Oil Palm Fruit Mesocarp Research Articles

Effect of light intensity on the photo-oxidation stability of red and yellow palm olein mixture

Palm oil is an edible oil derived from the mesocarp of oil palm fruit (Elaeis guineensis), which has a high content of carotenoids and tocopherol components. This research aimed to study the effects of light intensity on the photo-oxidation stability of a red and yellow palm olein mixture. The red and yellow palm oleins were mixed into 100, 200, and 350 ppm carotene content. The photo-oxidation stability of the palm olein mixture was investigated under fluorescent light intensities of 5,000 and 10,000 lux at 31 ±2 °C for 7 days. Changes in the content of chlorophyll, carotene, tocopherols, and peroxide value (PV) were evaluated daily. The results showed that an increase in carotene and tocopherol contents effectively improved the photo-oxidative stability of the palm olein mixture. Degradation of chlorophyll, tocopherols, and increased PV were proportional to light intensity during photo-oxidation. There were no significant changes in carotene content at 5,000 lux light intensity exposure. The degradation rates of chlorophyll and tocopherols can be described as first-order reaction kinetics. In contrast, the increase rate of PV can be described as a zero-order kinetics model with k-values of 6.6 x 10-2, 4.9 x 10-2, 3.7 x 10-2 mequiv.kg-1.h-1, and 8.3 x 10-2, 6.8 x 10-2, and 5.6 x 10-2 mequiv.kg-1.h-1 in palm olein mixture, which contains 100, 200, and 350 ppm carotene at 5,000 and 10,000 lux light intensity exposure, respectively. These results suggested that carotene protected tocopherol in palm olein and that tocopherol and carotene synergistically acted as singlet oxygen quenchers during photo-oxidation.

The Effect of Changing the Nozzle Arrangement in the Vacuum Dryer on Decreasing the Moisture Content of Crude Palm Oil (CPO)

Crude palm oil is obtained from the mesocarp of oil palm fruit through a pressing process. The main cause of the decline in the quality of palm oil is the highwater content. Reducing humidity can be done by optimizing the palm oil dryer or what is called a vacuum dryer. The current vacuum dryers are considered less than optimal because the crude palm oil water content is often high, with the nozzles positioned in a straight line so that the distance between the nozzles is tight. For this reason, research was carried out on the effect of varying the diameter of the nozzle arrangement on reducing crude palm oil water content in vacuum dryers. The research was carried out at different nozzle distances in a vacuum dryer with varying nozzle arrangement diameters of 290 mm, 380 mm, 470 mm, 560 mm, and 650 mm and an inter-nozzle angle of 25.71° from the center of the vacuum dryer tube. This research starts from the design stage, making preliminary models, numerical studies, making prototypes, and experimental studies. From the research carried out on this vacuum dryer, the value of the amount of water vapor volume fraction formation in the vacuum dryer outlet channel for various nozzle arrangement variations was obtained. The total volume fraction of water vapor at a nozzle arrangement diameter of 290 mm is 3.31, a nozzle arrangement diameter of 380 mm is 3.64, a nozzle arrangement diameter of 470 mm is 0.68, a nozzle arrangement diameter of 560 mm is 4.37, and a nozzle arrangement diameter of 650 mm is 4.65. From these results it can be seen that the moisture content is proven to change in each nozzle arrangement and the most optimal decrease in moisture content occurs at a nozzle arrangement diameter of 650 mm as indicated by the formation of the largest volume fraction of water vapor. Based on experiments, it was found that the efficiency of the vacuum drying machine could reach 65.67%.

Design of a separator machine for oil palm fruit mesocarp and nut using computer‐aided design and linear finite element analysis

AbstractThis study addresses the inefficiencies in the current palm oil milling process, where the coexistence of mesocarp fiber and nut during pressing results in oil loss and nut breakage. To tackle this issue, the research aims to develop a machine that can separate mesocarp fibers from nuts before pressing, enhancing oil extraction and quality. The study involves designing the machine layout, creating schematic drawings, wireframe models, and assessing stress and deformation performance. Solidworks simulation was used to determine stress and deformation points within material properties, dimensions, and applied forces. The maximum stress on the rotating disc was 1.44 MPa, with a total deformation of 9.75 x 10−4 mm. Comparing this to the static component strength against cracking (0.093 MPa) revealed that the disc's material and design can safely with stand loads, preventing deformation during the mesocarp and nut separation process. This innovation promises to increase oil yields and improve oil quality in palm oil milling.Practical applicationsThe separation of mesocarp fiber and nuts using centrifugal force is a feasible method. By removing nuts from the mesh (fiber) prior digestion and oil extraction process, the issue of nut breakage will be completely omitted, and thus the pressure can be further increased to maximize oil yield at the palm oil mill industries. This suggested approach has been demonstrated to produce a large amount of oil with minimal broken kernels. The crude palm oil obtained from this separation process also satisfies industrial standards.

Identification and Analysis of MADS-Box Genes Expressed in the Mesocarp of Oil Palm Fruit (Elaeis guineensis Jacq.).

Oil palm (Elaeis guineensis) is the most important tropical oil-bearing crop species worldwide. MADS-box proteins, which play crucial roles in plant growth and development and are involved in various physiological and biochemical processes, compose one of the largest families of plant transcription factors. In this study, 42 MADS-box genes were screened from the mesocarp transcriptome database of oil palm fruit, and their phylogenetic relationships with Arabidopsis thaliana MADS-box genes were analyzed. Based on the results, MADS-box genes from oil palm mesocarp were classified into four groups: MIKCc-type, MIKC*-type, Mα-type, and Mγ-type MADS-box genes. Members of the subfamilies were classified according to the presence of three specific protein motifs. To explore the differential expression of the MADS-box genes, the dynamic expression of all selected MADS-box genes in oil palm was measured by RNA-seq. The high expression of specific MADS-box genes in the mesocarp of oil palm during different developmental stages indicates that those genes may play important roles in the cell division of and metabolite accumulation in the fruit and could become important targets for fruit development and oil accumulation research in oil palm.

EgMYB108 regulates very long-chain fatty acid (VLCFA) anabolism in the mesocarp of oil palm.

EgMYB108 regulates VLCFA anabolism in oil palm. Very long-chain fatty acids (VLCFAs), which are fatty acids with more than 18 C, can not only be used as a form of triglyceride (TAG) but also provide precursors for the biosynthesis of cuticle wax, and they exist in plant epidermal cells in the form of wax in higher plants. However, which and how transcriptional factors (TFs) regulate this process is largely unknown in oil palm. In this study, a MYB transcription factor (EgMYB108) with high expression in the mesocarp of oil palm fruit was characterized. Overexpression of EgMYB108 promoted not only total lipid content but also VLCFA accumulation in oil palm embryoids. Subsequently, transient transformation in protoplasts and qRT-PCR analysis indicated that the EgKCS5 and EgLACS4 genes were significantly increased with the overexpression of EgMYB108. Furthermore, yeast one‑hybrid assays, dual-luciferase assays and EMSAs demonstrated that EgMYB108 binds to the promoters of EgKCS5 and EgLACS4 and regulates their transcription. Finally, EgMYB108 interacts with the promoters of EgLACS and EgKCS simultaneously and finally improves the VLCFA and total lipid contents; a pathway summarizing this interaction was depicted.. The results provide new insight into the mechanism by which EgMYB108 regulates lipid and VLCFA accumulation in oil palm.

Evaluation of fresh palm oil adulteration with recycled cooking oil using GC-MS and ATR-FTIR spectroscopy: A review

Palm oil (PO) is an edible vegetable oil that is extracted from the mesocarp of oil palm fruit (Elaeis guineensis), which is known to contain an almost equal proportion of saturated fatty acids (SFAs) and unsaturated fatty acids (USFAs). PO is used globally, because of its wide application as a frying medium. Extracted from the mesocarp of the oil palm fruit, PO needs to be processed to make it of edible quality. However, to meet growing global demand, it is often adulterated with recycled cooking oil (RCO), which is of inedible quality. As the methods of fresh palm olein (FPO) adulteration are sophisticated, it created an urgent need for commensurate analytical techniques with which to detect FPO adulteration. As such, chromatography and spectroscopy are commonly used to detect adulterations in edible oil. Therefore, this study evaluated the efficacy of utilising gas chromatography-mass spectrometry (GC-MS) and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy to detect the adulteration of FPO with inedible RCO. Although previous studies attest to the efficacy of utilising GC-MS and ATR-FTIR spectroscopy in adulteration detection, both these techniques only provided specific qualitative and quantitative insights into the compounds present in oil samples. As such, further extensive studies on the application of a variety of adulteration detection methods are needed to provide regulatory authorities with information on the reliability of these modern adulteration detection methods.

The Impact of Different Drying Techniques on the Physicochemical and Quality Characteristics of Oil Palm Fruit Mesocarp (Elaeis guineensis).

Drying is one of the traditional means of preserving food. However, various drying methods can influence the nutritional and bioactive constituents of the food product. This study is aimed at evaluating the effect of different drying methods on the proximate composition, physicochemical properties, and minor constituents of palm oil fruit mesocarp. Two varieties of fresh oil palm fruit (dura and tenera) were processed to separate the mesocarp from the other part of the fruit. The fresh fruit mesocarp was divided into five groups and subjected to different drying methods. Proximate and physicochemical characteristics of the oil palm fruit mesocarp were determined. The dried mesocarp had low moisture content (1.49-3.28%), high crude fat content (78.10-90.60%), carbohydrate (4.41-15.12%), crude protein (0.93-3.40%), and ash (0.53-1.15%). The free fatty acid (FFA) (1.06-3.54) and acid value (AV) (2.17 to 8.83 mgKOH/g) were lower because the samples were heated at 100°C for 30 min. The lower pH, FFA, AV, titratable acidity, moisture content, and high antioxidant activity of the oil palm fruit products could be an indication of shelf stability against microbial contamination and rancidity.

EgmiR5179 Regulates Lipid Metabolism by Targeting EgMADS16 in the Mesocarp of Oil Palm (Elaeis guineensis).

EgMADS16, one of the MADS-box transcription factors in oil palm, has a high expression level in the late fruit development of the oil palm fruit mesocarp. At the same time, it is also predicted to be the target gene of EgmiR5179, which has been identified in previous research. In this paper, we focused on the function and regulatory mechanism of the EgMADS16 gene in oil palm lipid metabolism. The results indicated that the transcription level of EgMADS16 was highest in the fourth stage, and a dual-luciferase reporter assay proved that the EgMADS16 expression level was downregulated by EgmiR5179. In both the OXEgMADS16 Arabidopsis seeds and oil palm embryonic calli, the total lipid contents were significantly decreased, but the contents of C18:0 and C18:3 in OXEgMADS16 lines were significantly increased. As expected, EgmiR5179 weakened the inhibitory effect of EgMADS16 on the oil contents in transgenic Arabidopsis plants that coexpressed EgmiR5179 and EgMADS16 (OXEgmiR5179-EgMADS16). Moreover, yeast two-hybrid and BiFC analyses suggested that there was an interaction between the EgMADS16 protein and EgGLO1 protein, which had been proven to be capable of regulating fatty acid synthesis in our previous research work. In summary, a model of the molecular mechanism by which miRNA5179 targets EgMADS16 to regulate oil biosynthesis was hypothesized, and the research results provide new insight into lipid accumulation and molecular regulation in oil palm.

Genomic structure, QTL mapping, and molecular markers of lipase genes responsible for palm oil acidity in the oil palm (Elaeis guineensis Jacq.)

The degradation of triglycerides in oil palm fruit due to an endogenous lipase in the pulp is the main reason for acidification of palm oil, which causes major economic losses and is currently mainly associated with the FLL1 gene. We designed this study to identify all the major genes controlling differences in acidity and lipase activity in the oil palm fruit mesocarp and determine a molecular markers kit to allow marker-assisted selection of commercial varieties with low acidity. Not only one gene (FLL1) but three closely linked genes including FLL1 were found and characterized in LM2T_EgCIR184O12c, a bacterial artificial chromosome sequence of 231 kb. Intra-gene PCR-based markers were designed for these genes. A QTL gene co-localization analysis for oil acidity (percentage of fatty acids released) was performed on two mapping populations. It evidenced a single major QTL at our lipase gene loci, explaining 84 to 92% of phenotypic variation, and validating the main genetic control of palm oil acidification by FLL1 and/or by the two new lipase genes. The three lipase genes had high homology to demonstrated triacylglycerol lipases. While FLL1 shows the highest expression levels, the two other genes may also contribute to oil acidity. Our molecular markers of lipase genes and the associated major QTL is an important step towards marker-assisted selection of commercial varieties with low acidity.

Differential abundance analysis of mesocarp protein from high- and low-yielding oil palms associates non-oil biosynthetic enzymes to lipid biosynthesis.

BackgroundThe oil palm Elaeis guineensis Jacq. which produces the highest yield per unit land area of the oil crops is the most important commercial oil crop in South East Asia. The fleshy mesocarp of oil palm fruit, where oil is mostly derived from, contains up to 90 % dry weight of oil (one of the most concentrated in plant tissues). Hence, there is attention given to gain insights into the processes of oil deposition in this oil rich tissue. For that purpose, two-dimensional differential gel electrophoresis (DIGE) coupled with western assays, were used here to analyze differential protein levels in genetically-related high-and low-yielding oil palm mesocarps.ResultsFrom the DIGE comparative analysis in combination with western analysis, 41 unique differentially accumulated proteins were discovered. Functional categorization of these proteins placed them in the metabolisms of lipid, carbohydrate, amino acids, energy, structural proteins, as well as in other functions. In particular, higher abundance of fructose-1,6-biphosphate aldolase combined with reduced level of triosephosphate isomerase and glyceraldehyde-3-phosphate dehydrogenase may be indicative of important flux balance changes in glycolysis, while amino acid metabolism also appeared to be closely linked with oil yield.ConclusionsForty-one proteins in several important biological pathways were identified as exhibiting differential in abundance at critical oil production stages. These confirm that oil yield is a complex trait involving the regulation of genes in multiple biological pathways. The results also provide insights into key control points of lipid biosynthesis in oil palm and can assist in the development of genetic markers for use in oil palm breeding programmes.Electronic supplementary materialThe online version of this article (doi:10.1186/s12953-015-0085-2) contains supplementary material, which is available to authorized users.

Hormones, Polyamines, and Cell Wall Metabolism during Oil Palm Fruit Mesocarp Development and Ripening

Oil palm is one of the most productive oil-producing crops and can store up to 90% oil in its fruit mesocarp. Oil palm fruit is a sessile drupe consisting of a fleshy mesocarp from which palm oil is extracted. Biochemical changes in the mesocarp cell walls, polyamines, and hormones at different ripening stages of oil palm fruits were studied, and the relationship between the structural and the biochemical metabolism of oil palm fruits during ripening is discussed. Time-course analysis of the changes in expression of polyamines, hormones, and cell-wall-related genes and metabolites provided insights into the complex processes and interactions involved in fruit development. Overall, a strong reduction in auxin-responsive gene expression was observed from 18 to 22 weeks after pollination. High polyamine concentrations coincided with fruit enlargement during lipid accumulation and latter stages of maturation. The trend of abscisic acid (ABA) concentration was concordant with GA₄ but opposite to the GA₃ profile such that as ABA levels increase the resulting elevated ABA/GA₃ ratio clearly coincides with maturation. Polygalacturonase, expansin, and actin gene expressions were also observed to increase during fruit maturation. The identification of the master regulators of these coordinated processes may allow screening for oil palm variants with altered ripening profiles.

Isolation and expression analysis of transcripts encoding metallothioneins in oil palm

Two of the abundant transcripts encoding type 2 metallothionein (MT) proteins designated as MET2a and MET2b were selected in our previous study due to their high abundance (16.05 %) in the suppression subtractive hybridization library and their involvement in fruit development and maturation. The present study involves the isolation of the full-length cDNA encoding MET2a and MET2b from the ripening oil palm fruit mesocarp, examining their expression pattern compared to the other two previously reported type-3 MT members (MT3-A and MT3-B) in various oil palm organs including different vegetative and reproductive tissues. The full-length cDNA sequences of MET2a and MET2b were 571 and 553 bp and they were designated as EgMT2a and EgMT2b, respectively. The sequences of the EgMT2a and EgMT2b were then compared for sequence similarities in the database using both BLASTN and BLASTX programs. Their sequences were homologous (67-77 %) with several type-2 MTs in plants. All four MT encoding genes were differentially expressed in the ripening oil palm mesocarp tissues, but undetectable in the vegetative tissues examined. All MT genes examined were significantly up-regulated in the mature developmental stages of oil palm fruit mesocarp, except for EgMT2b which was expressed only at 17 weeks after anthesis. The type 2 MT proteins are related to a greater degree to the late fruit-ripening stage than the type 3 MT proteins consistent with their reported functions in homeostasis or detoxification. The findings in the present study contribute to better understanding the molecular mechanisms involved in fruit ripening in oil palm.

Proteomic Analysis of the Oil Palm Fruit Mesocarp Reveals Elevated Oxidative Phosphorylation Activity is Critical for Increased Storage Oil Production

Palm oil is a highly versatile commodity with wide applications in the food, cosmetics, and biofuel industries. Storage oil in the oil palm mesocarp can make up a remarkable 80% of its dry mass, making it the oil crop with the richest oil content in the world. As such, there has been an ongoing interest in understanding the mechanism of oil production in oil palm fruits. To identify the proteome changes during oil palm fruit maturation and factors affecting oil yield in oil palm fruits, we examined the proteomic profiles of oil palm mesocarps at four developing stages--12, 16, 18, and 22 weeks after pollination--by 8-plex iTRAQ labeling coupled to 2D-LC and MALDI-TOF/TOF MS. It was found that proteins from several important metabolic processes, including starch and sucrose metabolism, glycolysis, pentose phosphate shunt, fatty acid biosynthesis, and oxidative phosphorylation, were differentially expressed in a concerted manner. These increases led to an increase in carbon flux and a diversion of resources such as ATP and NADH that are required for lipid biosynthesis. The temporal proteome profiles between the high-oil-yielding (HY) and low-oil-yielding (LY) fruits also showed significant differences in the levels of proteins involved in the regulation of the TCA cycle and oxidative phosphorylation. In particular, the expression level of the β subunit of the ATP synthase complex (complex IV of the electron transport chain) was found to be increased during fruit maturation in HY but decreased in the LY during the fruit maturation. These results suggested that increased energy supply is necessary for augmented oil yield in the HY oil palm trees.

Improving palm oil quality through identification and mapping of the lipase gene causing oil deterioration

The oil palm fruit mesocarp contains high lipase activity that increases free fatty acids and necessitates post-harvest inactivation by heat treatment of fruit bunches. Even before heat treatment the mesocarp lipase activity causes consequential oil losses and requires costly measures to limit free fatty acids quantities. Here we demonstrate that elite low-lipase lines yield oil with substantially less free fatty acids than standard genotypes, allowing more flexibility for post-harvest fruit processing and extended ripening for increased yields. We identify the lipase and its gene cosegregates with the low-/high-lipase trait, providing breeders a marker to rapidly identify potent elite genitors and introgress the trait into major cultivars. Overall, economic gains brought by wide adoption of this material could represent up to one billion dollars per year. Expected benefits concern all planters but are likely to be highest for African smallholders who would be more able to produce oil that meets international quality standards.

Gene expression of the oil palm transcription factor EgAP2-1 during fruit ripening and in response to ethylene and ABA treatments

A cDNA encoding an ERE-binding protein (EgAP2-1) was isolated from the oil palm fruit mesocarp treated with ethylene using yeast one-hybrid assay. EgAP2-1 belongs to the AP2 subfamily of the APETALA2/ethylene-responsive factor (AP2/ERF) proteins and contains two highly conserved AP2/EREBP DNA-binding domains (DNA-BD). Sequence comparison of EgAP2-1 with other AP2 proteins revealed high conservation of the two AP2/EREBP domains and linker region among these proteins. Its protein was localized to the nucleus of onion epidermis cells and showed ERE-specific binding, transcriptional activation, and transactivation properties in yeast and in vitro. Its mRNA was highly expressed in oil palm mesocarp with elevated levels in ripening fruits but not in leaves and roots. EgAP2-1 was induced in mesocarp in response to ethylene and abscisic acid but not other hormonal stimuli, including methyl jasmonate and salicylic acid, and abiotic stresses including drought, cold, and high-salinity. Our results demonstrate a link between the regulation of EgAP2-1 expression and ethylene- and/or ABA-coordinated control of the fruit ripening and suggest a regulatory role for EgAP2-1 during fruit ripening and development in oil palm.

Regulatory Mechanisms Underlying Oil Palm Fruit Mesocarp Maturation, Ripening, and Functional Specialization in Lipid and Carotenoid Metabolism

Fruit provide essential nutrients and vitamins for the human diet. Not only is the lipid-rich fleshy mesocarp tissue of the oil palm (Elaeis guineensis) fruit the main source of edible oil for the world, but it is also the richest dietary source of provitamin A. This study examines the transcriptional basis of these two outstanding metabolic characters in the oil palm mesocarp. Morphological, cellular, biochemical, and hormonal features defined key phases of mesocarp development. A 454 pyrosequencing-derived transcriptome was then assembled for the developmental phases preceding and during maturation and ripening, when high rates of lipid and carotenoid biosynthesis occur. A total of 2,629 contigs with differential representation revealed coordination of metabolic and regulatory components. Further analysis focused on the fatty acid and triacylglycerol assembly pathways and during carotenogenesis. Notably, a contig similar to the Arabidopsis (Arabidopsis thaliana) seed oil transcription factor WRINKLED1 was identified with a transcript profile coordinated with those of several fatty acid biosynthetic genes and the high rates of lipid accumulation, suggesting some common regulatory features between seeds and fruits. We also focused on transcriptional regulatory networks of the fruit, in particular those related to ethylene transcriptional and GLOBOSA/PISTILLATA-like proteins in the mesocarp and a central role for ethylene-coordinated transcriptional regulation of type VII ethylene response factors during ripening. Our results suggest that divergence has occurred in the regulatory components in this monocot fruit compared with those identified in the dicot tomato (Solanum lycopersicum) fleshy fruit model.

Fungal colonization of rice straw and palm press fibre in the rumen of cattle and buffalo

Fungal colonization and development in rice straw and palm press fibre (mesocarp of oil palm fruit after the extraction of oil) were very similar in both cattle and buffalo. In both animal species, attachment to rice straw by rumen fungal zoospores was rapid, within 15 min of rumen incubation. At 6 h of rumen incubation, thin- and thick-walled tissues were colonized by fungal hyphae and by 24 h fungal colonization was extensive. Fungi were predominantly those with spherical and ovoid sporangia. Fusiform sporangia were in fewer numbers. Fungal colonization was also extensive at 48 and 72 h. The colonization and development of the fungi on the palm press fibre, both untreated and treated with ammonium hydroxide and ether, was slow.

Histological localization of oil palm fruit lipase

Development of free fatty acids (FFA) and subsequent deterioration of palm oil quality can be attributed to lipase, an active hydrolytic enzyme present in the mesocarp of oil palm fruit. A histochemical method was used to localize this enzyme in the mesocarp. FFA released from endogenous glycerides were precipitated as lead salt. The deposits were located on the membranes of oil bodies. Enzymatic activity in the mesocarp was also studied under different conditions of fruit storage: ambient temperature, freezing, etc. The enzyme was active after freezing but less active under ambient conditions of fruit storage. Investigations on fruit development indicated that the enzyme activity started appearing between 16–20 weeks after anthesis (WAA) which synchronized with the beginnning of lipid formation. These histochemical studies were supported wity biochemical data on FFA.

Changes in lipid class and fatty acid composition during maturation of mesocarp of oil palm (Elaeis guineensis) variety dura

AbstractThe deposition of oil, major lipid classes, and the constituent fatty acids of the oil palm fruit mesocarp were investigated to gain a better insight into the accumulation of these components. The oils were extracted with chloroform‐methanol 1:2 (v/v) and were fractionated by silicic acid column chromatography into classes. Fatty acids were analysed by gas‐liquid chromatography. Shortly after anthesis, lipids, mainly phospho‐ and glyco‐lipids, were a small proportion of the mesocarp. With time the lipid content increased, until at maturity it accounted for about 60% of fresh mesocarp weight. Approximately 97% of the lipid at maturity was neutral lipid, essentially triacylglycerol. Maximum oil quantity was obtained at 22 weeks after anthesis. The active lipid accumulation period was from weeks 18 to 22 after pollination. Contrary to previously published data, palmitic, oleic and linoleic acids were characteristically present at all stages of oil accumulation. Linolenic acid was present in the neutral lipids from immature mesocarp of the oil palm fruit, but was probably diluted out in mature palms. Appreciable amounts of linolenic acid were present in the polar lipid fractions.

Partial purification and some properties of the lipase present in oil palm (Elaeis guineensis) mesocarp

AbstractThe fatty layer obtained by centrifuging a homogenate of oil palm fruit mesocarp contains an active lipase. The lipase which was partially purified using a combination of ammonium sulphate fractionation, ion exchange and gel filtration chromatography, indicated an optimum activity at pH 4.5 and a temperature of 30°C. The enzyme exhibited good activity towards its natural substrate, palm oil as well as glycerol trioleate and glycerol tripalmitate. It also showed a linear reaction rate for the first 20 min of incubation. Sodium cyanide, resorcinol, cholesterol, lecithin and glycylglycine strongly inhibited its activity while phenol, L‐cysteine and EDTA enhanced its activity. It is suggested that the lipase is associated with the membrane of the oil droplets.