Mixtures of palm kernel oil with cocoa butter and milk fat in compound coatings

Thermal behavior of binary mixtures of palm kernel oil (PKO), cocoa butter (CB), and anhydrous milk fat was used to study mixed-lipid crystallization. This study was related to the physical properties of compound coatings made with these fats. Phase behavior was studied by evaluating changes in melting behavior with composition and time, by creating isosolid diagrams, and by monitoring polymorphic behavior. For binary mixtures, multiple melting peaks and eutectic formation were observed for 30–50% addition levels of CB to PKO, but not for addition of milk fat to PKO. For compound coatings and binary mixtures, made with the same fat composition, hardness of compound coatings increased as solid fat content (SFC) at 25°C of binary mixtures increased. Also, as SFC at 25°C of the binary mixtures increased, induction time for bloom formation and time to fully bloom for compound coatings decreased. Observation of eutectic behavior for binary mixtures indicated softness in a compound coating with the same fat composition, but the converse was not necessarily true.     

Blending of hydrogenated low-erucic acid rapeseed oil,low-erucic acid rapeseed oil,and hydrogenated palm oil or palm oil in the preparation of shortenings

Two ternary systems of fats were studied. In the first system, low-erucic acid rapeseed oil (LERO), hydrogenated lowerucic acid rapeseed oil (HLERO), and palm oil (PO) were blended. In the second system, hydrogenated palm oil (HPO) was used instead of PO and was blended with LERO and HLERO. The blends were then studied for their physical properties such as solid fat content (SFC), melting curves by DSC, and polymorphism (X-ray). HPO showed the highest melting enthalpy after 48 h at 15°C (141±1 J/g), followed by HLERO (131±2 J/g), PO (110±2 J/g), and LERO (65±4 J/g). Binary phase behavior diagrams were constructed from the DSC and X-ray results. Iso-line diagrams of partial-melting enthalpies were constructed from the DSC results, and binary and ternary isosolid diagrams were constructed from the NMR results. The isosolid diagrams demonstrated formation of a eutectic along the binary blend of PO/HLERO. However, no eutectic effect was observed along the binary lines of HPO/HLERO, PO/LERO, HPO/LERO, or HLERO/LERO. The same results were found with the iso-line diagrams of partial-melting enthalpies. As expected, addition of PO or HPO increased polymorphic stability in the β′ form of the HLERO/LERO mixture.     

Melting and Solidification Properties of Palm Kernel Oil,Tallow, and Palm Olein Blends in the Preparation of Shortening

Ternary systems composed of palm kernel oil (PKO), tallow, and palm olein (POo) were studied in terms of their physical properties such as solid fat content (SFC), melting characteristics by DSC and polymorphism by X-ray diffraction. Ternary phase behavior was analyzed with isosolid diagrams. The results showed that as the POo content of the blends was increased the SFC value decreased, while the increase of tallow content increased the SFC value. Eutectic effects within the ternary system were confirmed from the deviation of the measured SFC from the calculated SFC for corresponding thermodynamically ideal blends. The deviation reached a maximum when the amounts of PKO and POo are both about 45%. X-ray diffraction results showed that addition of PKO into the blends promoted stabilization in the β′ crystalline form.     

Application of palm olein in the production of zero‐trans Iranian vanaspati through enzymatic interesterification

The utilization of palm olein in the production of zero‐trans Iranian vanaspati through enzymatic interesterification was studied. Vanaspati fat was made from ternary blends of palm olein (POL), low‐erucic acid rapeseed oil (RSO) and sunflower oil (SFO) through direct interesterification of the blends or by blending interesterified POL with RSO and SFO. The slip melting point (SMP), the solid fat content (SFC) at 10–40 °C, the carbon number (CN) triacylglycerol (TAG) composition, the induction period (IP) of oxidation at 120 °C (IP₁₂₀) and the IP of crystallization at 20 °C of the final products and non‐interesterified blends were evaluated. Results indicated that all the final products had higher SMP, SFC, IP of crystallization and CN 48 TAG (trisaturated TAG), and lower IP₁₂₀, than their non‐interesterified blends. However, SMP, SFC, IP₁₂₀, IP of crystallization and CN 48 TAG were higher for fats prepared by blending interesterified POL with RSO and SFO. A comparison between the SFC at 20–30 °C of the final products and those of a commercial low‐trans Iranian vanaspati showed that the least saturated fatty acid content necessary to achieve a zero‐trans fat suitable for use as Iranian vanaspati was 37.2% for directly interesterified blends and 28.8% for fats prepared by blending interesterified POL with liquid oils.     

Crystallization Behavior and Kinetics of Chocolate-Lauric Fat Blends and Model Systems

Binary mixtures of cocoa butter and lauric fats have widespread use in chocolates and confections, yet incompatibilities between these fats can present formulation and processing constraints. This study examined the phase behavior and crystallization kinetics of cocoa butter-lauric fat model systems and chocolate-lauric fat blends. Solid fat content (SFC) profiles and isosolid diagrams confirmed eutectic and diluent interactions, indicating a softening of cocoa butter by lauric fat addition. Crystallization kinetics of model systems adhered to an exponential growth model. High lauric fat levels delayed crystal growth and reduced equilibrium SFC of cocoa butter. Coconut and palm kernel oils altered the solidification mechanisms of cocoa butter to a greater extent than fractionated palm kernel oil. Chocolate systems displayed multi-step crystal growth that contrasted with the exponential growth observed in the model systems. At high lauric fat levels (30%), crystallization onset was significantly lengthened. Blends with high lauric fat contents showed low \(G_{{\text {max}} }^{\prime }\) and did not achieve final equilibrium after 60 min of cooling, indicating incomplete crystallization.     

Comparative Study of Table Margarine Prepared from Moringa oleifera Seed Oil‐Palm Stearin Blend and Commercial Margarines: Composition,Thermal, and Textural Properties

This study aims to produce an oleic acid‐rich table margarine from Moringa oleifera seed oil (MoO)‐palm stearin (PS) blend (70:30, w/w) and compare its composition, thermal behavior, and textural properties during storage with those of commercial margarines (CM1 and CM2). The major fatty acid in MoO/PS blend, CM1 and CM2 is oleic acid (67.85%, 38.54%, and 35.35%, respectively). Hence, many of their triacylglycerols are derived from the acid. MoO/PS blend has a higher complete melting temperature (43.50 °C) compared to CM1 (35.50 °C) and CM2 (35.53 °C). The solid fat content (SFC) of MoO/PS blend at 10 °C (28.7%) is lower than CM1 (32%) and CM2 (68.4%). However, the MoO/PS blend has a higher SFC (6.47%) at 35 °C compared to CMs. At 20 °C, the viscosity of experimental blend margarine (EBM) decreases but CM1 and CM2 increase at the end of the storage study. After 8 weeks of storage, all margarines are harder and CM2 is the hardest. The adhesiveness of EMB and CM2 is similar to the fresh samples while CM1 is more adhesive after storage. In short, it is possible to produce an oleic acid‐enriched margarine from MoO/PS blend that has better textural properties. Practical Applications: Moringa oleifera seed oil is one of the superior oils that contains high levels of oleic acid. However, its high iodine value and low melting point limit its application in the production of margarine. This study shows that direct blending of M. oleifera seed oil with palm stearin could produce margarine with high oleic acid contents and better textural properties in terms of viscosity, hardness, and adhesiveness. The informative data provide supporting evidence for blending of M. oleifera seed oil with palm stearin to produce margarine that could overcome the issues that hinder the M. oleifera seed oil from being produced into margarine.     

Interfacial Crystallization of Diacylglycerols Rich in Medium‐ and Long‐Chain Fatty Acids in Water‐in‐Oil Emulsions

The effects of diacylglycerols rich in medium‐ and long‐chain fatty acids (MLCD) on the crystallization of hydrogenated palm oil (HPO) and formation of 10% water‐in‐oil (W/O) emulsion are studied, and compared with the common surfactants monostearoylglycerol (MSG) and polyglycerol polyricinoleate (PGPR). Polarized light microscopy reveals that emulsions made with MLCD form crystals around dispersed water droplets and promotes HPO crystallization at the oil‐water interface. Similar behavior is also observed in MSG‐stabilized emulsions, but is absent from emulsions made with PGPR. The large deformation yield value of the test W/O emulsion is increased four‐fold versus those stabilized via PGPR due to interfacial crystallization of HPO. However, there are no large differences in droplet size, solid fat content (SFC), thermal behavior or polymorphism to account for these substantial changes, implying that the spatial distribution of the HPO crystals within the crystal network is the driving factor responsible for the observed textural differences. MLCD‐covered water droplets act as active fillers and interact with surrounding fat crystals to enhance the rigidity of emulsion. This study provides new insights regarding the use of MLCD in W/O emulsions as template for interfacial crystallization and the possibility of tailoring their large deformation behavior. Practical Applications: MLCD is applied in preparing W/O emulsion. It is found that MLCD forms unique interfacial Pickering crystals around water droplets, which promote the surface‐inactive HPO nucleation at the oil‐water interface. Thus MLCD‐covered water droplets act as active fillers and interact with surrounding fat crystals, which can greatly enhance the rigidity of emulsion. This observation would provide a theoretical reference and practical basis for the application of the MLCD with appreciable nutritional properties in lipid‐rich products such as whipped cream, shortenings margarine, butter and ice cream, so as to substitute hydrogenated oil. MLCD‐stabilized emulsions can also be explored for the development of novel confectionery products, lipsticks, or controlled release matrices.     

Performance of palm‐based fat blends with a low saturated fat content in puff pastry

Four fat blends based on palm fractions in combination with high oleic sunflower oil (HOSF) with a relatively low saturated fatty acid content (29.2 ± 0.85%, i.e. less than 50% of that of butter) were prepared. The saturated fat was located in different TAG structures in each blend. Principal saturated TAG were derived from palm stearin (POs, containing tripalmitoyl glycerol—PPP), palm mid‐fraction (PMF, containing 1,3‐dipalmitoyl‐2‐oleoyl glycerol—POP) and interesterified PMF (inPMF, containing PPP, POP and rac‐1,2‐dipalmitoyl‐3‐oleoyl glycerol—PPO). Thus, in blend 1, composed of POs and HOSF, the saturates resided principally in PPP. In blend 2, composed of POs, PMF and HOSF, the principal saturate‐containing TAG were PPP and POP. Blend 3, composed of inPMF and HOSF, was similar to blend 2 except that the disaturated TAG comprised a 2:1 mixture of PPO:POP. Finally, blend 4, a mixture of PMF and HOSF, had saturates present mainly as POP. The physical properties and the functionality of blends, as shortenings for puff pastry laminated in a warm bakery environment (20–24°C), were compared with each other, and with butter. Puff pastry prepared with blend 1 (POs:HOSF 29:71) and blend 4 (PMF:HOSF 41:59), was very hard; blend 2 (POs:PMF:HOSF 13:19:68) was most similar to butter in the compressibility of the baked product and it performed well in an independent baking trial; blend 3 (inPMF:HOSF 40:60) gave a product that required a higher force for compression than butter.     

Physical properties of lipase‐catalyzed interesterification of palm stearin with canola oil blends

Interesterified blends of hard palm stearin (IV of 11) and canola oil (hPS/CO) in ratios of 20 : 80, 30 : 70, 40 : 60, 50 : 50, 60 : 40 and 70 : 30 were prepared using immobilized Thermomyces lanuginosus lipase (Lipozyme TL IM). Comparison of physical properties was carried out between non‐interesterified and enzymatically interesterified products by monitoring their slip melting point (SMP), solid fat content (SFC), melting thermogram and polymorphism behavior. The Lipozyme TL IM‐catalyzed interesterification significantly modified the physical properties of the hPS:CO blends. The results showed that all the interesterified blends had lower SMP and SFC than their unreacted blends. The SMP result showed that the interesterified blends of hPS/CO 40 : 60, 50 : 50 and 60 : 40 could be useful for stick margarine and shortening applications, respectively. From the SFC analysis, the interesterified blends of hPS/CO 40 : 60 have SFC curves similar to vanaspati. The interesterified blends of hPS/CO 50 : 50 and 60 : 40 have SFC curves similar to margarines, puff pastry margarine and shortening. Interesterification had replaced the higher‐ and lower‐melting triacylglycerols by the middle‐melting triacylglycerols, yielding mixtures of lower SMP and SFC, compared to the original palm stearin. X‐ray diffraction analysis indicated the appearance of β' crystals in all the interesterified hPS/CO blends from predominantly β‐type oils.     

CLA‐Rich Soy Oil Shortening Production and Characterization

Conjugated linoleic acid‐rich soy oil (CLARSO) has been shown to have numerous health benefits, including anti‐obesity and anti‐carcinogenic properties. This oil was previously used to produce CLA‐rich margarine that showed physical characteristics similar to commercially available margarine. The objective of this study was to produce CLA‐rich shortening and analyze its physical properties relative to commercially available shortenings and soy oil control shortenings. The shortenings were prepared and their rheology, thermal behavior, and solid fat content (SFC) were determined and compared to the commercial samples. The CLA‐rich shortening samples showed similar rheological properties to the commercial samples and showed a better consistency (more solid‐like behavior) compared to the soy oil control samples. In addition, the CLA‐rich shortenings also have a higher SFC (% SFC) as well as higher latent heat of crystallization and melting than the soy oil controls indicating a comparatively higher crystalline fraction. Thus, CLARSO produced firmer shortenings than did conventional soy oil by interacting with the crystallizing stearin fraction and consequently increasing the crystalline mass fraction without significantly altering the microstructure kinetics of solid fat crystallization.     

Solid contents of palm‐based biofuel mixtures with respect to storage and handling

The solid content (SC) of biofuel mixtures obtained from mixing crude palm oil (CPO) with medium fuel oil (MFO), and refined palm oil (RPO) with petroleum diesel (PD), was investigated. The SC of these mixtures will impact on their applications, storage and handling. The concentrations of CPO and RPO in the investigated mixtures ranged from 5 to 90% for the CPO‐MFO system and from 0 to 10% for the RPO‐PD system. For CPO/MFO mixtures, their SC exhibited eutectic behavior over the temperature range measured (5–20 °C). Eutectic minima were observed in the 80–90% CPO concentration range for all temperatures. These eutectic minima are due to dilution effects and the formation of van der Waals hydrogen bonds between the asphaltenes in MFO and the triacylglycerols. RPO/PD mixtures did not show any eutectic behavior. The SC for the RPO/PD mixtures were observed to be below 4% at 5 °C after 24 h of tempering and 0% at 15 °C over the same tempering period. When semi‐solid, ambient PO is used as a biofuel, heating is required to liquify it for ease of handling. When mixed with petroleum‐based fuels in the correct proportion, present handling and storage equipment and facilities are adequate for handling these mixtures.     

Effect of Palm Oil Enzymatic Interesterification on Physicochemical and Structural Properties of Mixed Fat Blends

The physicochemical properties of binary and ternary fat systems made of commercial samples of palm oil (PO) blended with anhydrous milk fat (AMF) and/or rapeseed oil (RO) were studied. Physical properties such as solid fat content by pulsed‐Nuclear Magnetic Resonance (p‐NMR), melting profile by differential scanning calorimetry (DSC), and polymorphism of the blends were investigated. Palm oil was then batch enzymatically interesterified for 27 h, using Lipozyme^® TL IM as biocatalyst, and further blended with AMF and/or RO in the same way. The objective of the present work was to evaluate the effect of batch enzymatic interesterification (B‐EIE) of palm oil on physical characteristics of the investigated fat blends. For that purpose, iso‐solid diagrams have been constructed from p‐NMR data. It was shown that B‐EIE of palm oil modifies its melting behaviour, but also its polymorphic stability and miscibility with other fats. Under dynamic conditions, after B‐EIE, the non‐ideal behaviour (eutectic) detected at low temperatures in the ternary PO/AMF/RO system disappears in the corresponding EIE‐PO/AMF/RO. After static crystallization followed by a tempering, the hardness of palm oil is increased after B‐EIE, as well as the hardnesses of the blends containing this fat compared to the native one. Polymorphism stability of the binary and ternary fat systems is also modified after B‐EIE compared to the corresponding native systems.     

Modelling lipase‐catalysed transesterification of fats containing n‐3 fatty acids monitored by their solid fat content

Transesterification of fat blends rich in n‐3 polyunsaturated fatty acids (n‐3 PUFA), catalysed by a commercial immobilised thermostable lipase from Thermomyces lanuginosa, was carried out batch‐wise. Experiments were performed, following central composite rotatable designs (CCRDs) as a function of reaction time, temperature and media formulation. Mixtures of palm stearin, palm kernel oil and a commercial concentrate of triacylglycerols rich in n‐3 PUFA (“EPAX 2050TG” in CCRD‐1 and “EPAX 4510TG” in CCRD‐2) were used. The time‐course of transesterification was indirectly followed by the solid fat content (SFC) values of the blend at 10 °C, 20 °C, 30 °C and 35 °C. A decrease in all SFC values of the blends at 10 °C, 20 °C, 30 °C and 35°C was observed upon transesterification. The SFC_{10 °C} and SFC_{20 °C} of transesterified blends varied between 18 and 48 and SFC_{35 °C} between 6 and 24. These values fulfil the technological requirements for the production of margarines. Under our conditions, lipid oxidation may be neglected. However, the accumulation up to 8.3% free fatty acids in reaction media is a problem to overcome. The development of response surface models, describing both the final SFC value and the SFC decrease, will allow predicting results for novel proportions of fats and oils and/or a novel combination time‐temperature.     

Comparison of Oleo‐ vs Petro‐Sourcing of Fatty Alcohols via Cradle‐to‐Gate Life Cycle Assessment

Alcohol ethoxylates surfactants are produced via ethoxylation of fatty alcohol (FA) with ethylene oxide. The source of FA could be either palm kernel oil (PKO) or petrochemicals. The study aimed to compare the potential environmental impacts for PKO‐derived FA (PKO‐FA) and petrochemicals‐derived FA (petro‐FA). Cradle‐to‐gate life cycle assessment has been performed for this purpose because it enables understanding of the impacts across the life cycle and impact categories. The results show that petro‐FA has overall lower average greenhouse gas (GHG) emissions (～2.97 kg CO₂e) compared to PKO‐FA (～5.27 kg CO₂e). (1) The practices in land use change for palm plantations, (2) end‐of‐life treatment for palm oil mill wastewater effluent and (3) end‐of‐life treatment for empty fruit bunches are the three determining factors for the environmental impacts of PKO‐FA. For petro‐FA, n‐olefin production, ethylene production and thermal energy production are the main factors. We found the judicious decisions on land use change, effluent treatment and solid waste treatment are key to making PKO‐FA environmentally sustainable. The sensitivity results show the broad distribution for PKO‐FA due to varying practices in palm cultivation. PKO‐FA has higher impacts on average for 12 out of 18 impact categories evaluated. For the base case, when accounted for uncertainty and sensitivity analyses results, the study finds that marine eutrophication, agricultural land occupation, natural land occupation, fossil depletion, particulate matter formation, and water depletion are affected by the sourcing decision. The sourcing of FA involves trade‐offs and depends on the specific practices through the PKO life cycle from an environmental impact perspective.     

Operational stability of Thermomyces lanuginosa lipase during interesterification of fat in continuous packed‐bed reactors

The operational stability of a commercial immobilized lipase from Thermomyces lanuginosa (“Lipozyme TL IM”) during the interesterification of two fat blends, in solvent‐free media, in a continuous packed‐bed reactor, was investigated. Blend A was a mixture of palm stearin (POS), palm kernel oil (PK) and sunflower oil (55 : 25 : 20, wt‐%) and blend B was formed by POS, PK and a concentrate of triacylglycerols rich in n‐3 polyunsaturated fatty acids (PUFA) (55 : 35 : 10, wt‐%). The bioreactor operated continuously at 70 °C, for 580 h (blend A) and 390 h (blend B), at a residence time of 15 min. Biocatalyst activity was evaluated in terms of the decrease of the solid fat content at 35 °C of the blends, which is a key parameter in margarine manufacture. The inactivation profile of the biocatalyst could be well described by the first‐order deactivation model: Half‐lives of 135 h and 77 h were estimated when fat blends A and B, respectively, were used. Higher levels of PUFA in blend B, which are rather prone to oxidation, may explain the lower lipase stability when this mixture was used. The free fatty acid content of the interesterified blends decreased to about 1% during the first day of operation, remaining constant thereafter.     

Effects of Sucrose Esters on Isothermal Crystallization of Palm Oil‐based Blend

The effects of sucrose esters (SEs) with different acyl chain lengths, namely, lauryl (L‐195), palmitoyl (P‐170), stearoyl (S‐170), oleoyl (O‐170), and erucyl (ER‐190), on isothermal crystallization of a palm oil‐based blend (PO–PS) were studied. From this study, it was found that both α‐ and β′‐crystals coexisted following crystallization of PO–PS from melt to room temperature. Addition of SEs P‐170 and S‐170, which had saturated acyl chains similar to PO–PS, resulted in an accelerating crystallization rate, promoting the appearance of α‐crystals and transition to β′‐crystals and increasing viscosity of PO–PS blend. SE O‐170, which is liquid at room temperature, had little effect on blend crystallization. SEs L‐195 and ER‐190, with an acyl chain dissimilar to PO–PS, inhibited triacylglycerol bonding or further integration to the surface of crystals and reduced the crystallization rate and viscosity of the PO–PS blend. The PO–PS blend with SE L‐195 and ER‐190 contained large crystals and resulted in slower formation of α‐crystals and transformation to β′‐crystals. Results from this study indicate that crystallization of PO–PS was greatly influenced by acyl–acyl interactions between acyl chains of SEs and triacylglycerols.     

Crystallization behavior of milk fat,palm oil,palm kernel oil,and cocoa butter with and without the addition of cannabidiol

The objective of this study was to evaluate the effect of cannabidiol (CBD) on the crystallization behavior and physical properties of various fats. Anhydrous milk fat (AMF), palm oil (PO), palm kernel oil (PKO), and cocoa butter (CB) were chosen for this study, for their unique crystallization behaviors. CBD was added at 1 and 2.5% wt/wt to these fats, and the crystallization behavior was evaluated at 26°C for AMF and PO and at 22°C for PKO and CB. Control samples with no CBD were prepared and evaluated as well. Results show that CBD delayed the crystallization of all fats with the least effect observed for the PO. Slight increases in crystal size were observed with the addition of CBD for all samples. CBD did not affect the melting profile of AMF or CB, but it increased the peak temperature of PO and decreased the enthalpy of PKO. Similarly, hardness was only affected by CBD in PO samples, with harder materials obtained for samples containing 2.5% CBD. The same trend was observed for elasticity. In addition, the elasticity of AMF increased with the addition of CBD but not its hardness. Overall, this study indicates that the effect of CBD on fat crystallization is highly dependent on the type of fat used. Producers of fat-based products that are willing to include CBD in their formulations must carefully control processing conditions to ensure product quality.     

The influence of chemical interesterification on physicochemical properties of complex fat systems 1. Melting and crystallization

The effects of blending palm oil (PO) with soybean oil (SBO) and lard with canola oil, and subsequent chemical interesterification (CIE), on their melting and crystallization behavior were investigated. Lard underwent larger CIE-induced changes in triacylglycerol (TAG) composition than palm oil. Within 30 min to 1 h of CIE, changes in TAG profile appeared complete for both lard and PO. PO had a solid fat content (SFC) of ∼68% at 0°C, which diminished by ∼30% between 10 and 20°C. Dilution with SBO gradually lowered the initial SFC. CIE linearized the melting profile of all palm oil-soybean oil (POSBO) blends between 5 and 40°C. Lard SFC followed an entirely different trend. The melting behavior of lard and lard-canola oil (LCO) blends in the 0–40°C range was linear. CIE led to more abrupt melting for all LCO blends. Both systems displayed monotectic behavior. CIE increased the DP of POSBO blends with ≥80% PO in the blend and lowered that of blends with ≤70% PO. All CIE LCO blends had a slightly lower DP vis-à-vis their noninteresterified counterparts.     

Physical properties of shortenings with low‐trans fatty acids as affected by emulsifiers and storage conditions

The quality of shortenings, such as solid fat content (SFC) and texture, strongly depends on temperature fluctuations during storage and handling. The quality of a shortening might be affected not only by temperature fluctuations but also by its chemical composition and the presence of emulsifiers. The objective of this work was to investigate the effect of emulsifier addition and storage conditions on the texture, thermal behavior and SFC of low‐trans shortenings formulated with palm oil, palm kernel oil, and vegetable oils such as sunflower and soybean oils. Several conclusions can be drawn from this study: (a) The crystallization behavior of fat blends strongly depends on the type of emulsifier used and the chemical composition of the sample; (b) the addition of emulsifiers affects not only the type of crystals formed (fractionation) but also the amount of crystals obtained (enthalpy, SFC), inducing or delaying the crystallization process; (c) emulsifiers affect the texture of the crystalline structure formed by making it softer; (d) the storage conditions affect both the texture and the SFC of the materials. This study shows that samples that are highly super‐cooled during storage become harder while samples that are less super‐cooled become softer with storage conditions.     

Physical properties of Pseudomonas and Rhizomucor miehei lipase-catalyzed transesterified blends of palm stearin:palm kernel olein

The physical properties of Pseudomonas and Rhizomucor miehei lipase-catalyzed transesterified blends of palm stearin:palm kernel olein (PS:PKO), ranging from 40% palm stearin to 80% palm stearin in 10% increments, were analyzed for their slip melting points (SMP), solid fat content (SFC), melting thermograms, and polymorphic forms. The Pseudomonas lipase caused a greater decrease in SMP (15°C) in the PS:PKO (40:60) blend than the R. miehei lipase (10.5°C). Generally, all transesterified blends had lower SMP than their unreacted blends. Pseudomonas lipase-catalyzed blends at 40:60 and 50:50 ratio also showed complete melting at 37°C and 40°C, respectively, whereas for the R. miehei lipase-catalyzed 40:60 blend, a residual SFC of 3.9% was observed at 40°C. Randomization of fatty acids by Pseudomonas lipase also led to a greater decrease in SFC than the rearrangement of fatty acids by R. miehei lipase. Differential scanning calorimetry results confirmed this observation. Pseudomonas lipase also successfully changed the polymorphic forms of the unreacted blends from a predominantly β form to that of an exclusively β′ form. Both β and β′ forms existed in the R. miehei lipase-catalyzed reaction blends, with β′ being the dominant form.