Slip Melting Point Research Articles

Effect of Fatty Acid Chain Length on the Crystallization Behavior of Trans-free Margarine Basestocks during Storage.

In order to obtain margarine free of trans-fatty acids, four interesterified basestocks were prepared by chemical interesterification (CIE) of oil blends. Different ratios of palm stearin, palm olein and soybean oil were mixed without and with 1) fully hydrogenated Acer truncatum oil (FHATO), 2) fully hydrogenated rapeseed oil or 3) palm kernel oil containing a similar amount of saturated, monounsaturated and polyunsaturated fatty acids, but different saturated fatty acid length for CIE. Compared to the physical blends, the CIE samples demonstrated lower slip melting points and decreased solid fat contents, especially at high temperatures, indicating that the CIE samples might have improved mouthfeel. In all CIE samples, the β crystal form disappeared and only the β' crystal form was observed, except for sample 2, which contained a mixed β and β' forms. Furthermore, in all CIE samples, except sample 1, the β' crystal forms began transforming to β form after only two cycles of higher temperature treatments indicating that the CIE sample with FHATO had the most resistance to temperature fluctuation during storage which may be attributed to its longer saturated chains. In conclusion, the CIE basestocks containing longer saturated fatty acids could be more suitable for margarine use.

Enzymatic interesterification of sunflower oil and hydrogenated soybean oil with the immobilized bacterial recombinant lipase from Geobacillus stearothermophilus G3

In this study we discuss the properties of biocatalyst based on Geobacillus stearothermophilus G3 lipase immobilized on silica gel. Interesterification of sunflower oil and hydrogenated soybean oil (HSO) in a batch reaction was completed within 2 h, 10% biocatalyst (wt %), 70°С, and HSO: sunflower oil molar ratio of 1: 3. The physical and chemical parameters of reaction products were studied by HPLC-MS to access the composition of triacylglycerides and by slip melting point method. Biocatalyst has shown high operational stability. The estimated time of its operation in the oil mixture was 243 h that makes this catalyst promising for application in manufacturing of modified fats, including fats with high melting temperatures.

Production of High‐Melting Symmetrical Monounsaturated Triacylglycerol‐Rich Fats from Mango Kernel Fat by Acetone Fractionation

Abstract1,3‐Distearoyl‐2‐oleoyl‐glycerol, 1‐palmitoyl‐2‐oleoyl‐3‐stearoyl‐glycerol and 1‐stearoyl‐2‐oleoyl‐3‐arachidoyl‐glycerol are typical high‐melting symmetrical monounsaturated triacylglycerols (Hm‐SMT) found in cocoa butter improver (CBI). These triacylglycerols help to increase the hardness of chocolate products in tropical climates. In the present study, natural CBI products were produced from mango (Mangifera indica, Linn) kernel fat (MKF) by selective three‐stage fractionation using acetone. The second stearin (fraction I) from the first precipitate of MKF by fractionation for 180 min at 15 °C contained 86.9% of Hm‐SMT, and the third stearin (fraction II) obtained from fraction I by further fractionation for 180 min at 18 °C was enriched with 94.4% Hm‐SMT. High percentages of such triacylglycerols in these products contributed to higher slip melting points (36.5–37.7 °C) than commercial cocoa butter and cocoa butter equivalent (26.7 and 27.9 °C). Also, their differential scanning calorimetry properties and solid fat content values were superior to those in traditional confectionery fats, indicating that the tailored stearins could be used as ideal CBI. In particular, the hard fat blends consisting of 55–70% cocoa butter (CB) and 30–45% fraction II were considered as the preferred heat‐resistant chocolate ingredients. In addition, the mixture of the oleins (fraction III) was rich in diunsaturated and triunsaturated triacylglycerols and showed similar thermal properties to super palm oil, thus making it more suitable as special fat ingredients and modified fat sources.

Description of melting curves of enzymatically interesterified blends of fully hydrogenated palm olein and soybean oil by sigmoidal functions

Abstract Margarines and shortenings are generally characterized by their solid fat content (SFC) and melting point. Interesterification has been widely used for production of trans-free margarines and shortenings. In this study, blends of fully hydrogenated palm olein (FHPO) and soybean oil were interesterified using the Lipozyme TL IM and the potential of three sigmoidal functions (including the Logistic, Sigmoid and Gompertz equations) in description of SFC or slip melting point (SMP) of the enzymatically interesterified blends was evaluated. The SFC as a function of temperature (SFCf(T)) or saturated fatty acids (SFCf(SFA)) curves, and SMP as a function of SFA (SMPf(SFA)) curve had sigmoidal shapes and all the sigmoidal functions were able to describe the SFC and SMP curves. However, the Gompertz model described them in the best way. Mean absolute error (MAE) of SFCf(T) and SFCf(SFA) models (described by the Gompertz function) were less than 1.75% and 1.22% respectively. The Gompertz function could describe the SMPf(SFA) curves with high R2 (0.99) and low MAE (0.65 °C). In addition, the obtained model could describe the SMP of interesterified palm olein-based fat blends with MAE lower than 3.1 °C. However, poor results obtained when the model was used for prediction of SMP of interesterified fats made from fully hydrogenated soybean oil (MAE=5.2–9.8 °C). Models described in this study can be used as screening tools in formulation of interesterified margarine and shortening fats.

EFFECT OF CHEMICAL AND ENZYMATIC INTERESTERIFICATION ON THE PHYSICOCHEMICAL PROPERTIES OF PALM OIL AND. PALM KERNEL OIL BLENDS

Palm oil (PO) and palm kernel oil (PKO) have different chemical composition and physical properties. Both oils have limited application in their natural form. To widen their commercial values, PO and PKO were modified by blending and subsequently followed by interesterification (IE). Interesterification is the rearrangement of fatty acids within and among different triacylglycerols, using enzyme or chemical as the catalysts. Palm oil with iodine value (IV) of 52.6 and PKO (IV = 17.5) were mixed in different ratios from 25:75 to 75:25 (%wt/wt) at 25% increment. The blends were subjected to chemical and enzymatic interesterification using sodium methoxide and Lipozyme TL IM as catalysts, respectively. The effects of chemical and enzymatic interesterification on the triacylglycerols (TAG) composition, thermal properties, solid fat content (SFC) and slip melting point (SMP) were investigated. Chemical interesterification (CIE) caused significant changes in the TAG composition of the oil blend compared to enzymatic interesterification (EIE). This changes led to a significantly higher (p<0.05) SMP for the chemically-interesterified than the enzymatically-interesterified blends. The differential scanning calorimetry (DSC) melting thermograms confirmed that harder product with higher final complete melting temperature was obtained from the chemically-interesterified blends. Similar SFC profiles for all oil blends were observed with steep SFC slopes for blend with high proportion of PKO. Chemical interesterification reduced the eutectic interactions that occurred at 5 to 25°C in the non-interesterified and enzymatically-interesterified blends. Thus, CIE caused significant changes in physicochemical properties of the PO and PKO blends compared to EIE. Results from this study could improve the existing PO and PKO properties and widen their usage in food and non-food applications.

Origin of reduced anisotropic deformation in hexagonal close packed Ti-Al alloy

The origin of low ductility in the hexagonal close-packed (hcp) metal system like Ti is high anisotropic critical resolved shear stress (CRSS) of different slip systems. To reduce the anisotropic deformation is a key for improving the mechanical performance. In the present study, Al alloying shows it can effectively weaken the anisotropic deformation of the hcp system. The relationship between Al alloying and anisotropic deformation was studied by X-ray diffraction, geometric phase analysis, and ab initio calculations. The atomic-scale mechanism behind the isotropic deformation of the Ti-Al alloy was shown that {10−10} prismatic planes were the preferred substitution planes for the Al atoms. The hardening trend of prismatic slip was faster compared to that of basal slip. A high CRSS rate and low CRSS starting point of prismatic slip contributed to the reduction in anisotropic deformation of the Ti-Al alloy.

Structuring of Chicken Fat by Monoacylglycerols

AbstractIn this study, we investigated the effect of monoacylglycerol (MAG) as a structuring agent on the physicochemical, microstructure and rheological properties of chicken fat. The fatty acid composition, oxidative stability, free fatty acids (FFA), slip melting point (SMP), solid fat content (SFC), kinetics of crystallization, microstructure and rheological properties of the samples were evaluated. The addition of MAG at a 0.5 % level did not affect the fatty acid composition, induction period of oxidation at 110 °C (IPox110), SFC curve or rheological properties of chicken fat (p > 0.05). However, structured samples containing 3.0 and 5.0 % MAG had higher saturated fatty acid (SFA) content, SFC, SMP, FFA content and IPox110 (p < 0.05). The addition of MAG led to a reduction in the IP of oxidation at 60 °C (IPox60) and increased the oxidation rate of fats, as measured by the Schaal oven test. Samples containing 3–5 % MAG had higher SFC content, higher loss, storage and complex moduli, higher complex viscosity, and a lower induction period of crystallization (IPcryst) and tan δ than chicken fat. Investigations by polarized light microscopy confirmed the presence of increased crystal content in samples containing higher MAG levels. These results show that structured chicken fats have the potential for application in the production of soft tub margarine and Iranian vanaspati.

Physicochemical characteristics of phytonutrient retained red palm olein and butter-fat blends and its utilization for formulating chocolate spread.

Phytonutrients retained palm olein (PRPOL) was prepared and blended into butterfat at different ratios. The physicochemical characteristics and the phytonutrient composition of blends, as well as its utilization in the preparation of functional chocolate spread were evaluated. The results showed that the redness, yellowness, slip melting point, free fatty acids, peroxide value, iodine value, unsaponifiable matter, diacylglycerol and monoacylglycerol increased while lightness, saponification value, and triacylglycerol significantly decreased upon incorporation of increased quantities of PRPOL into butterfat. The incorporation affected short chain, medium chain and long chain fatty acids content along with variation in the palmitic, stearic, oleic acids content of the blends as compared to butterfat alone. Improvement in carotenoids (6-27 fold), phytotosterols (3-15 fold), tocopherols and tocotrienols (4-17 fold), and squalene (1-6 fold) in blends was observed upon incorporation of PRPOL. Cholesterol level in the blends was reduced (10-50%) as compared to the butterfat. The blends showed an intermediate solid fat content of PRPOL and butterfat. Moreover, radical scavenging activity of the blends increased with increase in PRPOL quantity. Prepared chocolate spreads showed similar fat, moisture, colour components (L*, a* and b*) and better emulsion stability. The hardness of the spreads was increased upon increasing quantity of PRPOL. The sensory evaluation showed that chocolate prepared by replacing butterfat with 20% PRPOL had acceptable sensory attributes.

EFFECTS OF CHEMICAL INTERESTERIFICATION ON THE PHYSICOCHEMICAL PROPERTIES OF PALM STEARIN AND RICE BRAN OIL BLENDS

Palm stearin (PS) and rice bran oil (RBO) were blended in the mass ratio of 100:0, 70:30, 50:50, 30:70 and 0:100. The oil blends were subjected to chemical interesterification (CIE) catalyzed by sodium methoxide (0.2% w/w). The following analysis were carried out before and after CIE: triacylglycerol (TAG) composition, slip melting point (SMP), solid fat content (SFC), microstructure, polymorphism and hardness index (HI). After chemical interesterification, there were decrease and increase in the amount of several TAG. Changes in TAG composition caused changes in the physical properties of the blends. Both SMP and SFC of all blends decreased significantly (p<0.05) after interesterification except for RBO. Chemical interesterification also reduced the eutectic interaction at 5°C. However, for hardness index, only blends with 50% and 100% PS decreased significantly (p<0.05) from 33.197 to 26.097 and 5.397 to 3.720, respectively. The crystals of the blends became smaller and reduced in number after interesterification. Interesterification promoted the formation of more β' crystals than β in all blends. The 30:70 PSRBO blend was the most suitable for margarine production as it melted close to body temperature.

Characteristics of Mango Kernel Fats Extracted from 11 China‐Specific Varieties and Their Typically Fractionated Fractions

Abstract11 China‐specific mango varieties, i.e., Tainong, Xiangya, Okrong, Keitt, Chiin Hwang, Guifei, Yuexi, Biantao, Guixiang, Zihua and Guire, were selected from South China, and the kernels were separated from pulps and then dried to extract mango kernel fats (MKF). 5.65–11.14 % of the fats could be obtained from dried kernels using hexane extraction, and their iodine values, slip melting points, triacylglycerols, sn‐2 fatty acids and micronutrients were analyzed. MKF were comprised predominantly of triacylglycerols reaching 85.09–92.72, and 78.28–84.37 % of oleic at the sn‐2 position. 29.99–55.44 % of SOS, 11.17–23.34 % of SOO and 13.10–19.79 % of POS occupied the main percentages of triacylglycerols, indicating MKF have diversified application after fractionation. Certain variety characterized as moderate values mentioned above, therefore, was selected and then fractionated by two‐stage processes to produce typical MKF fractions. The stearin (Fraction‐II) fractionated from the first solid fraction (Fraction‐I) with 68.09 % of SOS and 15.43 % of POS was more suitable as cocoa butter improver, while the olein (Fraction‐III) produced from the first liquid fraction was rich in SOO (45.59 %), POO (11.37 %) and OOO (11.14 %), which are considered as ideal cooking oil or frying fat ingredients. In addition, high amounts of micronutrients, including sterol, tocopherol and squalene, were also found in MKF ranged from 3837 to 7085, 81 to 916, and 164 to 941 mg/kg among different varieties, respectively. In particular, squalene levels were higher compared with most of other vegetable oils.

Trans-free margarine fat produced using enzymatic interesterification of rice bran oil and hard palm stearin.

Trans-free interesterified fats were prepared from blends of hard palm stearin (hPS) and rice bran oil (RBO) at 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, and 80:20 weight % using immobilized Mucor miehei lipase at 60°C for 6 h with a mixing speed of 300 rpm. Physical properties and crystallization and melting behaviors of interesterified blends were investigated and compared with commercial margarine fats. Lipase-catalyzed interesterification modified triacylglycerol compositions and physical and thermal properties of hPS:RBO blends. Slip melting point and solid fat contents (SFC) of all blends decreased after interesterification. Small, mostly β' form, needle-shaped crystals, desirable for margarines were observed in interesterified fats. Interesterified blend 40:60 exhibited an SFC profile and crystallization and melting characteristics most similar to commercial margarine fats and also had small needle-like β' crystals. Interesterified blend 40:60 was suitable for use as a transfree margarine fat.

Rheological and Physicochemical Modification of trans‐Free Blends of Palm Stearin and Soybean Oil by Chemical Interesterification

AbstractIn this study, binary blends of palm stearin and soybean oil were interesterified using sodium methoxide. The changes in free fatty acids (FFA), slip melting point (SMP), solid fat content (SFC), plastic range, induction period of oxidation at 120 °C (IP120) and rheological properties of fat blends, before and after interesterification, were investigated. All blends were trans‐free and contained high essential fatty acids content. Interesterification modified the melting properties of fat blends by reducing SMP and SFC. FFA increased and IP120 decreased after interesterification. Strain sweep, frequency sweep and temperature sweep tests were used to evaluate the rheology of fats. Briefly, the 10:90 and 30:70 (palm stearin : soybean oil) interesterified blends displayed increased storage (G′) and loss (G″) moduli, as compared with the initial blends. However, G′ and G″ moduli of interesterified 50:50 blend were lower than those of initial blends. The elastic character of interesterified 10:90, 30:70 and 50:50 blends was predominant up to 28.8, 37.9, and 41.8 °C, respectively. The interesterified blends of palm stearin and soybean oil showed desirable characteristics suited for production of trans‐free soft tub, stick and Baker's margarine, all‐purpose shortening and Iranian vanaspati.Practical ApplicationsIntake of high amounts of trans fatty acid (TFA) has been correlated with increased risk of heart diseases. In this context, chemical interesterification is an important technological option for production of trans‐free fats with different food applications. The results obtained here provide information about the scientific aspects of the effect of interesterification on rheological and physicochemical properties of palm stearin and soybean oil blends. Practically, this study can find its application in development of formulations for production of trans‐free fat products such as liquid, soft tub, stick and baker's margarine, all‐purpose shortenings and Iranian vanaspati.

Composition of Rice Bran Stearin from Various Refineries Across China

AbstractIn this study, we evaluated the composition of rice bran stearin (RBS) from various refineries across China. Here, we report the physicochemical parameters of RBS. The slip melting point ranged from 20.8 to 35.3 °C. The free fatty acid content (0.05–0.27 %) and peroxide value (0.34–3.70 mequiv oxygen/kg) was quite low, indicating that the RBS was of good quality. The iodine value ranged from 85.8–102.9 g/100 g, indicating a high unsaturated bond content. There was a significant difference in the unsaponifiable matter content (1.20–3.87 %) among RBS samples. The oxidative stability index (OSI) ranged from 0.56 to 5.85 h. The palmitic acid content in RBS refined by molecular distillation was significantly higher than the RBS that was refined physically and chemically. The major triacylglycerol was LLO/OLL, PLL/LPL, OLO, PLP, OOO and POO (L, linoleic acid; O, oleic acid; P, palmitic acid). RBS contained high levels of micronutrients, including total tocopherols (23.3–117.9 mg/100 g), oryzanol (0.1–2.1 %), and total sterols (682.9–1787.3 mg/100 g). Moreover, three different kinds of solid fat curves were distinguished. The results presented here are probably the first report regarding RBS on an industrial scale, meanwhile the potential utilization of RBS is discussed.

Similar physical characteristics but distinguishable sn‐2 palmitic acid content and reduced solid fat content of chemically interesterified palm olein compared with native palm olein by dry fractionation: A lab‐scale study

The presence of solid fat content (SFC) of vegetable fats at human body temperature (37°C) has been linked to altered fat digestibility and metabolism. In this study, the possibility of reducing the SFC in chemically interesterified palm olein (CIEPO) while maintaining physical properties similar to native palm olein was explored by dry fractionation. Crystallization at 37°C for 155 min produced a CIEPO olein fraction with total fatty acid composition (FAC) broadly resembling that of native palm olein while the high proportion of sn‐2 palmitic acid content was maintained at 39.1%. The CIEPO olein fraction has a reduced SFC at 37°C from 8.6 to 4.2%, overall decreased SFC, slip melting point (SMP) at 33°C, a reduced palmitoyl‐palmitoyl‐palmitoyl (PPP) from 6.0 to 3.7 mol% and lower heating peaks in thermal profile compared with the untreated CIEPO. Both CIEPO olein fraction and palm olein have broadly similar total FAC and SMP below 37°C but very distinguishable sn‐2 palmitic acid content. CIEPO olein fraction and native palm olein can be used as effective comparison in human studies because the differences of both fats in PPP content and SFC at 37°C were narrowed.Practical applications: Previous human studies investigating the effects of positional distribution of fatty acids on postprandial lipaemia (abnormally high lipid levels in blood after meal) have yielded contradictory findings. Most of these studies require the use of interesterified fats to distinguish the difference in the sn‐2 fatty acid composition when compared with the untreated form of the fats. The inconsistent findings on lipaemic response from these studies have raised the issue on the importance of using groups of test fats with different positional composition but similar physical characteristics in order to differentiate the effects of positional composition from the physical characteristics of test fats. This study serves as a potential solution to the pairing of test fats with distinguishable sn‐2 profile by creating a CIEPO fraction from dry fractionation with lowered SFC at 37°C while maintaining the physical characteristics of its untreated form that is suitable to be used in future human clinical studies.Human lipid nutrition studies comparing natural dietary fats with interesterified fats require pairs of test fats possessing similar physical properties but distinguishable sn‐2 specific fatty acids content. In the current study, CIEPO was fractionated into olein and stearin at 37°C. Both native palm olein and the CIEPO olein fraction have similar total C16:0 content and SMP below 37°C but distinguishable sn‐2 C16:0 content, whilst the differences of both fats in tripalmitin and SFC at 37°C were narrowed.

TEM study on relationship between stacking faults and non-basal dislocations in Mg

Recent interest in the study of stacking faults and non-basal slip in Mg alloys is partly based on the argument that these phenomena positively influence mechanical behaviour. Inspection of the published literature, however, reveals that there is a lack of fundamental information on the mechanisms that govern the formation of stacking faults, especially I1-type stacking faults (I1 faults). Moreover, controversial and sometimes contradictory mechanisms have been proposed concerning the interactions between stacking faults and dislocations. Therefore, we describe a fundamental transmission electron microscope investigation on Mg 2.5 at. % Y (Mg–2.5Y) processed via hot isostatic pressing (HIP) and extrusion at 623 K. In the as-HIPed Mg–2.5Y, many 〈c〉 and 〈a〉 dislocations, together with some 〈c + a〉 dislocations were documented, but no stacking faults were observed. In contrast, in the as-extruded Mg–2.5Y, a relatively high density of stacking faults and some non-basal dislocations were documented. Specifically, there were three different cases for the configurations of observed stacking faults. Case (I): pure I2 faults; Case (II): mixture of I1 faults and non-basal dislocations having 〈c〉 component, together with basal 〈a〉 dislocations; Case (III): mixture of predominant I2 faults and rare I1 faults, together with jog-like dislocation configuration. By comparing the differences in extended defect configurations, we propose three distinct stacking fault formation mechanisms for each case in the context of slip activity and point defect generation during extrusion. Furthermore, we discuss the role of stacking faults on deformation mechanisms in the context of dynamic interactions between stacking faults and non-basal slip.

Immobilized lipase on core–shell structured Fe3O4–MCM-41 nanocomposites as a magnetically recyclable biocatalyst for interesterification of soybean oil and lard

A core–shell structured Fe3O4–MCM-41 nanocomposite was prepared by means of a surfactant-directed sol–gel process. Candida rugosa lipase was then bound to the magnetic core–shell material by using glutaraldehyde as a cross-linking reagent. The as-prepared Fe3O4–MCM-41 support and the immobilized lipase were characterized in detail using enzyme activity assays, TEM, XRD, FTIR, VSM and nitrogen adsorption–desorption techniques. Results showed that the magnetite nanoparticles were coated with the MCM-41 silica with the formation of core–shell structured materials, and the lipase was successfully immobilized on the core–shell structured support. The catalytic performance of the bound lipase was tested in the interesterification of lard and soybean oil. It was shown that the immobilized lipase had a better catalytic activity towards the interesterification reaction. The slip melting point of the final product was lower than that of the original blend, and the interesterification led to an obvious variation in the microstructure of the product.

English

Traditionally in Igbo land folklore medicine, Virescens (Ojukwu) palm oil of Eleaisguineensis is of value as anti-poison and miracle oil. The objective of the study was to evaluate the physiochemical properties with the identification of the fatty acids of the Virescens oil in comparison to Nigrescens oil of Eleaisguineensis. The result of the physiochemical properties shows that the values for meeting point (slip point) of the oils were found to be the same (33°C) while solidification (titer) point, 22°C, viscosity, 51.20 centistokes and moisture content, 1.6% of Nigrescens (ordinary) palm oil are higher than that of Virescens palm oil with solidification point (titer) point, 15°C; viscosity 29.89 centistokes and moisture content, 0.2%. Both Virescens oil, 83.82 and Nigrescens oil, 53.98 are non-drying oil (low iodine value) and have high saponification values (Virescens, 222.3 and Nigrescens, 223.7). The result of the peroxide value revealed that there are more peroxides in Virescens oil (15 and 18) than in Nigrescens oil (8 and 12.3) for a week and 4 weeks oil respectively. Results on Ester value revealed high ester value (Virescens, 265.78 and Nigrescens, 263.16) with percent Ester purity of 21.11% for Virescens and 21.32% for Nigrescens. Nigrescens have higher acid value (40.67) than Virescens (29.73). The fatty acid analysis result revealed the presence of oleic, stearic acid, tocopherol in both the Virescens and Nigrescens palm oil with RF values of 0.50 (oleic), 0.40 (stearic) and 0.29 (tocopherol) while lecithin was only observed in Virescens palm oil with RF value of 0.34. Some values of Virescens were found to agree with the same value of olive oil and the presence of lecithin suggests why Virescens is anti-poison and medicinal.   Key words: Virescens and Nigrescens palm oil, physiochemical properties, anti-poison, medicinal. &nbsp

The condition for first slip in a common edge contact subject to in-plane and anti-plane loading

A contact is formed from two elastically similar cylinders of the same diameter and having ends cut at the same angle, not necessarily perpendicular to their axes, pressed end to end. The interface experiences Coulomb friction and the assembly is subject to transverse shear and remote torsion. This constitutes a contact with a mutually defined extent. The condition for and location of the point of first slip are found. It is shown that torsion (anti-plane loading) encourages edge slip and transverse (in-plane) shear encourages slip from an interior point. The necessary condition for adhesion at the edge under the most general condition is derived.

Synthesis of Cocoa Butter Equivalent from Formulated Hard Palm Oil Mid-Fraction and Canola Oil Blends

Cocoa butter (CB) is an important major constituent of chocolate and other confectionary products. Several factors such as premium price, uncertainty in supply and variability in quality, have led the search for an alternative such as cocoa butter equivalent (CBE) from available and cheap commercial oils or fats. The aim of this research was to produce CBEs which contain omega-3 and omega-6 by blending hard palm oil mid-fraction (PMF) with canola oil. The reaction was performed by using Lipozyme RM IM as the biocatalyst. It aims to retain omega-3 and omega-6 content in CBE after interesterification. The effect of lipase load (LL), time reaction (TR) and stearic acid (ST) on CBE properties were studied to produce nearly similar CBE properties to CB. The best reaction conditions for maximizing POS (palmitic-oleic-stearic), SOS (stearic-oleic-stearic), and SMP (slip melting point) value while minimizing POP (palmitic-oleic-palmitic) and the levels of diacylglycerol (DAG) formation were; LL, 7.5% (w/w); TR, 8 hours; ST, with 44% stearic acid addition. Omega-3 (5.35%) and omega-6 (1.97%) content in CBE (after interesterification) were not significantly different (p > 0.05) to omega-3 (5.71%) and omega-6 (2.16%) content in initial mixture (before interesterification). The properties of CBE which include POP, POS, SOS, DAG and SMP values were 30.33%, 17.53%, 3.26%, 6.75%, and 46.45°C, respectively under these conditions.

Characterization of Vanaspati Fat Produced in Iran

AbstractVanaspati is the main culinary fat consumed in Iran. It is produced from vegetable oils using different modification processes such as hydrogenation, fractionation, interesterification or blending. To characterize this product, samples from different Iranian brands were collected and their physicochemical properties were studied. Iranian vanaspati contains 0.3–6.2 % trans fatty acids and 24.8–30.5 % saturated fatty acids. Linoleic acid with a range of 32.5–40.3 % is the main unsaturated fatty acid of vanaspati. Iodine values and saponification values of the samples were in the range of 91.9–106.4 and 193.2–194.3, respectively. Free fatty acid contents between 0.04 and 0.10 % and peroxide values between 2.0 and 8.8 mequiv/kg were detected in samples. The induction period of oxidation of the samples was found to be between 8.5 and 15.4 h at 110 °C. With an average slip melting point of 32.9 °C, samples contained 10.0–22.6 % solid fat content at 10 °C, 4.2–10.6 % at 20 °C, 0.3–5.2 % at 30 °C and 0.0–0.5 % at 40 °C. The induction period of crystallization and crystallization rate of samples, were in the range of 0.0–33.11 min and 0.07–2.54 1/min, respectively. Lovibond red and yellow color indices of the product were found to be in the range of 5.0–7.3 and 69.5–70.2, respectively.