Refined Bleached Deodorized Research Articles

Antioxidant potential of corncob extracts for stabilization of corn oil subjected to microwave heating

Antioxidant effectiveness of corncob extract with different polarity solvents ( n-hexane, ethyl acetate, acetone, ethanol, and methanol) was assessed for total phenolics content (TPC), DPPH radical scavenging activity and % inhibition of peroxidation in linoleic acid system. The yield of the extracts from corncob with different solvents ranged from 1.1 to 19.5 g/100 g of dry matter. TPC, DPPH radical scavenging and inhibition of linoleic acid oxidation for corncob extracts varied significantly ( P < 0.05) from 1.2 to 4.2, 16.0 to 42.1, and 37.3 to 89.9 g/100 g per dry matter, respectively. Methanolic extract offered the highest yield (19.5%), and also exhibited superior antioxidant activity. Corncob methanolic extract was added at concentrations of 500 and 1000 ppm to RBD (refined, bleached, deodorized) corn oil. BHT at 200 ppm served as standard beside the control. The stabilized corn oil samples subjected to microwave heating (0–21 min) were analyzed periodically. The magnitude of oxidative alterations was followed by the measurement of conjugated dienes (CD), conjugated trienes (CT), p-ansidine, and peroxide values. Results of different oxidation parameters revealed that methanolic extract at concentration of 1000 ppm was more effective than BHT and inhibited the rise in p-ansidine-, conjugated diene-, conjugated triene-, and peroxide-values up to 41.8%, 45.0%, 39.7%, and 65.0%, respectively, with respect to the control.However, at concentration of 500 ppm offered less efficient protection. The results of different antioxidant parameters investigated in the present study demonstrated that corncob is a potent source of natural antioxidants that might be explored to prevent oxidation of vegetable oils.

Immobilization and biocatalysis of chlorophyllase in selected organic solvent systems

Chlorophyllase extract from Phaeodactylum tricornutum was immobilized by physical adsorption on DEAE-cellulose and silica gel as well as by covalent binding on Eupergit C, Eupergit C250L, Eupergit C/ethylenediamine (EDA) and Eupergit C250L/EDA. Although the highest immobilization yield (83–93%) and efficiency (51–53%) were obtained when chlorophyllase extract was immobilized on DEAE-cellulose and silica gel, there was no improvement in the thermal stability of chlorophyllase as compared to that of the free one. The immobilization of chlorophyllase extract on Eupergit C250L/EDA resulted by a high recovery of enzymatic activity, with an immobilization efficiency of 44%, and promoted a higher stabilization of chlorophyllase (four times) in the aqueous/miscible organic solvent medium. On the other hand, the inhibitory effect of refined bleached deodorized (RBD) canola oil was reduced by immobilization of chlorophyllase extract onto silica gel as compared to those obtained with other enzyme preparations. However, the re-cycled chlorophyllase extract immobilized on Eupergit C250L/EDA retained more than 75% of its initial enzyme activity after 6 cycles, whereas that immobilized on silica gel was completely inactivated. The highest catalytic efficiency, for both free and immobilized chlorophyllase on Eupergit C250L/EDA, was obtained in the ternary micellar system as compared to the aqueous/miscible organic solvent and biphasic media.

Chlorophyllase biocatalysis in an aqueous/miscible organic solvent medium containing canola oil

AbstractChlorophyllase catalyzes the bioconversion of chlorophyll into chlorophyllide by replacing the phytol group with a hydrogen atom. There is an increased interest in the biotechnological application of chlorophyllase for the removal of green pigments from edible oil and its potential as an alternative to the use of the conventional bleaching technique. Partially purified chlorophyllase, obtained from the alga Phaeodactylum tricornutum, was assayed for its hydrolytic activity in an aqueous/miscible organic solvent system containing refined‐bleached‐deodorized (RBD) canola oil, using chlorophyll and pheophytin as substrate models. The results indicated that chlorophyllase biocatalysis could be successfully carried out in an aqueous/miscible organic system containing RBD canola oil. The presence of 20% RBD canola oil decreased the hydrolytic activity of chlorophyllase by 2.2 and 6.7 times, using chlorophyll and pheophytin as substrates, respectively. In addition, acetone acted as an activator of chlorophyllase activity at low concentrations and an inhibitor at higher ones. The optimal reaction conditions for chlorophyllase biocatalysis in the aqueous/miscible organic system were determined to consist of 20% RBD oil and 10% acetone at a 200 rpm agitation speed and at a temperature and substrate concentration of 35°C and 12.6 μM for chlorophyll, and 30°C and 9.3 μM for pheophytin.

Detection of lard adulteration in RBD palm olein using an electronic nose

The use of surface acoustic wave (SAW) sensing electronic nose (zNose™) for detection of lard as an adulterant in refined, bleached, deodorized (RBD) palm olein was investigated. Mixing of animal fats, especially lard in any form in food products, is a cause of concern for certain religions. RBD palm olein spiked with lard at levels ranging from 1% to 20% (w/w) was analyzed. The zNose™ produced a two-dimensional olfactory image called VaporPrint™, which could be used for immediate detection (qualitatively) of lard substances in sample admixtures. Lard adulteration could be determined by a few distinct peaks in the zNose™ chromatogram. The best relationship between percentage of lard in adulterated RBD palm olein and SAW detector response was observed in adulterant peak E ( R 2 = 0.906). Pearson’s correlation coefficient ( r) was calculated using this parameter. An ideal correlation was observed between the zNose™ data and other chemical tests ( r > 0.90).

Chemical composition and physicochemical and hydrogenation characteristics of high‐palmitic acid solin (low‐linolenic acid flaxseed) oil

AbstractThe physicochemical characteristics and FA compositions were determined for refined‐bleached‐deodorized (RBD) high‐palmitic acid solin (HPS) oil, RBD solin oil, and degummed linseed oil. The predominant FA in HPS oil were palmitic (16.6%), palmitoleic (1.4%), stearic (2.5%), oleic (11.3%), linoleic (63.7%), and linolenic (3.4%). HPS oil was substantially higher in palmitic acid than either solin oil or linseed oil, and similar to solin oil in linolenic acid content. HPS, solin, and linseed oils exhibited similar sterol and tocopherol profiles. The physicochemical characteristics of the three oils (iodine value, saponification value, m.p., density, specific gravity, viscosity, PV, FFA content, color) reflected their FA profiles and degree of refinement. During hydrogenation of HPS oil, the proportion of saturated FA (palmitic and stearic) increased, and that of unsaturated FA (oleic, linoleic, and linolenic) decreased as the iodine value declined. This resulted in an inverse linear relationship between m.p. and iodine value. Hydrogenation also generated trans FA. The proportion of trans FA was inversely related to iodine value in partially hydrogenated samples. Fully hydrogenated HPS oil (i.e., HPS stearine, iodine value &lt;5) was devoid of trans FA.

Detection of lard and randomized lard as adulterants in refined‐bleached‐deodorized palm oil by differential scanning calorimetry

AbstractA study was conducted to assess the use of differential scanning calorimetry (DSC) for detecting the presence of lard/randomized lard as adulterants in refined‐bleached‐deodorized (RBD) palm oil. Lard extracted from the adipose tissues of pig was chemically interesterified using sodium methoxide as catalyst. DSC thermal profiles of both genuine lard and randomized lard were compared with those of other common animal fats such as beef tallow, mutton tallow, and chicken fat. Lard and randomized lard were then blended with RBD palm oil in two series, in proportions ranging from 0.2 to 20%, and DSC analyses were obtained. The DSC cooling profiles of adulterated RBD palm oil samples showed an adulteration peak corresponding to lard/randomized lard in the low‐temperature region. This peak was confirmed as an indicator of the presence of lard in RBD palm oil since similar experiments carried out using other common animal fats such as mutton tallow, beef tallow, and chicken fat showed that the lard adulteration peak could be distinctly identified. Using this method, a detection limit of 1% lard/randomized lard was reached (P&lt;0.0001).

Cholesterol vehicle in experimental atherosclerosis. 22. Refined, bleached, deodorized (RBD) palm oil, randomized palm oil and red palm oil

The atherogenic effects of refined, bleached and deodorized (RBD) palm oil were compared with those of randomized RBD palm oil and red palm oil. RBD palm oil contains 41.2% palmitic acid, 2.6% at the SN2 position. In randomized palm oil, 13.6% of the palmitic acid is in the SN2 position. Randomized palm oil is significantly more atherogenic for rabbits than is RBD palm oil, supporting our earlier findings that the increasing amounts of palmitic acid in the SN2 position of a fat lead to an increased atherogenic effect. Red palm oil is the oil initially obtained from the palm fruit which contains carotenes and Vitamin E that are removed during refining. Red palm oil was significantly less atherogenic than RBD palm oil supporting the hypothesis that carotenoids and Vitamin E may protect against atherosclerosis. The oils tested had similar effects on serum and liver lipids.

Development of zero ODP rigid polyurethane foam from RBD palm kernel oil

In recent years, the use of renewable resources has attracted the attention of many technologists as potential substitutes for petrochemicals, mainly from forest products. Palmeri oil, vernonia oil, castor oil and recently the cardanol oil are naturally synthesized with multiple functionality and are a new source of renewable resources which have a very bright future as an alternative to petroleum feedstock [1–3]. Since the invention of polyurethane by Bayer in 1937, the utilization of polyurethane is ubiquitous. Polyurethanes are block copolymers containing blocks of low molecular weight polyesters or polyethers covalently bonded by a urethane group (-NHCO=O). These polymers are synthesized by reacting three basic components consisting of polyisocyanate, polyhydroxyl-containing polymer (i.e. polyester or polyether polyols) and a chain extender, which is usually low molecular weight diols or diamines (i.e. 1,4-butanediol or 1,4-dibutylamine) [4]. Currently, there is a wide range of polyisocyanates, polyols and chain extenders commercially available and this has led to almost unlimited possibilities for polyurethane materials. Because of the inherent versatility on polyurethane syntheses, the properties of this class of polymers can be easily engineered to suit the applications required. Palm kernel oil is the focus of this study because it is available in abundance in Asia, especially Malaysia. In addition, it is produced from the production of palm fruit as much as 3.8 tons per hectare per annum [5], as well as offering very low market price. In this study, the RBD (refined-bleached-deodorized) palm kernel oil was derivatized using a new development in polyurethane technology by combination with polyethylene glycol under basic condition. Methods used in the process involved polycondensation and transesterification [6] where low reaction temperature and short reaction time as well as high percentage of yield are offered. The RBD palm kernel oil (Lee Oilmill, Klang) together with a reagent, which was a mixture of proprietary polyhydroxyl compound and basic catalyst were reacted at ratio of 80 : 20 to get the highest functionality value possible. The reaction was carried out in laboratory scale. The mixture was continuously stirred in a 2L-glass reactor and was maintained at 183± 2 ◦C for 20–30 min, with nitrogen blanket throughout the process. The reflux flask was connected to a condenser and the vacuum pump to withdraw the water from the system. The progress of the reaction was monitored by sampling at intervals. The samples were then analyzed. At the end of the reaction, the polyol produced was kept in a sealed cap glass container for analysis. 120 g of crude MDI (Cosmonate M-200, Cosmopolyurethane, Port Klang) was poured into 100 g of the mixture of the RBD palm kernel oil polyol with additives (surfactant, catalyst and water) and was mixed thoroughly using a standard propeller with speed of 3500 rpm for 10 s. The mixture was then poured into a waxed mold, covered and screwed tight. The foam was demolded after 10 min. It was then conditioned for 16 h at 23± 2 ◦C before characterization. Foams were characterized for their apparent densities, compression strength, dimensional stability and water absorption following the standard method BS 4370: Part 1: 1988 (Rigid polyurethane foam produced by the press injection method). The RBD palm kernel oil changed from a cloudy pale yellow solid (at 24–25 ◦C) before derivatization to a clear golden yellow liquid after reaction. It has a viscosity of 262.5 mpa s and density 948.2 kg/m3 at 25 ◦C. The moisture content was 0.12% and it had a pH value of about 9–10. The cloud point was observed at 13 ◦C. The hydroxyl number calculated was approximately in the range of 350–370 mg KOH/g sample. Through gel permeation chromatography (GPC), the molecular weight was calculated at the range of 430– 450, leading to functionality value of 2.8–3.0. The purity of the synthesized polyol was checked by thin layer chromatography and was confirmed to be reproducible. Fig. 1 show the two peaks used for monitoring the derivatization process. Peak B does not appear in the FTIR spectrum of underivatized RBD palm kernel oil. The ratios of the percentage transmittance of these two peaks are calculated and plotted against the reaction temperatures.

MONITORING OF TRANSESTERIFICATION OF PALM OIL BY DIFFERENTIAL SCANNING CALORIMETRY

ABSTRACT Chemical transesterification was conducted to obtain triacylglycerol (TG) containing maximum concentrations of trisaturated and triunsaturated TG in palm oil. Catalyst (sodium methoxide) concentration of 0.1–0.5%, reaction temperature of 50–92C and reaction time of 30–480 min were applied in 20 treatments. Concentrations of trisaturated and triunsaturated TG, as well as melting points and iodine values were monitored by differential scanning calorimetric (DSC) techniques. The results showed that maximum trisaturated and triunsaturated TG achieved for refined‐bleached‐deodorized (RBD) palm oil were 17.10 and 7.50%, respectively, using 0.42% catalyst, at 58C in 389 min. These amounts were higher compared to control (untransesterified) RBD palm oil i.e 7.45 and 4.92%, respectively. The melting points of the products were higher compared to the control, while the iodine values were not significantly changed in all of the treatments.

Determination of free fatty acids in crude palm oil and refined‐bleached‐deodorized palm olein using fourier transform infrared spectroscopy

AbstractA rapid direct Fourier transform infrared (FTIR) spectroscopic method using a 100 µ BaF2 transmission cell was developed for the determination of free fatty acid (FFA) in crude palm oil (CPO) and refined‐bleached‐deodorized (RBD) palm olein, covering an analytical range of 3.0–6.5% and 0.07–0.6% FFA, respectively. The samples were prepared by hydrolyzing oil with enzyme in an incubator. The optimal calibration models were constructed based on partial least squares (PLS) analysis using the FTIR carboxyl region (C=O) from 1722 to 1690 cm−1. The resulting PLS calibrations were linear over the range tested. The standard errors of calibration (SEC) obtained were 0.08% FFA for CPO with correlation coefficient (R2) of 0.992 and 0.01% FFA for RBD palm olein with R2 of 0.994. The standard errors of performance (SEP) were 0.04% FFA for CPO with R2 of 0.998 and 0.006% FFA for RBD palm olein with R2 of 0.998, respectively. In terms of reproducibility (r) and accuracy (a), both FTIR and chemical methods showed comparable results. Because of its simpler and more rapid analysis, which is less than 2 min per sample, as well as the minimum use of solvents and labor, FTIR has an advantage over the wet chemical method.

Determination of free fatty acids in palm oil by near‐infrared reflectance spectroscopy

AbstractA near‐infrared (NIR) spectroscopy calibration was developed for the determination of free fatty acids (FFA) in crude palm oil and its fractions based on the NIR reflectance approach. A range of FFA concentrations was prepared by hydrolyzing oil with 0.15% (w/w) lipase in an incubator at 60°C (200 rpm). Sample preparation was performed in Dutch cup, and the spectra were measured in duplicate for each sample. The optimized calibration models were constructed with multiple linear regression analysis based on C=O overtone regions from 1850–2050 nm. The best wavelength combinations were 1882, 2010, and 2040 nm. Multiple correlation coefficients squared (R2) were: 0.994 for crude palm oil, 0.961 for refined‐bleached‐deodorized (RBD) palm olein, and 0.971 for RBD palm oil. Calibrations were validated with an independent set of 8–10 samples. R2 of validation were 0.997, 0.943, and 0.945, respectively. The developed method was rapid, with a total analysis time of 5 min, and environmentally friendly, and its accuracy was generally good for raw‐material quality control.

Development of a rigid polyurethane foam from palm oil

The reactions between polymeric diphenyl methane diisocyanate (polymeric MDI) and conventional polyols to produce foamed polyurethane products are well documented and published. Current polyurethane foams are predominantly produced from these reactions whereby the polyol components are usually obtained from petrochemical processes. This article describes a new development in polyurethane foam technology whereby a renewable source of polyol derived from refined–bleached–deodorized (RBD) palm oil is used to produce polyurethane foams. Using very basic foam formulation, rigid polyurethane foams were produced with carbon dioxide as the blowing agent generated from the reaction between excess polymeric MDI with water. The foams produced from this derivatized RBD palm oil have densities in excess of 200 kg/m3 and with compression strengths greater than 1 MPa. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 509–515, 1998

Triacylglycerols responsible for the onset of nucleation during clouding of palm olein

AbstractThis paper discusses the results of an investigation to identify triacylglycerols that induce clouding of refined bleached deodorized (RBD) palm olein, which occurred within 24 h after fractionation. The experiments were conducted in a jacketed glass vessel in which the liquid sample was cooled from 70 to 23°C at a predetermined rate. Clouding began at around 28.5°C. The presence of three different types of saturated triglycerides, namely tripalmitin, dipalmitoyl‐myristoylglycerol and dipalmitoyl‐stearoyl‐rac‐glycerol, is critical in the formation of nuclei and thus clouding of the RBD palm olein. This conclusion is based on the significant increase in the relative concentration of these components in the nuclei as compared to the mother oil.

Comparison of visual and automated colorimeters—An international collaborative study

AbstractColor as a fundamental quality of edible oils has been determined primarily by visual comparison methods for many decades. The automatic colorimeters introduced recently made it possible to replace the manually operated visual color instrument, which requires experience to master and is often subject to operator variabilities. A previous study with an automatic colorimeter, Colourscan, to measure the colors of refined and refined bleached cottonseed oils showed good agreement (r2=0.99) with visual color measurements by means of the Lovibond‐AOCS Color Scale. The current work is to establish a broad‐scale correlation between the automated colorimeter and visual color measurements. In this international effort, factory‐processed refined and refined, bleached, deodorized (RBD) canola, corn, cottonseed, peanut, sunflower and soybean oils, as well as refined palm olein, RBD palm oil, and washed, dried, filtered and deodorized tallow were used. A total of 14 laboratories from the United States and Canada, and 16 laboratories from 12 countries outside of North America, participated in this collaborative study. The results of this study, with statistical analyses, are reported.

BIOCATALYSIS OF CHLOROPHYLLASE IN CANOLA OIL USING ORGANIC SOLVENT SYSTEMS

The hydrolytic activity of a partially purified chlorophyllase, obtained from an algal source, was investigated in a refined-bleached-deodorized (RBD) canola oil model system using various organic solvent media, including water/miscible-organic, biphasic organic, and micellar ternary systems. Although the use of a a ternary micellar system containing Span 85 was found to be the most appropriate medium for the hydrolysis of chlorophyll, the hydrolytic activity of chlorophyllase declined as oil content increased. The effects of various parameters, including surfactant concentration, hexane/buffer proportion, enzyme content, reaction time, incubation temperature, shaker speed, and activator concentration, on chlorophyllase activity in the micellar ternary systems containing 20% RBD oil were also investigated. In addition, phytol displayed a noncompetitive inhibition in reaction media containing polysorbate 80 and Span 85. The plot of 1/v versus oil concentrations revealed that the oil had K i values of3. 73 and 4.56% in the micellar systems containing polysorbate 80 and Span 85, respectively. Moreover, the presence of 10% oil in the micellar system containing span 85 and polysorbate 80 decreased V max values of chlorophyllase activity by 6.2 and 9.6-fold, respectively.

Modelling the temperature dependence of kinematic viscosity for refined canola oil

Viscosities of refined, bleached, deodorized (RBD) and refined, bleached, winterized (RBW) canola oils were measured at temperatures from 4 to 100°C. The viscosities of these refined canola oils were exponentially related to the oil temperature. Viscosity of the RBW oil was slightly greater than that of the RBD oil when the temperature was below 15°C. Compared to refined soybean oil, the canola oils were substantially more viscous. The viscosity of canola oil was modelled asv = exp(C0 + C1T + C2T2). The maximum predicted error was less than 1.6% over the tested temperature range.