Effect of emulsion temperature on physical properties of palm oil-based margarine

Margarines made from refined, bleached, and deodorized palm oil at different emulsion temperatures showed no significant difference in their consistency, polymorphic behavior, and solid fat content (SFC) during storage, although differences were observed during processing. The emulsion temperatures studied were 40, 45, and 50°C, with other parameters such as emulsion flow rates, tube cooler temperature, and pin rotor speed kept constant. The SFC developed during processing and storage at 28°C was measured to evaluate the quality of margarine. The emulsion contained no SFC at any emulsion temperature studied. However, the amount of SFC in the perfector or tube cooler unit increased to 15.9, 13.9, and 15.6% in margarine produced at emulsion temperatures of 40, 45, and 50°C, respectively. At 40°C, the lowest SFC was developed during storage even though this margarine had the highest consistency. The softening point of this sample was moderately high and closely related to the type of crystal developed, which was a mixture of β′ and β crystals. Emulsion at 45°C gave the most stable margarine consistency and SFC with crystal in the β′ form even after the fourth week. At 50°C, moderately soft product was produced, which might be undesirable for some applications, although the crystals were in the β′ form.     

Preparation and Characterization of a Zero-trans Margarine

Two new types of margarines were prepared in this study. The first was processed without the traditional milk flavour. The fat phase consists of 40% partially hydrogenated cottonseed oil (m. p. 42.2°C), 40 % cottonseed oil and 20 % olive oil as a source of flavouring and antioxidant materials. The second margarine was based mainly on the interesterified fat formed from lipase interesterification of a mixture of 86.5 % cottonseed oil and 13.5 % fully hydrogenated soybean oil (m. p. 67.2°C). Characterization and evaluation of these new types of margarines in relation to two conventional margarines are reported. The presence of diglycerides in the interesterified fat (free from trans isomers) reduced the amount of crystallized solids and the properties of the product were very close to conventional soft margarines. Margarine with olive oil taste was well accepted.     

Chemical and physical properties of the high melting glyceride fractions of commercial margarines

The fat obtained from nine commercial mar-garines purchased from Canada and the U.S.A. were crystallized from acetone at 15, 10, 5 and 0°C. The high melting triglyceride (HMG) fractions at 15°C contained high levels of palmitic and stearic acids. The 18:1 levels increased as fractionation temperature decreased. Triglyceride analysis re-vealed that the 11MG fractions contained high 1ev-els of carbon 54 and 52. The levels of trans iso-mers increased, whereas the trans levels in the 18:1 decreased with fractionation temperature. Mar-games made from canola oil exhibited β charac-teristics whereas canola-paim, soybean and corn margarines showed β¹ crystals. The fractions as crystallized from acetone, showed numerous X-ray short spacings, characteristic of β¹, β and in-termediate forms. Upon heating and cooling, the 15°C fraction showed β¹ or a and β¹ characteris-tics regardless of the polymorphic form present in the original margarines. The differential scan-ning calorimetry (DSC) melting points of these fractions varied from 53 to 50° C. The difference between the β and β¹ margarines could be related to the 16:0 and carbon 54 content of the 15°C frac-tion. In the β tending margarines the 16:0 content was below 11%, in the β¹ tending margarines above 17%. The carbon 54 content in the 15°C fraction of the β tending margarines was close to 70% and that of the β¹ tending margarines around 50%. The triglyceride C54 in the 15°C fraction is β tending and therefore should be kept as low as possible. In canola margarines this can be achieved by in-corporation of palm oil, preferably in a slightly hydrogenated form. Presented at the Annual Meeting, Canadian Section of AOCS, October, 1989, Halifax, Canada.     

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.     

Potential margarine oils from genetically modified soybeans

Genetically modified soybeans were processed into finished, refined, bleached, and deodorized oils. Fatty acid composition was determined by gas-liquid chromatography. Glyceride structure was characterized according to degree of unsaturation by high-performance liquid chromatography, lipase hydrolysis, and gas-liquid chromatography. Compared to common varieties with 15% saturated acids, genetically modified soybeans yielded oils containing 24–40% saturated acids. Several varieties were examined, including the Pioneer A-90, Hartz HS-1, and Iowa State A-6 lines. Pioneer A-90 contained 17% stearic acid, had a solid fat index (SFI) of 6.0 at 10°C (50°F) and zero from 21.1 to 40°C (70 to 104°F), and therefore lacked sufficient solids for tub-type margarine. To improve its plastic range, the Pioneer oil was blended with palm oil, randomized palm oil, or interesterified palm/soy trisaturate basestock. After blending with 10–40% of these components, the high-stearic acid oil had an SFI profile suitable for soft tube margarine. The A-6 varieties, 32–38% saturates, showed SFI profiles with sufficient solids at 10°C (50°F) and 21.1°C (70°F) to qualify as a stick-type margarine oil, but lacked sufficient solids at 33.3°C (92°F); however, after small amounts (2–3%) of cottonseed or soybean hardstocks were added, the A-6 oils qualified as stick margarine oil. The HS-1 variety, when blended with small amounts (2–3%) of hardstock, possessed sufficient solids at 10°–33.3°C (50–92°F) to prepare soft tub margarine oil. Presented at the AOCS Annual Meeting & Expo, San Antonio, Texas, May 8–12, 1995.     

Formation of Granular Crystals in Margarine with Excess Amount of Palm Oil

Crystallization behavior of palm oil and tripalmitin (PPP) in a model margarine system was investigated. The model margarine was held in a programmable oven, heated to 5 °C for 12 h and then 20 °C for a further 12 h. After 3 weeks, the model margarine was evaluated by polarization microscopy. Granular crystals were observed in the margarine containing an excess amount of palm oil and PPP. The concentration of higher-melting fatty acids was higher in the crystals relative to the surroundings. Likewise, the presence of lower-melting fatty acids was lower in the crystals. The polymorphic structure of the margarine with excess palm oil and PPP was determined to be all β′ by X-RD spectra. The result suggested that the agglomeration of higher-melting point triglycerides (TAGs), such as PPP in this study, led to the formation of granular crystals in the margarine without β polymorphic emergence.     

Comparison of lipase-transesterified blend with some commercial solid frying shortenings in Malaysia

A transesterified experimental solid frying shortening was prepared from a palm stearin/palm kernel olein blend at 1∶1 ratio (by weight) by using Rhizomucor miehei lipase at 60°C for 6 h. The fatty acid (FA) and triacylglycerol compositions, polymorphic forms, melting and cooling characteristics, slip melting point (SMP), and solid fat content (SFC) of the transesterified blend were then compared with five commercial solid frying shortenings (three domestic and two imported) found in Malaysia. All the domestic shortenings contained nonhydrogenated palm oil or palm olein and palm stearin as the hard stock, whereas the imported frying shortenings were formulated from soybean oil and cottonseed oil and contained high level of β′ crystals. Trans FA were also found in these samples. The lipase-transesterified blend was found to be more β′-tending than the domestic samples. The SMP of the transesterified blend (47.0°C) fell within the range of the domestic samples (37.8–49.7°C) but was higher than the imported ones (42.3–43.0°C). All samples exhibited similar differential scanning calorimetry cooling profiles, with a narrow peak at the higher temperatures and a broad peak at the lower temperatures, even though their heating thermograms were quite different. Imported samples had flatter SFC curves than both the experimental and domestic samples. The domestic samples were found to have better workability or plasticity at higher temperatures than the imported ones, probably because they were formulated for a tropical climate.     

Physicochemical,Textural and Viscoelastic Properties of Palm Diacylglycerol Bakery Margarine During Storage

Physicochemical, textural and viscoelastic properties of palm diacylglycerol (PDG) bakery margarines (DOS720, DOS721 and DOS711) and commercial margarine (CM) throughout a 3-month storage period were evaluated and compared. All the margarines had significant (P < 0.05) increments in slip melting point (SMP), solid fat content (SFC) and hardness during storage with CM having the highest overall increment followed by margarines DOS711, DOS 721 and DOS720. The smaller increments are mainly due to the ability of PDG to delay polymorphic transformation from β′ to β form. In terms of viscoelastic properties, all margarines had a higher degree of firmness which may probably be due to rearrangement of the fat crystals into a three-dimensional scaffolding network upon storage. In terms of melting behavior, storage has no effects on all margarines with the exception of margarine DOS711. The melting behavior of margarine DOS711 displayed a probability of oil exudation during storage. As for polymorphic transformation, CM had the earliest polymorphic transformation with only β crystals after 8 weeks of storage. PDG bakery margarines managed to retard the transformation to more than 10 weeks of storage for DOS711 and 12 weeks of storage for DOS720 and DOS721.     

Chemical and physical properties of the solid fats in commercial soft margarines

The fats of ten Canadian soft margarines were crystallized from acetone at 15°C to obtain the high-melting glycerides (HMG). The solid fats in the margarines were extracted with isboutanol at 5°C. X-ray diffraction showed that the canola margarines were in the β crystal form, the soybean and sunflower-palm-palm kernel margarines in the β′ form, while those of canola-palm and another sunflower-palm-palm kernel margarines contained a mixture of β′ and β forms. X-ray diffraction of the isolated solids showed additional short spacings compared with those of the original margarines. Differential scanning calorimetry heating curves of the solids were compared with those of the HMG. The melting temperatures of the HMG were 10°C higher than the solids. It is suggested that the polymorphic behavior of soft margarines is related to the chemical composition of the HMG and the solids. Solids in margarines can also be provided by interesterification of palm oil products. Presented at the Annual Meeting, Canadian section of AOCS, October 18–19, 1990, Toronto, Canada.     

Interesterification of tea seed oil and its application in margarine production

Blends of hydrogenated and nonhydrogenated tea seed oil (Lahijan variety) (30:70, w/w) were chemically interesterified at 60, 90, and 120°C for 30, 60, and 90 min in the presence of 1% (w/w) NaOH. Physicochemical properties of the products were compared with those of the noninteresterified mixture. Statistical comparison of m.p., iodine values (IV), and solid fat contents (SFC) showed that the sample having the highest ranking was interesterified at 120°C for 30 min. The sample was used as a hardstock (40%), with liquid tea seed oil and sunflower oil (ratios of 100:0, 80:20, 60:40, 40:60, 20:80, and 0:100) as, a softstock (60%) for production of table magarine, and the properties of these margarines were compared with those of commercial ones. Samples E and D (ratio of 80:20 and 60:40 liquid tea seed oil/sunflower oil, respectively) had the lowest significant differences with commercial table margarine for physicochemical (m.p., IV, and SFC) and organoleptic characteristics, respectively. Generally, based on m.p. and SFC, margarines E and D were classified as soft margarine. The trans FA content of E, D, and commercial margarines were 1.8, 1.8, and 2.2%, respectively.     

Physicochemical and textural properties of puff pastry margarines

In this paper some physicochemical and textural characteristics of four puff pastry margarines are defined: MLT1 and MLT2 with low trans fatty acid (TFA) content, MLT3 with relatively low and MLT4 with high TFA content. Analyzing the solid trigliceride content (SFC), the crystallization kinetics in isothermal conditions and the margarine firmness, it is determined whether the technological characteristics of margarines (which are very important for puff pastry quality) are significantly changed due to TFA decrease in margarines. The highest SFC at 10, 20, 25 i 30°C have samples MLT1 and MLT4. Despite of significant differences in fatty acid composition of these margarines, SFC content at temperatures at 20, 25, and 30°C do not differ significantly, at the level of significance of 95% (p>0.05). The SFC of MLT1 and MLT2 samples, which have practically the same fatty acid composition at every investigated temperature, statistically have significant difference (p<0.05). The crystallization kinetics are in the range from 2.6 to 10.1% per min. The significance of the induction period at every observed samples is negligible. The average firmness of margarine samples MLT1, MLT2, MLT3, and MLT4 at 20, 25, and 30°C is significantly different (p<0.05). The firmness changes of the samples MLT1 and MLT2 in the most important temperature interval for puff pastry production (between 20 and 30°C) are at level of 5 to 25%, and for margarine samples MLT3 and MLT4 these values reach even 70%.     

Polymorphic stability of hydrogenated palm oleins in dilutions with unhydrogenated liquid oils

Palm oil was hydrogenated under selective and nonselective conditions. Some of the hydrogenated samples were chosen for their physical characteristics and were diluted with 70% sunflower oil. A commercial hydrogenated palm olein (H-olein) was diluted up to 80% with canola oil. The diluted mixtures were evaluated for their polymorphic β' stability by a temperature-cycling procedure between 4 and 20°C. All of the mixtures were stable in the β' form. The dropping point and solid fat content of the mixtures were compared with those of commercial soft and stick margarines. Soft margarines can be prepared from mixtures of 20% H-olein and 80% unhydrogenated oil, and stick margarines from 40% H-olein and 60% liquid oil. If canola oil is the liquid oil, the saturated content in the soft formulation is 13% and that of a stick formulation 17%.     

Changing trends in consumer margarines

Margarine has changed dramatically from 100 years ago when it was first made as a butter substitute. It is now a high technology product with many mutations and variations. There are ten different types of margarine produced today. There are regular, whipped, and polyunsaturated margarines in both stick and soft forms. There are diet margarines, liquid margarines, and new 60% vegetable oil spreads. These margarines are made from a variety of oils including soybean, cottonseed, palm, corn, safflower, and sunflower oils. These tailor-made products cater to the needs of many different segments of the population. This marketing strategy has helped to create increasing consumer demand over the years. Presented at the AOCS Meeting, New York, May 1977.     

Relationship between slip melting point and pulsed NMR data of palm kernel oil

A quantitative relationship between slip melting point (SMP) of palm kernel oil and pulsed nuclear magnetic resonance (NMR) data was established. Regression analysis on the SMP and solid fat content (SFC) data by NMR afforded the following relationship: SMP (°C) = 0.03278 X (SFC 10) + 0.1458 X (SFC 20) + 19.1738 where SFC 10 was the solid fat content (%) at 10°C and SFC 20 was the solid fat content (%) at 20°C. The coefficient of multiple correlation was 0.87871. The equation was tested with 12 samples of crude and refined palm kernel oil. SMPs as determined indirectly by NMR correlated well with the conventional open capillary tube results (r = 0.99998). The maximum difference observed was 0.3°C. The correlation can be applied usefully for quality control.     

Composition and thermal profile of crude palm oil and its products

Gas-liquid chromatography and high-performance liquid chromatography (HPLC) were used to determine fatty acids and triglyceride (TG) compositions of crude palm oil (CPO), refined, bleached, and deodorized (RBD) palm oil, RBD palm olein, and RBD palm stearin, while their thermal profiles were analyzed by differential scanning calorimeter (DSC). The HPLC chromatograms showed that the TG composition of CPO and RBD palm oil were quite similar. The results showed that CPO, RBD palm oil, RBD olein, and superolein consist mainly of monosaturated and disaturated TG while RBD palm stearin consists mainly of disaturated and trisaturated TG. In DSC cooling thermograms the peaks of triunsaturated, monosaturated and disaturated TG were found at the range of −48.62 to −60.36, −25.89 to −29.19, and −11.22 to −1.69°C, respectively, while trisaturated TG were found between 13.72 and 27.64°C. The heating thermograms of CPO indicated the presence of polymorphs β₂′, α, β₂′, and β₁. The peak of CPO was found at 4.78°C. However, after refining, the peak shifted to 6.25°C and became smaller but more apparent as indicated by RBD palm oil thermograms. The heating and cooling thermograms of the RBD palm stearin were characterized by a sharp, high-melting point (high-T) peak temperature and a short and wide low-melting point (low-T) peak temperature, indicating the presence of occluded olein. However, for RBD palm olein, there was only an exothermic low-T peak temperature. The DSC thermograms expressed the thermal behavior of various palm oil and its products quite well, and the profiles can be used as guidelines for fractionation of CPO or RBD palm oil.     

Modification of margarine fats by enzymatic interesterification: Evaluation of a solid-fat-content-based exponential model with two groups of oil blends

Lipozyme TL IM-catalyzed interesterification for the modification of margarine fats was carried out in a batch reactor at 70°C with a lipase dosage of 4%. Solid fat content (SFC) was used to monitor the reaction progress. Lipase-catalyzed interesterification, which led to changes in the SFC, was assumed to be a first-order reversible reaction. Accordingly, the change in SFC vs. reaction time was described by an exponential model. The model contained three parameters, each with a particular physical or chemical meaning: (i) the initial SFC (SFC₀), (ii) the change in SFC (ΔSFC) from the initial to the equilibrium state, and (iii) the reaction rate constant value (k). SFC_o and ΔSFC were related to only the types of blends and the blend ratios. The rate constant k was related to lipase activity on a given oil blend. Evaluation of the model was carried out with two groups of oil blends, i.e., palm stearin/coconut oil in weight ratios of 90∶10, 80∶20, and 70∶30, and soybean oil/fully hydrogenated soybean oil in weight ratios of 80∶20, 65∶35, and 50∶50. Correlation coefficients higher than 0.99 between the experimental and predicted values were observed for SFC at temperatures above 30°C. The model is useful for predicting changes in the SFC during lipase-catalyzed interesterification with a selected group of oil blends. It also can be used to control the process when particular SFC values are targeted.     

Dispersed phase destabilization in table spreads

Commercially available butter, regular-fat margarine, and a fat-reduced margarine (38% fat w/w) were stored between 10 and 35°C for up to 4 d to elaborate on the relationship between droplet size and solid fat content (SFC) that exists in these spreads. At 10°C, the mean volume-weighted droplet size for butter was 4.22±0.40 μm followed by margarine (6.22±0.10 μm) and fat-reduced margarine (12.62±0.28 μm). At higher temperatures, as a result of decreasing SFC, the mean droplet size increased as did the droplet size distribution, leading to eventual coalescence and destabilization in all spreads. In butter, the critical SFC was ∼9%, whereas in margarine notable coalescence occurred at ∼5% SFC. The fat-reduced margarine destabilized at lower temperatures than the other spreads (∼20°C vs. ∼30°C), at an SFC of ∼6.5%. In these spreads, two different mechanisms influenced dispersed phase stability: (i) steric stabilization against coalescence via fat crystals located at the droplet interface, known as Pickering stabilization, and (ii) stabilization against droplet sedimentation (and droplet encounters) due to the presence of the fat crystal network.     

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.     

Rheological Properties of Sunflower Margarine

The consistency of margarine is affected by a number of different factors. The governing factors are particularly the formulation of the margarine fat and technology parameters of the processing. The effect of the margarine fat formulation on rheological properties of margarine made under constant conditions on a laboratory equipment was studied. In soft margarines to be used directly as spreads, their spreadability even at lower temperatures during the storage in refrigerator is of importance, which means that their rheological parameters (static and dynamic yield value, apparent viscosity) should be independent of temperature as little as possible in a temperature interval of 5 to 25°C. The experiments performed indicated that under the constant conditions of a laboratory preparation used, optimum rheological properties were achieved with samples prepared from a margarine fat with a composition of the 50–65% soft sunflower oil and 35–50% hardened sunflower oil 36°C.     

Provitamin a activity and stability of β-carotene in margarine

Summary Samples of synthetic β-carotene have been assayed for vitamin A activity by the rat-curative, growth method against vitamin A acetate and compared with natural carotene. The U.S.P. XIV diet was modified by the addition of vitamin B₁₂ and α-tocopherol, which have been reported to enhance carotene utilization. Doses of vitamin A and carotene were given in cottonseed oil and in margarine; but, contrary to the report of Deuelet al. (13), no significant increase was observed in the utilization of carotene fed in margarine. The samples tested include crystalline all-trans β-carotene, micropulverized all-trans β-carotene in an oil suspension, and a series of 10 commercial margarines fortified with vitamin A. and carotene in a ratio of about 2 I.U. of vitamin A to 1 I.U. of carotene. In terms of vitamin A activity in the rat bioassay, the average potency of β-carotene in three separate bioassays of crystalline carotene was found to be 1,730,000 I.U. per gram with a standard error of ±3.5%. Thus in these assays 1 I.U. of vitamin A activity was found to be equivalent to 0.58 mcg. of all-trans β-carotene, a value in essential agreement with 0.6 mcg., the presently accepted International Standard. For margarine samples containing vitamin A and β-carotene, the average vitamin A activity in 2 bioassays was found to be very close to that calculated from the colorimetric assays, using the factor for β-carotene, 0.6 mcg.=1 I.U. The fact that other workers have reported higher provitamin A activity for β-carotene in the rat bioassay indicates the dependence of the results on the particular conditions of the bioassay. The stability of vitamin A and β-carotene in commercially prepared margarines stored at 40°F. and 75°F. was studied by accepted colorimetric procedures. Average retention values of 94% or better were obtained in margarines stored two months when the vitamin activity was supplied either from β-carotene or from vitamin A.