PROCESS INTENSIFICATION OF MEMBRANE SYSTEM FOR CRUDE PALM OIL PRETREATMENT

In the study conventional refining, microfiltration and ultrafiltration processes have been used experimentally to pretreat crude palm oil (CPO) samples with the aim of moving from the usual huge refinery plant to a more process integrated membrane module at ultrascale size that will even perform better than the former. Reduction of phosphorus for the membrane‐permeate of 43.4% was higher than that of bleached oil of 34.4%. When ceramic membranes with pore diameters of 0.45 µm and 0.2 µm were used in microfiltration, it was found that membrane with pore size of 0.45 µm was able to reject 14% of phosphorus, while ceramic membrane with pore size of 0.2 µm showed better phosphorus rejection of 56.8%. Upon applying ceramic membrane with pore sizes of 20 nm and 50 nm, 78.1% and 60% of phosphorus were rejected, respectively. Attributed to the superior performance of the membrane with 20 nm pore size over other membranes and conventional refining method on phosphorus content, a simulation study thus made, showed that the average slurry volume after about 22‐min runs for membrane with pore sizes of 0.45 µm, 0.2 µm, 50 nm and 20 nm, and the average slurry volumes are 0.05, 0.09, 0.13 and 0.18 m ³ , respectively. The percentage decrease between membrane pore size of 0.45 µm and 0.2 µm; 0.45 µm and 50 nm; and 0.45 µm and 20 nm are 73, 49 and 24%, respectively. The ultrafiltration achieved order of process miniaturization of about 10 ² ?10 ³ , which is in accordance with literature. This is a considerable size reduction in the process size, which reflects the magnitude of slurry volume that can be produced within a given time and meets every standard for process intensification through simulated process miniaturization.     

QUALITY INSPECTION OF BAKERY PRODUCTS USING A COLOR-BASED MACHINE VISION SYSTEM

Muffins were evaluated for color by visual examination and by development of a machine‐reading system coupled with discriminant analysis of the data acquired. A classification algorithm separated light from dark‐colored muffins. The system's precision was assessed by evaluating the color of 4 cm diameter muffins pregraded prior to the evaluation of color and without pregrading. Applied to 200 samples, the automated system was able to correctly classify 96% of the pregraded and 79% of the ungraded muffins. The algorithm procedure was able to classify muffins at an accuracy level better than 88% in most cases whereas quality decisions among inspectors varied by 20 to 30%. Critical to precision by the machine‐read procedure was control of the illumination.     

RECOVERY OF PALM CAROTENE FROM PALM OIL AND HYDROLYZED PALM OIL BY ADSORPTION COLUMN CHROMATOGRAPHY

Crude palm oil and crude palm olein were hydrolyzed with lipase from Candida rugosa to produce a free fatty acid (FFA) rich oil. The percentages of FFA produced and carotene degradation after the hydrolysis process were determined. The palm oil and hydrolyzed palm oil were subsequently subjected to column chromatography. Diaion HP-20 adsorbent was used for reverse phase column chromatography at 50C. Isopropanol or ethanol, and n-hexane were used as the first and second eluting solvents, respectively. The objective of hydrolyzing the palm oil was to produce more polar FFA-rich oil in order to enhance the nonpolar carotene bind to the nonpolar HP-20 adsorbent in the column chromatography process. Hydrolyzing palm oil with lipase from Candida rugosa gave 30- and 60-fold, respectively, of FFA in the crude palm oil and crude palm olein in 24 h at 50C. Approximately, 15.56 and 17.48% of carotene degraded in crude palm oil and crude palm olein, respectively. For column chromatography, using isopropanol or ethanol as the first eluting solvent, unhydrolyzed oil and hydrolyzed oil showed the carotene recovery infraction two (carotene-rich fraction) of about 36–37 and 90–96%, respectively. Over 90% of carotene recovery was obtained from     

FUNCTIONALITY OF PALM OIL IN FOODS

The functional properties of commercial solid fats such as shortening and margarine are closely related to their fatty acid and triacylglycerol compositions. Plastic fats produced from hydrogenated seed oils may suffer from undesirable crystal structure changes during handling and storage. It has been demonstrated that this problem increases with increasing chain length uniformity of the component fatty acids. This is also evidenced by the carbon number composition of the high melting triacylglycerols of the plastic fats. Triacylglycerols with carbon numbers 48 and 54 promote β crystallization, those with carbon numbers 50 and 52 promote β' crystallization. Since palm oil and its products contain high levels of C50 and C52 triacylglycerols they are useful for improving the functional properties of plastic fats.     

PRODUCTION OF PALM OIL REFERENCE MATERIALS FOR THE DETERMINATION OF SOLID FAT CONTENT

ABSTRACT

Three palm oil reference materials were produced for solid fat content analysis employing the Malaysian Palm Oil Board (MPOB) Test Methods. Thirteen laboratories participated in the characterization study, where the solid fat content in palm oil, palm olein and palm stearin were identified at temperature range from 0 to 45C. The consensus values were calculated based on the acceptability of statistical results from collaborating laboratories. Both of the consensus values and their uncertainties (%) for each reference material are as follows: 71.12 ± 1.82% (0C), 54.07 ± 1.05% (10C), 37.44 ± 0.88% (15C), 24.18 ± 1.09% (20C), 13.32 ± 0.86% (25C), 7.64 ± 0.28% (30C), 4.05 ± 0.14% (35C) and 1.25 ± 0.49% (40C) for SFC of palm oil, 66.32 ± 1.93% (0C), 43.53 ± 1.32% (10C), 22.50 ± 0.78% (15C), 6.68 ± 1.14% (20C) and 1.40 ± 0.35% (25C) for SFC of palm olein, and 78.09 ± 1.23% (0C), 67.66 ± 0.71% (10C), 56.29 ± 1.18% (15C), 44.37 ± 1.13% (20C), 30.22 ± 1.25% (25C), 20.08 ± 0.58% (30C), 13.72 ± 0.32% (35C), 8.97 ± 0.72% (40C) and 5.06 ± 0.41% (45C) for solid fat content of palm stearin.

PRACTICAL APPLICATIONS

The implementation of the ISO 17025 accreditation should be encouraged for testing laboratories to assure the traceability of analysis performed. This accreditation requires the use of certified reference materials to ensure that the analysis performed is parallel to the ISO 17025 standards. However, the unavailability of palm oil reference materials will affect the implementation of such standards for laboratories that are performing palm oil analyses. Hence, this study is aimed to characterize and certify the palm oil reference materials for determination of solid fat content. The establishment of this study is hoped to increase the credibility of laboratories, which are involved in the palm oil analysis. This will also promote the Malaysia Palm Oil Board as a center for the certification of palm oil reference materials.     

THE DEVELOPMENT OF A MACHINE VISION SYSTEM FOR SHIITAKE GRADING

A grading system was developed to classify shiitake automatically into various grades of quality in terms of size, shape and color. A shiitake is scanned with a color charge‐coupled‐device camera and then various geometrical and color characteristics are determined by image processing. The online grading procedure includes the following sequences in processing dried shiitake: (a) color abnormality is eliminated by image analysis; (b) broken caps are detected by calculation of the area‐to‐perimeter ratio; and (c) size is determined by pixel counting from the bottom view. Image processing and algorithmic manipulations are done on a personal computer (PC) while grading is carried out by a programmable logic controller (PLC). The PLC accepts grading instructions from the PC, hence controls the grading mechanisms. Pilot system validation was done on 250 dried shiitake samples and resulted in a 97.6% accuracy rate. This result is better than that by visual inspection. A complete grading cycle takes 4.8 s, of which the PC unit participates 0.3–0.7 s depending on the physical complexity of the shiitake being processed.     

SIMULATION OF THIN-FILM DEODORIZERS IN PALM OIL REFINING

As the need for healthier fats and oils (natural vitamin and trans fat contents) and interest in biofuels are growing, many changes in the world's vegetable oil market are driving the oil industry to developing new technologies and recycling traditional ones. Computational simulation is widely used in the chemical and petrochemical industries as a tool for optimization and design of (new) processes, but that is not the case for the edible oil industry. Thin-film deodorizers are novel equipment developed for steam deacidification of vegetable oils, and no work on the simulation of this type of equipment could be found in the open literature. This paper tries to fill this gap by presenting results from the study of the effect of processing variables, such as temperature, pressure and percentage of stripping steam, in the final quality of product (deacidified palm oil) in terms of final oil acidity, the tocopherol content and neutral oil loss. The simulation results have been evaluated by using the response surface methodology. The model generated by the statistical analysis for tocopherol retention has been validated by matching its results with industrial data published in the open literature.

PRACTICAL APPLICATIONS

This work is a continuation of our previous works ( Ceriani and Meirelles 2004a, 2006 ; Ceriani et al. 2008 ), dealing with the simulation of continuous deodorization and/or steam deacidification for a variety of vegetable oils using stage-wised columns, and analyzing both the countercurrent and the cross-flow patterns. In this work, we have studied thin-film deodorizers, which are novel equipment developed for steam deacidification of vegetable oils. Here, we highlight issues related to final oil product quality and the corresponding process variables.     

MONITORING OF TRANSESTERIFICATION OF PALM OIL BY DIFFERENTIAL SCANNING CALORIMETRY

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.     

PROCESSING OF CRUDE PALM OIL WITH CERAMIC MICROFILTRATION MEMBRANE

Membrane separation technology offers a potential application in the processing of crude palm oil. Ceramic membranes with different pore diameters (0.45 and 0.2 micron) were used to conduct the study on micromembrane process. Quality parameters of membrane-processed oils examined included free fatty acid (FFA), carotene, fatty acid composition (FAC), phosphorus and iron contents. The effect of operating parameters such as transmembrane pressure, feed flow and time on permeate flux were evaluated. It was found that 'Ceraflo'ceramic membrane with a pore size of 0.45 micron was only able to reject 14% of phosphorus from the crude oil. Ceramic membrane with pore size of 0.2 micron showed a better phosphorus rejection of 56.8%. The permeate was found to contain 7.13 ppm of phosphorus. The 0.2 micron membrane was also able to remove more than 80% of the iron from crude palm oil. Pore sizes for both membranes were not small enough to remove other components such as FFA, and carotene. Both membranes showed a similar trend in which the permeate flux increased with transmembrane pressure and feed flow until a certain limit where the flux declined with increasing pressure and feed flow. The limits in transmembrane pressures for membrane with pore sizes of 0.45 and 0.2 micron were 1.65 and 1.25 bar, respectively. Whereas the limits in feed flow for 0.45 micron and 0.2 micron membranes were 9.2 and 9.8 L/min     

THE ROLE OF MICROBIAL GUMS IN THE COLOR AND CONSISTENCY OF PALM WINE

Viscosity and soluble color changes in palm wine during fermentation were found to show an early increase followed by a gradual decline. Addition of absolute alcohol to palm wine precipitated gums that were absent in the palm sap, indicating production during fermentation. Precipitation of the gum was accompanied by loss in coloration and a significant reduction in viscosity. These properties were regained on reintroduction of the gum showing that the gums were responsible for the properties. Yeasts and bacteria isolated from palm wine were employed in pure culture fermentations of sterile palm sap to determine the origin of the gums. The results showed that the gums were produced mainly by leuconostocs, while two other bacteria not fully identified and a homofermenting Lactobacillus spp. also produced some. Analysis showed the Lactobateriaceae gums to be all glucans, while the gums of the other bacteria were fructans. Palm wine was found to contain both types of gum (80% glucans, 20% fructans), showing that many bacteria produce gums in palm wine concomitantly.     

OPTIMIZATION OF CHEMICAL TRANSESTERIFICATION OF PALM OIL USING RESPONSE SURFACE METHODOLOGY

The effect of catalyst concentration (0.1–0.5% methoxide powder), temperature (50–92C), and time (30–480 min) of chemical transesterification was studied to determine the optimum condition for maximizing concentration of triunsaturated and trisaturated triacylglycerols (TG) in palm oil. TG compositions of the oil were analysed using high-performance liquid chromatography. The optimum condition of the process was determined using statistical response surface methodology. The results showed that the triunsaturated and trisaturated TG responses followed a second order form of the treatments with R²= 0.83 and 0.85, respectively. The triunsaturated TG reached a maximum concentration by using 0.36% catalyst at 78C and 360 min reaction time, whereas the trisaturated TG with 0.36% catalyst at 81C and 325 min reaction time. Considering the two responses, it was concluded that the overall optimum condition could be achieved at 0.36% of catalyst at 78–81C and 325–360 min reaction time. Such conditions increased trisaturated TG in palm oil by 2.34 times and triunsaturated TG by 1.54 times.