High Oleic Palm Oil Research Articles

Study of the changes in molecular composition of high‒oleic palm oil (Coari × La Mé) before and after physical refining

High‒oleic palm oil (HOPO) is a lipid substrate rich in biologically valuable substances. However, standard physical refining procedures result in a medium‒to‒large‒scale loss of beneficial nutritional properties. This study reports, for the first time, on the primary phytochemicals contained in HOPO before and after physical refining and the antioxidant potential of HOPO and its refined fractions, including byproducts. The composition of these compounds was elucidated using attenuated total reflection‒Fourier Transform infrared spectroscopy and gas chromatography with flame ionization detection analysis. HOPO and HOPO distilled fatty acids (HOPO‒FAD) had the highest vitamin E (1,026.34 and 6,700.13 mg kg−1, respectively) and phenolic compounds (66.24 and 176.50 mg·GAE·kg−1, respectively) contents and showed the highest percentage DPPH• inhibition (77.85% and 97.19%, respectively). If valuable phytochemicals are preserved, HOPO and HOPO‒FAD may be promising sources of functional ingredients for use in the food, pharmaceutical, and nutraceutical industries.

Effect of wall material on lipophilic functional compounds of high oleic palm oil emulsions encapsulated by Refractance Window drying

High-oleic palm oil is a food-grade oil with desirable properties, as it is characterised by having an oleic acid concentration above 50 % and a high vitamin E and provitamin A content. This study investigated the effect of different combinations of two wall materials (whey protein (WP) and Capsul®, a commercial octenyl succinic anhydride modified starch (OSA-MS)) on the concentration of provitamin A, vitamin E and oleic acid, and the physical properties of high oleic palm oil emulsions encapsulated by Refractance Window drying technology. Wall material composition significantly affected (p < 0.05) all response variables, and R2 values were above 0.75 for all responses. Phytonutrient preservation showed its highest at an OSA-MS: WP concentration ratio of 1: 3. Optimal results were achieved (minimum moisture content, water activity and hygroscopicity, and maximum encapsulation efficiency and phytonutrient preservation) at an OSA-MS concentration of 8.13 % and WP concentration of 91.87 %. Flakes were obtained as a solid structure that protects oil's phytonutrients with 94 %, 75 % and 87 % of preservation of oleic acid, vitamin E and carotenoids, respectively. It shows that the wall material combination and encapsulation technique are suitable for obtaining lipophilic functional compounds.

Thermomechanical Properties of High Oleic Palm Oil Assessed Using Differential Scanning Calorimetry, Texture Analysis, Microscopy, and Shear Rheology.

Standard Palm Oil (SPO) is widely used as a food ingredient partially due to its unique thermophysical properties. However, the American Heart Association recommends a saturated fat consumption of <5% of the caloric intake per day. The OxG Palm hybrid yields oil known as "palm oil with a higher content of oleic acid" (HOPO), with <35% SFA and >50% oleic acid. Characterizing novel high oleic oils is the starting point to find processes that can functionalize them such as oleogelation. This study compared the thermophysical properties of HOPO to SPO using Differential Scanning Calorimetry, shear rheology, polarized light microscopy, and texture analysis to characterize the differences between these oils. HOPO had a lower onset crystallization temperature (Δ7 °C) and its rheological behavior followed similar trends to SPO; however, large viscosity offsets were observed and were correlated to differences in crystallization temperatures. The maximum peak force of SPO was an order of magnitude higher than that of HOPO. Overall similar trends between the oils were observed, but differences in firmness, crystal morphology, and viscosity were not linearly correlated with the offset in crystallization temperature. This study quantified differences between these oils that will better enable industry to use HOPO in specific applications.

The Effects of Emulsifier Addition on the Functionalization of a High-Oleic Palm Oil-Based Oleogel.

Alternatives to oils with high saturated fatty acid content are often liquid oils (high in unsaturated fatty acids) that have a modified structure created either through additives or processing. Emulsifiers are additives that can be used as structuring agents of liquid fats; this process results in products such as oleogels, which can broaden the applications of these oils. This study assessed and compared the effects of mono- and diglycerides at 3%, 5%, 7% and 10% w/w on the mechanical and thermal properties of high-oleic palm oil (HOPO) oleogels. HOPO was heated to 75 °C and mixed with mono- or diglycerides at those four concentrations. The thermomechanical properties of the melted oleogels were assessed using differential scanning calorimetry (DSC). The melted oleogels were cooled to final temperatures of 5 °C, 10 °C and 15 °C under identical cooling rates, after which a puncture test (via a texture analyzer) was used to assess their textures. Finally, polarized light microscopy was used to assess the mechanical changes induced through emulsifier addition. The results showed that the use of mono- and diglycerides significantly modified the thermal and mechanical properties of the oleogels. The addition of saturated monoglycerides promoted a higher-temperature nucleation stage that did not previously occur in HOPO. The onset crystallization temperature increased with the addition of diglycerides, promoting crystallization at higher temperatures of the high-melting fraction of HOPO. The hardness of the oleogel generally increased with emulsifier addition and a reduction of the temperature. The effect of the temperature on the hardness was significantly greater in the diglyceride oleogel than in the monoglyceride oleogel. This study shows that the addition of mono- and diglycerides allows companies to customize their formulations to achieve desired results that may not previously have been possible, thereby facilitating novel uses for these oils within the industry.

Natural Oil Polyol from High-Oleic Palm Oil─Reaction Kinetics and Monitoring Using Near-Infrared Spectroscopy

Natural oil polyols are widely used biobased monomers for the manufacture of polymers and resins. They are mainly produced via hydroxylation of epoxidized vegetable oils. This work studied the kinetics of hydroxylation of epoxidized high-oleic palm oil via oxirane ring cleavage with ethylene glycol (EG). Experiments were performed at different temperatures (65–95 °C), hydroxyl-to-oxirane mol ratios (1.75–14), and catalyst loadings (H2SO4, 0.5–4% wt). The reaction was monitored by measuring the hydroxyl value and oxirane oxygen content in samples using near-infrared absorbance. Different power-law kinetic expressions were evaluated, and the lower average error (3.25%) resulted in first order with respect to epoxide, second order with respect to EG, and considering oligomers formation. The corresponding frequency factor and energy of activation for hydroxylation were 3.58 × 104 and 51.9 kJ/mol, and those for oligomerization were 3.32 × 105 and 67.2 kJ/mol, respectively. The obtained model is suitable for further process design and scale up.

Kinetic study on the production of biodegradable lubricant by enzymatic transesterification of high oleic palm oil

Kinetic studies are necessary to identify inhibitors of lipase enzyme deactivation in reaction systems because varying substrate concentrations can affect the enzyme's catalytic activity. The present study aimed to analyze the reaction kinetics of palm-based polyol ester production catalyzed by commercial lipase Novozyme 435 (N435). The enzymatic transesterification reaction was performed in a solvent-free medium. The effect of substrates concentration, specifically high oleic palm methyl ester (HO-PME) and trimethylolpropane (TMP), on the kinetic constant was studied at the initial reaction rate. The study was conducted based on the Ping-pong Bi-bi model, assuming that both substrates could inhibit the reaction. The reaction was carried out at 70 °C and 15.25 mbar with a 3 % (w/w) N435 enzyme load to investigate the effect of various HO-PME and TMP concentrations. The kinetic constants obtained are as follows: Km(HOPME) = 61.112 mol/L, Km(TMP) = 0.336 mol/L, Ki(HOPME)= 0.002 mol/L, Ki(TMP) = 2.415 mol/L and Vmax = 17.24 mol/L.hr. The results implied that N435 has higher affinity towards TMP than HO-PME. Inhibition constant indicated a lower inhibitory function of the TMP than HO-PME (Ki(TMP) >Ki(HOPME)). The reaction kinetics obtained in this study agreed well with the model used with TMP and HO-PME as competitive inhibitor during enzymatic transesterification.

Evaluation of the Survival of Lactobacillus fermentum K73 during the Production of High-Oleic Palm Oil Macroemulsion Powders Using Rotor-Stator Homogenizer and Spray-Drying Technique.

This study aimed to evaluate the survival of the probiotic Lactobacillus fermentum when it is encapsulated in powdered macroemulsions to develop a probiotic product with low water activity. For this purpose, the effect of the rotational speed of the rotor-stator and the spray-drying process was assessed on the microorganism survival and physical properties of probiotic high-oleic palm oil (HOPO) emulsions and powders. Two Box-Behnken experimental designs were carried out: in the first one, for the effect of the macro emulsification process, the numerical factors were the amount of HOPO, the velocity of the rotor-stator, and time, while the factors for the second one, the drying process, were the amount of HOPO, inoculum, and the inlet temperature. It was found that the droplet size (ADS) and polydispersity index (PdI) were influenced by HOPO concentration and time, ζ-potential by HOPO concentration and velocity, and creaming index (CI) by speed and time of homogenization. Additionally, HOPO concentration affected bacterial survival; the viability was between 78-99% after emulsion preparation and 83-107% after seven days. The spray-drying process showed a similar viable cell count before and after the drying process, a reduction between 0.04 and 0.8 Log10 CFUg-1; the moisture varied between 2.4% and 3.7%, values highly acceptable for probiotic products. We concluded that encapsulation of L. fermentum in powdered macroemulsions at the conditions studied is effective in obtaining a functional food from HOPO with optimal physical and probiotic properties according to national legislation (>106 CFU mL-1 or g-1).

Micronutrient retention in high oleic palm oil: effect of refining technique

SummaryRetention of micronutrients in high oleic palm oil (HOPO) was evaluated by comparing two methods; standard refining (260 °C) and modified refining (160, 180, 200 °C). Tocopherol analysis showed that α‐tocopherol loss during standard refining was relatively low for both refined bleached and deodorised (RBD) PO control (10%) and RBDHOPO (2%). On the contrary, the carotene loss for both RBDPO control and RBDHOPO in standard refining methods was 99% (1.9 and 5.9 ppm, detected). Modified refining temperatures, can maintain up to 99% more carotenes than standard refining. Applying modified refining to RBDHOPO retains ~78%–83% more carotene than regular RBDPO. This examination shows, suitably processed RBDHOPO has the capability for producing a red palm oil (RPO), enriched with carotenoid for provitamin A function.

Kinetics Study on the Production of Biodegradable Lubricant by Enzymatic Transesterification of High Oleic Palm Oil

Kinetics Study on the Production of Biodegradable Lubricant by Enzymatic Transesterification of High Oleic Palm Oil

Experimental optimization during epoxidation of a high-oleic palm oil using a simplex algorithm

This work explored the epoxidation of high oleic palm oil (HOPO) extracted from recently developed palm tree hybrids. The process was carried out by reaction with 50 % wt·H2O2 using peracetic acid generated in-situ as oxygen carrier, and H2SO4 as catalyst. The study focused on the optimization of the operating conditions to maximize the productivity of oxirane groups in the epoxidized oil, considering the conversion of unsaturated groups and the selectivity to oxirane ring. The optimization was done by experimental application of a simplex algorithm varying reaction temperature (55–70 °C), catalyst loading (1–5 % wt.), mol ratio of H2O2 to HOPO unsaturations (1−10), acetic acid loading with respect to HOPO (2–10 % wt.), and reaction time (1–6 h). Optimal conditions were obtained after eight experimental steps, reaching a conversion of oil’s unsaturations of nearly 90 %, with a selectivity towards oxirane groups of 88.6 %. The obtained oil had an oxygen oxirane content of 3.48 %wt., which corresponded to ~80 % of theoretical yield. The optimal conditions were tested in a subsequent kinetic experiment, and the results were reproduced obtaining an epoxy number of 3.5 and a yield of 79.7 %. This methodology can also be used to assess novel epoxidation catalysts.

Oxidative stability of Moringa oleifera seed oil: Effect of degumming and deodorization on tocopherol retention

AbstractMoringa oleifera seed oil (MSO) from Lombok was extracted by n‐hexane and evaluated after refining by several degumming methods to understand the impact of individual tocopherol retention and compared to extra virgin olive oil (EVOO) and high oleic palm oil (HOPO). MSO achieved an Oxidative Stability Index (15.8 h); EVOO (11.7 h) HOPO (8.83 h), based on two factors; the degree of unsaturation and total tocopherols, which did not accurately correlate with oxidation stability. The presence of tocopherol type affected the efficiency of heat stability in MSO, which is caused by a significant level of δ‐tocopherol (13.5 ppm), which was retained, through effective water degumming. Whereas, δ‐tocopherol in EVOO was not detected. This strongly suggests δ‐tocopherol contributes effectively against heat oxidation and thereby improved the overall stability of MSO.Novelty impact statementSeveral novelties are identified in this work, which at the time, could not be found within the literature: first, the type of phosphatide in Moringa Oleifera is in hydratable form. Hence, secondly, we propose the appropriate degumming method for Moringa Oleifera seed oil is by water degumming. And third, the particular tocopherol type most impacting the oxidative stability performance of Moringa Oleifera was identified as δ‐tocopherol.

Oxidative stability of high oleic palm and hazelnut skin oil blends

AbstractHigh oleic palm oil (HOPO) with high oleic and palmitic acid contents is a new vegetable oil that needs to find further use in food applications, while hazelnut skin oil (HSO) with high oleic acid content is a by‐product of hazelnut oil production and have no commercial value. The aim of the study was to obtain new oil blends for new food formulations with high oxidative stability and low (or reasonable) saturated fatty acid content using HOPO and HSO. For this aim, they were blended in the proportions of 0 to 100% (wt/wt), and fatty acid and tocol compositions, induction period and storage stability of the blends were evaluated. Tocotrienols (560.94 mg/kg) constitute the majority of the tocol content of HOPO, while tocopherols (437.69 mg/kg) were the major tocols of HSO. HOPO has a higher saturated fatty acid composition and lower monounsaturated fatty acids content than HSO. In general, it was determined that increasing the HSO ratio in oil blends reduced their oxidative stabilities, which is most likely because HSO is richer in total unsaturated fatty acids (91.8%) than HOPO (68.4%). In addition, tocotrienols are known to be stronger antioxidants than tocopherols. Although HOPO is rich in γ‐tocotrienol, which has a strong antioxidant activity, it also has some disadvantages such as having a high price and containing significant levels of saturated fatty acids (mainly palmitic acid). The optimum blend ratio was then determined as 50% HOPO:50% HSO considering oxidative stability and fatty acid compositions.

Use of High Oleic Palm Oils in Fluid Shortenings and Effect on Physical Properties of Cookies

Quality characteristics of bakery products rely partially on the amount and type of fats in their formulation. This study focused on producing emulsified shortenings with high oleic palm oil fractions to be thermo-mechanically characterized and used in the baking of high-fat cookies. Palm oil and hydrogenated fats were commonly used in bakery shortenings to achieve texture and flavor. However, saturated and trans-fats have been shown to cause detrimental health effects, motivating their replacement by unsaturated fats. High oleic palm oil (HOPO) is a novel oil with lower saturated fat and higher oleic acid compared to traditional palm oil (TPO). High oleic red olein (HORO) is a carotene-rich fraction of HOPO. Emulsified shortenings with 30% saturated fat containing HOPO, HORO, and TPO were produced. All shortenings resulted in similar onset temperatures of crystallization and melting points through DSC. Mid-melting peaks observed on TPO where absent in HOPO and HORO shortenings, reflected in lower hardness and calculated SFC of HOPO and HORO shortenings vs. TPO shortening. However, physical properties of shortening-containing cookies were not statistically different. It was demonstrated how HOPO and HORO can be used as alternative fats to TPO in the making of shortenings to be used in baking applications.

Compound distribution, structural analysis and nanomechanical properties of nanofibers loaded with high-oleic palm oil nanoemulsions for packaging application

The effect of the HOPO concentration on the morphology, fiber diameter, oil load and distribution, protein structure, protein-oil colocalization, and nanomechanical properties of the NFs were evaluated. We obtained smooth and defect-free NFs with diameters in range of 77–94 nm. Fourier-transform infrared spectroscopy was used as a reliable method to confirm oil load and protein structure after electrospinning. β-turn, β-sheet, α-helix, and triple helical structures were quantified. Confocal laser scanning microscopy was used to analyze colocalization, and results revealed a high distribution of NE droplets along the NFs and high oil-protein colocalization (overlap coefficient of ~ 0.63). The nanomechanical properties of the NE-loaded NFs demonstrated that at higher HOPO concentrations, the elastic modulus decreased. Likewise, homogeneity and synergy between compounds were observed. The adhesion properties of NE-loaded NFs were associated with their sticky surface, which was attributed to presence of HOPO. The NE-loaded NFs presented suitable physical properties for edible packaging.

The effect of process variables on the physical properties and microstructure of HOPO nanoemulsion flakes obtained by refractance window

Refractance window (RW) drying is considered an emerging technique in the food field due to its scalability, energy efficiency, cost and end-product quality. It can be used for obtaining flakes from high-oleic palm oil (HOPO) nanoemulsions containing a high concentration of temperature-sensitive active compounds. This work was thus aimed at studying the effect of temperature, thickness of the film drying, nanoemulsion process conditions, and emulsion formulation on the flakes’ physical properties and microstructure. The results showed that HOPO flakes had good physical characteristics: 1.4% to 5.6% moisture content and 0.26 to 0.58 aw. Regarding microstructure, lower fractal dimension (FDt) was obtained when RW drying temperature increased, which is related to more regular surfaces. The results indicated that flakes with optimal physical properties can be obtained by RW drying of HOPO nanoemulsions.

The effect of composition, microfluidization and process parameters on formation of oleogels for ice cream applications

The use of oleogels is an innovative and economical option for the technological development of some food products, among them ice creams. The aim of this study was to establish the best processing conditions to obtain an emulsion which form oleogels with the lowest ζ-potential and average droplet size (ADS) for use as ice cream base. Using surface response methodology (SRM), the effects of three numerical factors (microfluidization pressure, oil and whey protein concentration, WP) and four categorical factors (oil type, temperature, surfactant, and type of WP) on formation of emulsions were assessed. The response variables were ζ, ADS, polydispersity index (PDI), viscosity (η), hardness, cohesiveness and springiness. Additionally, a numerical optimization was performed. Two ice creams containing milk cream and oleogel, respectively were compared under the optimization conditions. Results suggest oleogels obtained from the microfluidization of whey and high oleic palm oil are viable for the replacement of cream in the production of ice cream.

High-Oleic Palm Oil (HOPO) Production from Parthenocarpic Fruits in Oil Palm Interspecific Hybrids Using Naphthalene Acetic Acid

Interspecific OxG hybrids of African palm Elaeis guineensis Jacq. and the American palm Elaeis oleifera Cortes produce high-oleic palm oil (HOPO) with low saturated fatty acid content. OxG hybrids are highly productive, grow slowly, and are resistant to bud rot disease. However, OxG hybrid pollen presents low viability and germinability, so assisted pollination is a must. Hybrids can produce parthenocarpic or seedless fruits, with the exogenous application of plant growth regulators. Thus, naphthalene acetic acid (NAA) effects on parthenocarpic fruits induction, bunch formation, and oil quality were evaluated. The OxG hybrid Coari x La Mé was used. NAA doses, frequency, number of applications, and the phenological stages for the treatments were defined. A total dose of 1200 mg L−1 NAA applied three or four times produced bunches with better fruit set, similar average bunch weight, and oil to dry mesocarp than those obtained with assisted pollination. At a semi-commercial scale, 1200 mg L−1 NAA induced bunches that consisted of 93% or more of seedless fruits. Bunch number (2208 ± 84 versus 1690 ± 129) and oil to bunch (32.2 ± 0.7 versus 25.3 ± 0.8) were higher in the NAA induced bunches than in the assisted pollination. However, the average bunch weight was lower (12.2 ± 0.4 versus 14.9 ± 0.6). NAA increased oil to bunch in 36% (8.7 ± 0.1 versus 6.4 ± 0.3). Thus, with this technology, it is plausible to reach more than 10 tons per hectare per year of HOPO. Potentially, without increasing the planted oil palm area, OxG hybrids and NAA applications could alone meet the world’s fats and oil demands.

High Oleic Pentaerythritol Tetraester Formation via Transesterification: Effect of Reaction Conditions

Pentaerythritol tetraoleate esters synthesized from high oleic palm oil methyl ester (POME) have potential as biolubricant base stock. In the present study, the chemical transesterification of POME and pentaerythritol (PE) using sodium methoxide as a catalyst was conducted under vacuum. The effect of operating variables such as reaction temperature, catalyst concentration, the molar ratio of POME to PE, vacuum pressure, and stirring rate on the yield of PE tetraoleate was examined. The ideal conditions for the reaction were at a temperature of 160 °C, 1.25% (w/w) catalyst concentration, the molar ratio of POME to PE at 4.5:1, vacuum pressure at 10 mbar, and stirring speed at 900 rpm. PE tetraoleate with a yield of 36% (w/w), was successfully synthesized under this condition within 2 h of reaction time.

Edible gelatin-based nanofibres loaded with oil encapsulating high-oleic palm oil emulsions

Gelatin-based nanofibres (NF) incorporating a high-oleic palm oil (HOPO) nanoemulsion or macroemulsion were electrospun. An I-optimal response surface design was used for studying the effect of gelatin mass fraction, tip-collector distance and emulsion type (factors) on fibre diameter (Df). The NF had a Df ranging from 136.9 to 240.8 nm and no beads; synergic effects between factors were observed as significant over Df. Furthermore, topography, roughness, oil distribution, peroxide value (PV), antioxidant activity (AOX), thermal stability and crystallinity of two optimised NF were analysed; smooth and slightly rugose NF were observed by atomic force microscopy (AFM) and heterogeneously distributed oil by confocal laser scanning microscopy (CLSM). Microfluidisation and electrospinning had low PV, high encapsulation efficiency (>94 %) and high AA values, i.e., efficient encapsulation processes. NF thermal stability was affected by emulsion type; a more amorphous structure tended to give higher droplet size inside fibres. Despite Df was not affected by emulsion droplet size, NF’s physico-chemical properties showed changes.

In-vitro digestion of whey protein- and soy lecithin-stabilized High Oleic Palm Oil emulsions

Sweet whey- and soy lecithin-stabilized emulsions have been studied as potential delivery systems of High Oleic Palm Oil bioactive compounds. However, the gastrointestinal behavior of these systems has not been investigated. In this work, two High Oleic Palm Oil emulsions were submitted to in vitro digestion using a standardized static method. Stability of the emulsions was followed in each digestive phase and the final extent and kinetics release as well as the bioaccessibility of free fatty acids were measured and compared against non-encapsulated control. No changes were found in the droplet size of the emulsion after oral digestion, however, during gastric digestion, destabilization was observed due to the pH and the ionic strength of the medium. During the intestinal phase, nanoemulsions showed the highest rate constant followed and the least free fatty acids release final extent (78.48 ± 3.08 wt%) in comparison with macroemulsions (86.06 ± 2.04 wt%) and control (107.77 ± 1.45 wt%). Saturated fatty acids showed lower bioaccessibility in both emulsions than for control, meanwhile it increased for unsaturated ones. The results obtained allow addressing future research in formulation and design of delivery systems to improve the High Oleic Palm Oil digestibility and bioactive compounds bioaccessibility.