<Emphasis Type="Italic">Trans</Emphasis>-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.     

Structured lipids obtained by chemical interesterification of olive oil and palm stearin

Interesterification of palm stearin (PS) with liquid vegetable oils could yield a good solid fat stock that may impart desirable physical properties, because PS is a useful source of vegetable hard fat, providing β′ stable solid fats. Dietary ingestion of olive oil (OO) has been reported to have physiological benefits such as lowering serum cholesterol levels. Fat blends, formulated by binary blends of palm stearin and olive oil in different ratios, were subjected to chemical interesterification with sodium methoxide. The original and interesterified blends were examined for fatty acid and triacylglycerol composition, melting point, solid fat content (SFC) and consistency. Interesterification caused rearrangement of triacylglycerol species, reduction of trisaturated and triunsaturated triacylglycerols content and increase in diunsaturated-monosaturated triacylglycerols of all blends, resulting in lowering of melting point and solid fat content. The incorporation of OO to PS reduced consistency, producing more plastic blends. The mixture and chemical interesterification allowed obtaining fats with various degrees of plasticity, increasing the possibilities for the commercial use of palm stearin and olive oil.     

An investigation on the physicochemical characterization of interesterified blends of fully hydrogenated palm olein and soybean oil

In this study, the effect of interesterification (using sodium methoxide) on physicochemical characteristics of fully hydrogenated palm olein (FHPO)/soybean oil blends (10 ratios) was investigated. Interesterification changed free fatty acid content, decreased oil stability index, solid fat content (SFC) and slip melting point (SMP), and does not affected the peroxide value. With the increase of FHPO ratio, oil stability index, SFC and SMP increased in both the interesterified and non-interesterified blends. Fats with higher FHPO ratio had narrower plastic range, as well. Compared to the initial blends, interesterified fats had wider plastic ranges at lower temperatures. Both the non-interesterified and interesterified blends showed monotectic behavior. The Gompertz function could describe SFC curve (as a function of temperature, saturated fatty acid (SFA) content or both) and SMP (as a function of SFA) of the interesterified fats with high R² and low mean absolute error.     

Production of trans‐free margarine stock by enzymatic interesterification of rice bran oil,palm stearin and coconut oil

BACKGROUND: Trans‐free interesterified fat was produced for possible usage as a spreadable margarine stock. Rice bran oil, palm stearin and coconut oil were used as substrates for lipase‐catalyzed reaction. RESULTS: After interesterification, 137–150 g kg^?1 medium‐chain fatty acid was incorporated into the triacylglycerol (TAG) of the interesterified fats. Solid fat contents at 25 °C were 15.5–34.2%, and slip melting point ranged from 27.5 to 34.3 °C. POP and PPP (β‐tending TAG) in palm stearin decreased after interesterification. X‐ray diffraction analysis demonstrated that the interesterified fats contained mostly β′ polymorphic forms, which is a desirable property for margarines. CONCLUSIONS: The interesterified fats showed desirable physical properties and suitable crystal form (β′ polymorph) for possible use as a spreadable margarine stock. Therefore, our result suggested that the interesterified fat without trans fatty acid could be used as an alternative to partially hydrogenated fat. Copyright © 2010 Society of Chemical Industry     

MELTING CHARACTERISTIC AND SOLID FAT CONTENT OF MILK FAT AND PALM STEARIN BLENDS BEFORE AND AFTER ENZYMATIC INTERESTERIFICATION

Melting characteristics and solid fat content of anhydrous milk fat (AMF), soft palm oil stearin (SPOs), hard palm oil stearin (HPOs) and their blends were studied by differential scanning calorimetry (DSC) and nuclear magnetic resonance (NMR) spectroscopy, respectively. Solid fat contents (SFC) determined by NMR were used to construct isosolid diagrams; these indicated the presence of an eutectic effect along the binary blends of AMF:SPOs which only could be observed at 5 and 10C. The effect was reduced after interesterification by sn-1,3-specific lipase. The modification also reduced the number of the distinct DSC melting peaks, demonstrating a better miscibility among the blended fats. A substantial decrease in DSC melting enthalpy of interesterified blends was found to be parallel to a decrease in SFC that was observed at 25–40C. Fatty acid composition showed that improved functionality of AMF may be due to an enrichment in long-chain saturated fatty acids contributed both by SPOs and HPOs.     

利用酯交换法改进棕榈油硬脂的加工性能

将棕榈油硬脂(ST)与大豆油(SBO)按不同比例混合再进行酯交换反应可以得到不同固脂特征的油脂。实验发现,其中的酯交换油脂IE(70%ST 30%SBO)最适合于加工成通用型起酥油。对这种酯交换油脂的打发性、软硬度及氧化稳定性进行了分析,并与目前市场上常见的全棕榈油基起酥油进行了比较,发现酯交换油脂的柔软度和打发性能均优于后者,但其氧化稳定性不及全棕榈油基起酥油。     

EFFECT OF CHEMICAL INTERESTERIFICATION ON PHYSICOCHEMICAL PROPERTIES AND INDUSTRIAL APPLICATIONS OF CANOLA OIL AND FULLY HYDROGENATED COTTONSEED OIL BLENDS

Blends of canola oil (CO) and fully hydrogenated cottonseed oil (FHCSO), with 20, 25, 30, 35 and 40% FHCSO (w/w) were interesterified under the following conditions: 0.4% sodium methoxide, 500 rpm stirring, 100C, 20 min. The original and interesterified blends were examined for triacylglycerol composition, melting point, solid fat content (SFC) and consistency. Interesterification caused considerable rearrangement of triacylglycerol species, reduction of trisaturated triacylglycerol content and increase in disaturated-monounsaturated and monosaturated-diunsaturated triacylglycerols in all blends, resulting in lowering of respective melting points. The interesterified blends showed reduced SFC at all temperatures and more linear melting profiles if compared with the original blends. Consistency, expressed as yield value, significantly decreased after the reaction. Iso-solid curves indicated eutectic interactions for the original blends, which were eliminated after randomization. The 80:20, 75:25, 70:30 and 65:35 (w/w) CO: FHCSO interesterified blends showed characteristics which are appropriate for their application as soft margarines, spreads, fat for bakery/all-purpose shortenings, and icing shortenings, respectively.

PRACTICAL APPLICATIONS

Recently, a number of studies have suggested a direct relationship between trans isomers and increased risk of vascular disease. In response, many health organizations have recommended reducing consumption of foods containing trans fatty acids. In this connection, chemical interesterification has proven the main alternative for obtaining plastic fats that have low trans isomer content or are even trans isomer free. This work proposes to evaluate the chemical interesterification of binary blends of canola oil and fully hydrogenated cottonseed oil and the specific potential application of these interesterified blends in food products.     

Enzymatic interesterification of palm stearin with Cinnamomum camphora seed oil to produce zero-trans medium-chain triacylglycerols-enriched plastic fat

It is known that Cinnamomum camphora seed oil (CCSO) is rich in medium-chain fatty acids (MCFAs) or medium-chain triacylglycerols (MCTs). The purpose of the present study was to produce zero-trans MCTs-enriched plastic fat from a lipid mixture (500 g) of palm stearin (PS) and CCSO at 3 weight ratios (PS:CCSO 60:40, 70:30, 80:20, wt/wt) by using lipase (Lipozyme TL IM, 10% of total substrate) as a catalyst at 65 °C for 8 h. The major fatty acids of the products were palmitic acid (C16:0, 42.68% to 53.42%), oleic acid (C18:1, 22.41% to 23.46%), and MCFAs (8.67% to 18.73%). Alpha-tocopherol (0.48 to 2.51 mg/100 g), γ-tocopherol (1.70 to 3.88 mg/100 g), and δ-tocopherol (2.08 to 3.95 mg/100 g) were detected in the interesterified products. The physical properties including solid fat content (SFC), slip melting point (SMP), and crystal polymorphism of the products were evaluated for possible application in shortening or margarine. Results showed that the SFCs of interesterified products at 25 °C were 9% (60:40, PS:CCSO), 18.50% (70:30, PS:CCSO), and 29.2% (80:20, PS:CCSO), respectively. The β' crystal form was found in most of the interesterified products. Furthermore, no trans fatty acids were detected in the products. Such zero-trans MCT-enriched fats may have a potential functionality for shortenings and margarines which may become a new type of nutritional plastic fat for daily diet.     

Zero trans shortening using rice bran oil, palm oil and palm stearin through interesterification at pilot scale

Fat blends, formulated by mixing refined, bleached and deodorised (RBD) palm oil (PO) or RBD palm stearin (PS) with RBD rice bran oil (RBO) in various ratios were subjected to chemical interesterification (CIE) at pilot scale using sodium methoxide (NaOMe) as catalyst. The resultant interesterified fat was processed through a margarine crystalliser under optimised conditions. The blends before and after CIE were investigated for triacylglycerol (TAG) composition, solid fat content (SFC) and melting characteristics, polymorphic form, fatty acid composition (FAC), bioactive (tocols, sterols, oryzanol) constituents and trans fatty acids (TFA). CIE was found to be very effective in terms of rearrangement of fatty acids (FAs) among TAGs and consequent changes in the physical characteristics. The SFC of the interesterified PS/RBO blends decreased significantly ( P  ≤ 0.05) when compared with those of PO/RBO blends. The interesterified binary blends with 50–60% PS and 40–50% RBO, and 70–80% PO and 20–30% RBO had SFC curves in the range of all-purpose type shortenings. CIE facilitated the formation of β' polymorphic forms. FAC of shortenings prepared using the optimised blends contained 15–20% C_18:2 polyunsaturated fatty acid (PUFA) and no TFA. Total tocol, sterol and oryzanol content of zero trans shortenings were 650–1145, 408–17 583 and 1309–14 430 ppm. CIE using NaOMe did not affect the bioactive constituents significantly ( P  ≤ 0.05).     

SLIP MELTING POINT ESTIMATION OF FAT BLENDS BEFORE AND AFTER INTERESTERIFICATION BASED ON THEIR FATTY ACID COMPOSITIONS

In this study the relationship between slip melting point (SMP) and fatty acid composition of blends before and after interesterification were investigated. Forty-four blends were prepared using sunflower, canola and cottonseed oils as well as palm stearin and/or fully hydrogenated palm stearin in different proportions. Fatty acid compositions and SMP of samples were determined and then SMP of the blends before and after interesterification were defined as a function of five fatty acids. Specific constants of C_16:0, C_18:0, C_18:1, C_18:2 and C_18:3 fatty acids were determined as 0.455, 0.821, 0.622, 0.215 and -1.653, respectively, for the blends before interesterification and 0.532, 0.614, 0.399, 0.055 and -2.471, respectively, for the blends after interesterification by using least squares method. Slip melting point of blends were calculated using these constants and fatty acid compositions and then compared with the experimental values. No linear relationship existed between the calculated and experimental results of the blends before interesterification, but SMP of the blends after interesterification could be estimated with high (r=0.956) accuracy.     

Enzymatic interesterification of palm and coconut stearin blends

Hard fractions of palm oil and coconut oil, blended in the ratios of 90:10, 85:15, 80:20 and 75:25, were interesterified for 8 h using Lipozyme TL IM. Major fatty acids in the blends were palmitic acid (41.7–48.4%) and oleic acid (26.2–30.8%). Medium‐chain fatty acids accounted for 4.5–13.1% of the blends. After interesterification (IE), slip melting point was found to decrease from 44.8–46.8 °C to 28.5–34.0 °C owing to reduction in solids content at all temperatures. At 37.5 °C, the blends containing 25% coconut stearins had 17.4–19% solids, which reduced to 0.4–1.5% on IE, and the slip melting point (28.6 and 28.8 °C) indicated their suitability as margarine base. The reduction in solid fat index of the interesterified fats is attributed to the decrease in high‐melting triacylglycerols in palm oil (GS₃ and GS₂U type) and increase in triolein (GU₃) content from 1 to 9.2%. Retention of tocopherols and β‐carotene during IE was 76 and 60.1%, respectively, in 75:25 palm stearin and coconut stearin blend.     

基于酶促酯交换的速冻专用油脂制备及应用研究

利用脂肪酶Lipozyme TL IM催化质量比为7:3的棕榈硬脂与大豆油进行酯交换反应,混合油脂中的高熔点甘三酯三棕榈酸甘油酯(PPP)的含量从27.61%降至9.50%。以酯交换油为主体,设计了5种不同塑性范围和固体脂肪含量的基料油,并以此基料油为原料制备出5种速冻专用油脂,然后将之应用于制作速冻汤圆。结果表明,当基料油中的油脂配比为酯交换油:大豆油:棕榈硬脂=84:13:3(wt%)时,所制备的专用油脂具有最佳的抗冻性能,以之制作的速冻汤圆冻裂率最低,仅为5%,而应用市售速冻专用油脂、未酯交换油脂制备的速冻专用油脂、未添加速冻专用油脂制作的的汤圆冻裂率分别为30%、20%和50%;此外,所得速冻汤圆表面细腻,光洁,有弹性,口感好,感官评分最高,表明通过酶促酯交换反应可以制备出品质优良的速冻专用油脂。     

Synthesis of confectionery fat from illipé butter stearin and palm mid-fraction blend via enzymatic interesterification

Cocoa butter equivalent (CBE) was synthesised from blends of illipé butter stearin (IBS) and palm mid-fraction (PMF) via enzymatic interesterification (EIE). IBS was blended with PMF in three wt ratios (70:30, 60:40 and 50:50) and the EIE reactions were performed at 50°C for 30 min using an sn-1,3-specific lipase from Rhizopus oryzae as a catalyst. The triacylglycerol (TAG) compositions, slip melting points (SMP), crystallisation and melting thermograms, solid fat content (SFC) curves, and crystal microstructure of the blends before and after EIE were studied and compared with cocoa butter (CB). After EIE, the contents of POP and StOSt decreased, whereas the POSt content increased in all blends. Blend EIE 60:40 exhibited the POP and StOSt contents that situated within the ranges of POP and StOSt contents of CB. It also showed SMP, melting peak and melting completion temperatures, melting enthalpy and crystal microstructure most similar to CB. Most importantly, its SFC curve completely matched that of CB. Consequently, EIE 60:40 was chosen for further investigation and it was found to be fully compatible with CB and crystallised into the same polymorphic form (β) as CB. Therefore, EIE 60:40 has a high potential for use as a commercial CBE.     

Utilization of interesterified oil blends in the production of frankfurters

Ten treatments of frankfurters were produced with interesterified oil and oil blends (palm oil, palm stearin, cottonseed oil, hazelnut oil and their mixtures) and were compared to control, produced with all animal fat. Addition of interesterified oil and oil blends affected (p < 0.05) the moisture and fat content and pH values of frankfurters. According to the colour measurements, the brightness value (L^∗) of most of the samples with interesterified oil and oil blends were higher (p < 0.05) than the control. The fatty acid composition of frankfurters was modified. The PUFA/SFA values of frankfurters were increased due to the presence of interesterified oil and oil blends in the formulation. Frankfurters with 100% interesterified cottonseed oil or with interesterified oil blends with 66.6% and 83.4% cottonseed oil had PUFA/SFA ratio higher than 0.4 and are considered better than all others from the health point of view. Frankfurters produced with 100% interesterified cottonseed and hazelnut oil or with interesterified hazelnut oil blends had the same (p > 0.05) scores for sensory attributes with the control, while all other treatments were also acceptable.     

Effects of chemical interesterification on physicochemical properties of blends of palm stearin and palm olein

Chemical interesterification is an important technological option for the production of fats targeting commercial applications. Fat blends, formulated by binary blends of palm stearin and palm olein in different ratios, were subjected to chemical interesterification. The following determinations, before and after the interesterification reactions, were done: fatty acid composition, softening point, melting point, solid fat content and consistency. For the analytical responses a multiple regression statistical model was applied. This study has shown that blending and chemical interesterifications are an effective way to modify the physical and chemical properties of palm stearin, palm olein and their blends. The mixture and chemical interesterification allowed obtaining fats with various degrees of plasticity, increasing the possibilities for the commercial use of palm stearin and palm olein.     

Scaled-up production of zero-trans margarine fat using pine nut oil and palm stearin

An interesterified structured lipid was produced with a lipid mixture (600 g) of pine nut oil (PN) and palm stearin (PS) at two weight ratios (PN:PS 40:60 and 30:70) using lipase (Lipozyme TL IM, 30 wt.%) as a catalyst at 65 ^°C for 24 h. Major fatty acids in the interesterified products were palmitic (35.1–40.4%), oleic (29.5%), and pinolenic acid (cis-5, cis-9, cis-12 18:3; 4.2–5.9%). α-Tocopherol (1.1–1.3 mg/100 g) and γ-tocopherol (0.3–0.4 mg/100 g) were detected in the interesterified products. Total phytosterols (campesterol, stigmasterol, and β-sitosterol) in the interesterified products (PN:PS 40:60 and 30:70) were 63.2 and 49.6 mg/100 g, respectively. Solid fat contents at 25 ^°C were 23.6% (PN:PS 40:60) and 36.2% (PN:PS 30:70). Mostly β′ crystal form was found in the interesterified products. Zero-trans margarine fat stock with desirable properties could be successfully produced from pine nut oil and palm stearin.     

Use of enzymatic transesterified palm stearin-sunflower oil blends in the preparation of table margarine formulation

Palm stearin–sunflower oil (PS:SO) blends, formulated by mixing 40 to 80% palm stearin in increments of 10% (w/w), were subjected to transesterification catalysed by lipases from Pseudomonas sp. and Rhizomucor miehei (Lipozyme 1M 60). The physical properties of the transesterified products were evaluated by slip melting point (SMP), differential scanning calorimetry (DSC), solid fat content (SFC) and X-ray difflaction (XRD) analyses. SMP results indicate that Pseudomonas lipase caused a bigger drop in SMP (33%) in the PS–SO (40:60) blend than the R. miehei-lipase-catalysed reaction blend (13%). The Pseudomonas-catalyzed blends of PS-SO, at 40:60 and 50:50 ratios, showed complete melting at 37 and 40°C, respectively, while the R. miehei-catalyzed PS–SO blend at 40:60 ratio had a residual SFC of 3.9% at 40°C. Pseudomonas lipase also successfully changed the polymorphic form(s) in the unreacted PS–SO mixture from a predominantly β form to a predominantly β′ form in the transesterified blends. However, no changes in polymorphic forms were observed after transesterification with R. miehei lipase (as against to the unreacted PS–SO blends). These results suggest that the Pseudomonas lipase caused a greater randomization and diversification of fatty acids, particularly palmitic acids, in palm stearin with the unsaturated fatty acids from sunflower oil than did R. miehei lipase. Based on the physical characteristics, the Pseudomonas-catalyzed 40:60 and 50:50 PS:SO blends would be the two most suitable blends to be used as table margarine formulations.     

Directed interesterification of a brazilian palm oil and analysis of the original and interesterified oil and its fractions

A commercial sample of the Brazilian palm oil from the north eastern State of Bahia after neutralisation, washing and drying was interesterified in the presence of sodium-potassium alloy (NaK) at 30°C in a nitrogen atmosphere. The catalyst was destroyed by addition of water in a carbon dioxide atmosphere and the interesterified oil was crystallised from light petroleum, yielding an olein and stearin fraction. The fatty acid and triacylglycerol composition of the neutralised oil was determined by gas chromatography (g.c.) and high-performance liquid chromatography (h.p.l.c.) respectively and was shown to be similar to that of Malaysian and African palm oil. The compositions of the interesterified Brazilian oil and its liquid and solid fractions were also determined. The physicochemical characteristics of the olein obtained by interesterification with NaK, such as iodine value (96.8) and its softening point (below ?8°C) indicated its suitability for the use as salad oil.     

Lipase-catalysed interesterification between canola oil and fully hydrogenated canola oil in contact with supercritical carbon dioxide

The processing parameters in enzymatic reactions using CO₂-expanded (CX) lipids have strong effects on the physical properties of liquid phase, degree of interesterification, and physicochemical properties of the final reaction products. CX-canola oil and fully hydrogenated canola oil (FHCO) were interesterified using Lipozyme TL IM in a high pressure stirred batch reactor. The effects of immobilised enzyme load, pressure, substrate ratio and reaction time on the formation of mixed triacylglycerols (TG) from trisaturated and triunsaturated TG were investigated. The optimal immobilised enzyme load, pressure, substrate ratio and time for the degree of interesterification to reach the highest equilibrium state were 6% (w/v) of initial substrates, 10 MPa, blend with 30% (w/w) of FHCO and 2 h, respectively. The physicochemical properties of the initial blend and interesterified products with different FHCO ratios obtained at optimal reaction conditions were determined in terms of TG composition, thermal behaviour and solid fat content (SFC). The amounts of saturated and triunsaturated TG decreased while the amounts of mixed TG increased as a result of interesterification. Thus, the interesterified product had a lower melting point, and broader melting and plasticity ranges compared to the initial blends. These findings are important for better understanding of CX-lipid reactions and for optimal formulation of base-stocks of margarine and confectionary fats to meet industry demands.     

Ultrasound Doppler based in‐line viscosity and solid fat profile measurement of fat blends

This study reports the use of upgraded ultrasonic velocity profiling with pressure difference methodology; extended from previous work demonstrating true in‐line rheological and solid fat content (SFC) characterisation of complex opaque fat blends, subjected to scaled dynamic processing conditions. The experimental results have successfully confirmed previous non‐invasive, in‐line measurements for instantaneous velocity and rheological profiling of complex opaque fat blends [International Journal of Food Science and Technology 43 (2008) 2083]. A method for in‐line measurements under dynamic processing conditions to obtain the SFC of a fat blend was developed and successfully tested for a 30% palm stearin and 70% rapeseed oil system over a temperature range of 10–40 °C. These measurements correlated well with standard SFC values from pulsed‐nuclear magnetic resonance (p‐NMR) measurements deviating not more than +/– 2% SFC points from the standard p‐NMR values.