lubrication performance of the tested lubricants was presented by the coefficient of friction, wear scar diameter, wear rate, surface roughness and wear worn surface of the pin specimen. The results show that an increase in ZDDP concentrations has improved the lubrication performance of the RBD palm stearin. RBD palm stearin with 5 wt% ZDDP additive shows a smaller coefficient of friction than that of SAE15W50, but creates a slightly larger wear scar diameter and wear rate.

INVESTIGATION OF MICRO-PITS FORMATION ON BILLET SURFACES IN PLANE STRAIN EXTRUSION

Extrusion is a process of pushing a material through a die to yield a desired cross-section product. The application of surface texture has become well known for enhancing tribological performance. In this research, the effect of micro-pits embedded on a work piece lubricated with vegetable oil using plain strain extrusion were studied and compared with those seen with mineral-based oil lubricant. The experiments were conducted at room temperature (around 27℃). A taper die with a 60 die half-angle, with micro-pits array, was prepared. Test lubricants used were paraffinic mineral oil (PMO) VG460 and VG95 and refined, bleached and deodorized (RBD) palm stearin. The results were analysed to determine the extrusion load and the billet’s surface roughness and plastic deformation. RBD palm stearin was recorded as having the highest extrusion load (83.15 kN).

THE EFFECTS OF THE DIE HALF ANGLE OF TAPER DIE ON PLANE STRAIN EXTRUSION

In this research, a study of the effect of a die half angle on the extrusion process has been performed. The experiments were conducted at room temperature around 27 °C. Two types of taper die with different die half angles (45° and 60°) were prepared. The test lubricants used were paraffinic mineral oil VG460 and Refined, Bleached and Deodorized (RBD) Palm stearin. The material of the workpiece (billet) was annealed with A1100 aluminium. The experimental results were focused on the extrusion load, tool and workpiece surface roughness and plastic deformation of the workpiece. The resultant relative velocity was calculated using a visioplasticity method. The results shows that a taper angle of 60° recorded higher resultant relative velocity with a lower extrusion load and surface roughness compare to the taper angle of 45°. The comparison study between Paraffinic Mineral Oil and RBD Palm Stearin shows no significant effect in both taper angles tested.

FORMULATION OF REFINED, BLEACHED AND DEODORISED PALM STEARIN WITH ZINC DIALKYL-DITHIOPHOSPHATE ADDITIVE AND ITS TRIBOLOGICAL PERFORMANCE

Vegetable oils have recently received worldwide attention for their use as a lubricant base stock that has numerous advantages, including their environmental friendliness. In this study, a refined, bleached and deodorised palm stearin was selected as the base lubricant, and its friction and wear performance were investigated with a pin-on-disk tribotester. The effect of zinc dialkyl-dithiophosphate (ZDDP) additive in concentrations of 1wt%, 3wt% and 5wt% on friction and wear performance were evaluated. Commercial semi-synthetic oil SAE 15W50 was used for comparison purposes. The experiments were conducted at a sliding speed of 1.5 m/s under a normal force of 9.81 N for 60 min. Results show that an increase in ZDDP concentrations improved both friction reduction and wear performance of the lubricant. The coefficient of friction (COF) of RBD palm stearin was reduced approximately at 71% when 5wt% of ZDDP was added and it shows that the friction reduction performance of PS+5wt% (COF=0.039) was comparable to SAE 15W50 (COF=0.035). While, wear coefficient of RBD palm stearin was reduced significantly from 2.08 × 10−3 to 8.89 x 10−5 when 5wt% ZDDP additive was added and it shows that the wear performance of PS+5wt% was better than that of SAE 15W50, 1.94 x 10−4. Further analysis of the wear worn surface with a high-resolution optical microscope was also conducted with a surface profilometer to examine the metallurgy of the pin surface and the roughness of the pin.

MODIFICATION OF RBD PALM KERNEL AND RBD PALM STEARIN OIL WITH ZDDP ADDITIVE ADDITION

Vegetable oils have gained worldwide concern due to environmental issues since it is biodegradable, renewable and environmental-friendly. However, the limitations of vegetable oils such as having low oxidation stability and poor low temperature properties need to be solved. The purpose of this paper is to evaluate the tribological behavior of refined, bleached and deodorized (RBD) palm kernel and RBD palm stearin by using a modified pin-on-disc tester. The influence of an anti-wear/extreme pressure (AW/EP) additive on the anti-friction and anti-wear characteristics was also evaluated. The experiment was carried out by varying zinc-dialkyl-dithiophosphate (ZDDP) additive concentration of 1wt%, 3wt% and 5wt%; load of 1kg, sliding speed of 2.5 m/s, test duration of 60 minutes and at room temperature. The findings have revealed that without an additive, RBD palm kernel and RBD palm stearin have high friction coefficient and wear as compared with synthetic oils. The addition of additives helps in the improvement of tribological performance of tested vegetable oils. It can be concluded that vegetable oils have a great potential to be used as a petroleum-based substitute.

Lubricant Viscosity: Evaluation between Existing and Alternative Lubricant in Metal Forming Process

Lubrication in metal forming process is very important to control wear and friction at the interface between interacting surfaces. Non-renewable resources, such as mineral oil are widely used since a beginning due to its ability to act as a reservoir to the wearing contact which functions as a film material or sustains chemical transformation to become a film material. There is big concern that an alternative metal forming lubricant with similar viscosity able to replace existing metal forming lubricant without neglecting all main factors as demanded by industries. Two additives free paraffinic mineral oil with variable viscosity; VG95 and VG460 and daphnee were choose as existing lubricants, and is compared to an alternative lubricant with similar viscosity; RBD palm stearin and RBD palm kernel. The experiment used a cold work extrusion apparatus consisting of a pair of taper die and a symmetrical work piece (billet). The billet material was annealed pure aluminum A1100 with 45 of edge at the deformation area. It was found that lubricant with high viscosity performed slightly low extrusion load, but resulting higher surface roughness than low viscosity lubricants. However they show no severe wear on product surface.

The Effect of Temperature on the Tribological Behavior of RBD Palm Stearin

The wide use of petroleum-based oils raises concerns with regard to pollution, and the rising of awareness of greenhouse gases has created a demand for the use of environmentally friendly and biodegradable lubricants for industrial applications. Vegetable oils are one of the bio-oils that have been promoted as a replacement for petroleum products, in part due to their environmentally friendly characteristics; they are nontoxic, biodegradable, and easy to dispose of. Many researchers have performed studies on sunflower oil, corn oil, and soy oil, but few have studied palm oil as a lubricant. Palm oil produced in a high-throughput manner could fulfill the demand for bio-based lubricants. In this study, the influence of temperature on friction and wear performance for refined, bleached, and deodorized (RBD) palm stearin and additive-free paraffinic mineral oil is presented. The experiments were conducted using a four-ball tribotester. Test temperatures of 55, 65, 75, and 85°C were used. The sliding speeds were set to 1,200 rpm. Experiments were run for 1 h under a 392.4 N load. The results of RBD palm stearin were compared with those of paraffinic mineral oil. The experimental results showed that the RBD palm stearin had better performance compared to paraffinic mineral oil in terms of reducing frictional constraints.

Experimental Evaluation of Refined, Bleached, and Deodorized Palm Olein and Palm Stearin in Cold Extrusion of Aluminum A1050

The performance of palm oil as a lubricant in a cold metal forming process was tested and evaluated by carrying out plane strain extrusion experiments and experimental analyses using a visioplasticity method. In the present research, two types of refined palm oil, refined, bleached, and deodorized (RBD) palm olein and RBD palm stearin, were tested as lubricants. The workpiece material was aluminum JIS-A1050. The experiments were carried out at room temperature (22°C). Paraffinic mineral oils with varying degrees of viscosity were tested for comparison. The experiment used an extrusion apparatus in which the taper dies were facing together, with zero frictional constraint at the contact plane (corresponding to the plane plate tool) conducted, and results were compared with those extruded with lubricants. Extrusion load and surface roughness of the billets were measured and compared. The distribution of the material flow velocity and effective strain in the exit zone of the billets were calculated using the visioplasticity method, and these data were also compared. The results confirmed that RBD palm olein and palm stearin provide sufficient lubrication performance in the cold work metal forming process.

Enzymatic Synthesis of Fatty Hydrazides from Palm Oils

Fatty hydrazides (FH) have been successfully synthesized from palm oils by a one-step lipase catalyzed reaction. The synthesis was carried out by treating the oils with hydrazine hydrate at neutral pH using an immobilized lipase, Lipozyme as the catalyst. The percentages of conversion of RBD (refined, bleached and deodorized) palm oil (PO), RBD palm olein (POn), RBD palm stearin (PS) and RBD palm kernel olein (PKOn) into their fatty hydrazides are 95, 97, 97 and 99, respectively.

Rapid synthesis of palm‐based monoacylglycerols

AbstractRapid synthesis of high‐purity MAG from refined, bleached, and deodorized palm stearin (RBDPS) via chemical glycerolysis in the presence of pyridine was developed to obviate the conventional molecular distillation in the production of pure MAG. The optimal reaction for the sodium methoxide‐catalyzed glycerolyis of RBDPS was recorded at 110°C using a 3 wt% catalyst concentration based on the weight of RBDPS, with an RBDPS/glycerol ratio of 1∶2 and an RBDPS/pyridine ratio of 1∶4. High yields of over 99% were achieved rapidly in 15 min, and increases in DAG and FFA were observed after a prolonged reaction time.

Enzymatic Synthesis of Fatty Hydroxamic Acids from Palm Oil

Fatty hydroxamic acids (FHA) have been successfully synthesized from palm oils by a one-step lipase catalyzed reaction. The use of immobilized lipase as the catalyst for the preparation reaction provides an easy isolation of the enzyme from the products and other components in the reaction mixture. In addition, it also allows the reaction to be carried out under mild conditions, which reduces the reaction’s side products. The percentages of conversion of commercial palm olein (CPOn), RBD (refined, bleached and deodorized) palm olein (POn), RBD palm oil (PO), RBD palm stearin (PS) and RBD palm kernel olein (PKOn) into their fatty hydroxamic acids are 89, 79, 77, 90 and 98, respectively.

Composition and thermal profile of crude palm oil and its products

AbstractGas‐liquid chromatography and high‐performance liquid chromatography (HPLC) were used to determine fatty acids and triglyceride (TG) compositions of crude palm oil (CPO), refined, bleached, and deodorized (RBD) palm oil, RBD palm olein, and RBD palm stearin, while their thermal profiles were analyzed by differential scanning calorimeter (DSC). The HPLC chromatograms showed that the TG composition of CPO and RBD palm oil were quite similar. The results showed that CPO, RBD palm oil, RBD olein, and superolein consist mainly of monosaturated and disaturated TG while RBD palm stearin consists mainly of disaturated and trisaturated TG. In DSC cooling thermograms the peaks of triunsaturated, monosaturated and disaturated TG were found at the range of −48.62 to −60.36, −25.89 to −29.19, and −11.22 to −1.69°C, respectively, while trisaturated TG were found between 13.72 and 27.64°C. The heating thermograms of CPO indicated the presence of polymorphs β2′, α, β2′, and β1. The peak of CPO was found at 4.78°C. However, after refining, the peak shifted to 6.25°C and became smaller but more apparent as indicated by RBD palm oil thermograms. The heating and cooling thermograms of the RBD palm stearin were characterized by a sharp, high‐melting point (high‐T) peak temperature and a short and wide low‐melting point (low‐T) peak temperature, indicating the presence of occluded olein. However, for RBD palm olein, there was only an exothermic low‐T peak temperature. The DSC thermograms expressed the thermal behavior of various palm oil and its products quite well, and the profiles can be used as guidelines for fractionation of CPO or RBD palm oil.

Replacement of animal fat with fractionated and partially hydrogenated palm oil in beef burgers

Four formulations of burgers, prepared with 65% lean meat and 15% fat consisting of RBD palm stearin (PS), Socfat 4000P and Socfat 4100P and beef fat (BF) as control were evaluated for solid fat content (SFC), slip melting point (SMP), cooking loss, proximate analysis (moisture, fat and protein), colour, i.e. lightness (‘L’), redness (‘a’) and yellowness (‘b’), free fatty acid (FFA), iodine value (IV), thiobarbituric acid (TBA) and texture profile analysis (TPA). Sensory evaluation was carried out for texture, juiciness, aroma, oiliness and overall acceptance. SFC and SMP for raw and cooked SF4000P beef burgers were closest to BF control burgers, falling into the range of 35–40°C. Cooking loss was highest for PS burgers, there were no significant differences (P > 0.05) amongst BF, SF4000P and SF4100P burgers. Proximate analysis on raw burgers showed SF4000P to contain high fat and lowest moisture contents. Objective textural measurements using texture profile analysis (TPA) for all cooked burgers showed no significant differences (P > 0.05) for springiness and cohesiveness. Variation of values among the formulations for hardness, gumminess and chewiness are explained by the differences of SFC for beef burgers with various types of fats. Raw and cooked PS burgers have the lightest ‘L’ values compared with other fat-substituted burgers while BF, SF4000P and SF4100P indicated no significant differences (P > 0.05) for ‘L’, ‘a’ and ‘b’ values. Beef fat showed the highest amount of free fatty acids (FFA) compared to palm oil samples. For the iodine value (IV), SF4000P showed the highest value which means that it contained the highest level of unsaturated fatty acids followed by PS, BF and SF4100P successively. SF4000P had the highest TBA values followed successively by BF, PS and SF4100P. For sensory evaluation, PS burgers had the least oily taste. This may be due to its high cooking loss. Taste panelists could not differentiate burgers with substituted vegetable fats against the control burgers.

Colorimetric determination of total tocopherols in palm oil, olein and stearin

AbstractBy using a preliminary heat‐bleach at 250 C the Emmerie‐Engel method has been adapted for the determination of total tocopherols (including tocotrienols) in crude as well as refined palm oil, olein and stearin. Total tocopherol contents found were: Crude palm oil, 794 ppm (n=10); RBD palm oil, 563 ppm (n=13); RBD palm olein, 643 ppm (n=40); RBD palm stearin, 261 ppm (n=19), where n is the number of samples analyzed. During the detergent fractionation no tocopherols were lost, but the tocopherols were concentrated in the olein fraction.The fate of the tocopherols during degumming, bleaching and steam refining/deodorizing of Crude palm olein containing 978 ppm total tocopherol was studied. Over the whole refining process only 8% of the tocopherols were lost, 62% of the original tocopherols were retained in the RBD palm olein, while the remaining 30% were concentrated in the fatty acid distillate which contained 7,040 ppm tocopherol.