Effects of chemical interesterification on solid fat content and slip melting point of fat/oil blends

Fat/oil blends, formulated by mixing fully hydrogenated palm oil stearin or palm oil stearin with vegetable oils (canola oil and cottonseed oil) in different ratios from 30:70 to 70:30 (w/w %), were subjected to chemical interesterification reactions on a laboratory scale. Fatty acid (FA) composition, iodine value, slip melting point (SMP) and solid fat content (SFC) of the starting blends were analysed and compared with those of the interesterified blends. SMPs of interesterified blends were decreased compared to starting blends because of extensive rearrangement of FAs among triacylglycerols. These changes in SMP were reflected in the SFCs of the blends after the interesterification. SFCs of the interesterified blends also decreased with respect to the starting blends, and the interesterified products were softer than starting blends. These interesterified blends can be used as an alternative to partial hydrogenation to produce a plastic fat phase that is suitable for the manufacture of margarines, shortenings and confectionary fats.     

Production of zero trans Iranian vanaspati using chemical transesterification and blending techniques from palm olein, rapeseed and sunflower oils

Chemical transesterification and blending techniques were used for producing zero trans fats suitable for use as Iranian vanaspati. Triple blends of palm olein (POo), rapeseed (RSO) and sunflower oil (SFO) were subjected to two different treatments: (i) blending and then transesterification (BT) and (ii) transesterification of pure POo before blending with RSO and SFO (TB). The changes in slip melting point (SMP), solid fat content (SFC), carbon number (CN) triacylglycerol (TAG) composition, induction period (IP) of oxidation at 120 °C and IP of crystallisation at 20 °C of blends before and after treatments were investigated. Both BT and TB methods resulted in an increase in the CN48 TAG molecules, SMP and SFC, and a decrease in the IP of oxidation and crystallisation of initial blends. Samples made by TB method had higher CN48 TAG content, SMP, SFC and IP of oxidation, and lower IP of crystallisation than those made by BT method. Correlation between SFC at 20 °C and saturated fatty acid (SFA) content of the treated blends indicated that the SFA must be higher than 33.1% and 26.8% for BT and TB methods, respectively, to obtain fats suitable for use as vanaspati.     

Trans-free Iranian vanaspati through enzymatic and chemical transesterification of triple blends of fully hydrogenated soybean,rapeseed and sunflower oils

Production of trans-free Iranian vanaspati through enzymatic and chemical transesterification of triple blends of fully hydrogenated soybean (FHSBO), rapeseed (RSO) and sunflower (SFO) oils was investigated. The slip melting point (SMP), solid fat content (SFC) at 10–40 °C and induction period of oxidation at 120 °C (IP₁₂₀) of the transesterified and initial blends were evaluated. Results indicated that all the enzymatically and chemically transesterified blends had lower SMP, SFC and IP₁₂₀ than their initial blends. No significant differences (P < 0.05) were observed between the SMP of enzymatically and chemically transesterified blends. Some enzyme treated blends had higher SFC at some temperatures than chemically transesterified ones. Enzymatically transesterified blends had higher IP₁₂₀ than those prepared by chemical transesterification. Correlation between SFC at 20 °C and saturated fatty acid (SFA) content, and between SMP and SFA of transesterified blends indicated that the SFA must be between 27.2% and 36.6% for enzymatic and 28.4% and 37.8% for chemical transesterification to obtain transesterified fats suitable for use as vanaspati.     

Improvement of palm oil and sunflower oil blends by enzymatic interestrification

Palm oil (PO) and sunflower oil (SFO) blends with varying proportions were subjected to enzymatic interesterification (EIE) using a 1,3‐specific immobilised lipase. The interesterified blends were evaluated for their slip melting point (SMP), solid fat content (SFC) at 10–40 °C, p‐anisidine value, peroxide value, free fatty acids (FFA), induction period of oxidation at 110 °C (IP110) and composition of fatty acids by gas chromatography. Under EIE treatment, the blends of PO and SFO in different proportions (20:80, 40:60, 50:50, 60:40 and 80:20) had saturated and unsaturated fatty acid content in the range of 37.6–52.0% and 48.0–62.4%, respectively. The blends showed a considerable reduction in their SFC, SMP, peroxide value and oxidative stability at 110 °C, but presented increase in FFA and p‐anisidine value. The optimum condition for minimising the fatty acid in oil was obtained, at 64 °C, using 8.9% enzyme and 3 h reaction time.     

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.     

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.     

Characterisation of zero‐trans margarine fats produced from camellia seed oil,palm stearin and coconut oil using enzymatic interesterification strategy

Zero‐trans interesterified fats were produced from camellia seed oil (CSO), palm stearin (PS) and coconut oil (CO) with three weight ratios (CSO/PS/CO, 50:50:10, 40:60:10 and 30:70:10) using Lipozyme TL IM. Results showed that the interesterified products contained palmitic acid (34.28–42.96%), stearic acid (3.96–4.72%), oleic acid (38.73–47.95%), linoleic acid (5.92–6.36%) and total medium‐chain fatty acids (MCFA)s (∑MCFAs, 5.03–5.50%). Compared with physical blends, triacylglycerols of OOO and PPP were decreased and formed new peaks of equivalent carbon number (ECN) 44 in the interesterified products. The product CPC3′ showed a slip melting point of 36.8 °C and a wide plastic range of solid fat content (SFC) (45.8–0.4%) at 20–40 °C. Also, the major β′ form was determined. These data indicated that the zero‐trans interesterified fats would have a potential functionality for margarine fats. Subsequently, the antioxidative stabilities of interesterified products with the addition of α‐tocopherol (α‐TOH) and ascorbyl palmitate (AP) were investigated. The results indicated that AP had a dose‐dependent effect at concentrations of 100, 200 and 400 ppm.     

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.     

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.     

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).     

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.     

Development of chemically interesterified healthy coconut oil blends

Edible vegetable oil blends, such as coconut:linseed; coconut:safflower; coconut:sunflower; coconut:rice‐bran oils; in the ratio of 70:30 and 60:40 v/v and pure coconut oil (CNO) were interesterified using sodium methoxide 0.5% and subsequently refined to prepare nutritionally superior flowable CNO blends which remained liquid even at sub‐zero temperatures. The slip melting point of chemically interesterified fats could not be determined as they are liquified just after removing from freezing chamber in comparison with the slip melting point of 21.5–26.5 °C for their uninteresterified counterparts. These interesterified fats were liquid and flowable at 6 °C for more than 4 h in a cooling chamber and their solidification temperature ranged between ?2.0 and ?5.5 °C. Free fatty acids showed an increasing trend from 0.35% to 2.0% resulting in decrease in triglycerides After refining these oil blends showed values similar to their controls. However, iodine value of interesterified and uninteresterified oils were close to each other. Differential scanning calorimetry showed the onset of crystallisation at lower temperatures and lower solid fat content for interesterified fats. A nutritionally superior combination of CNO blend which is flowable at low temperature could be prepared.     

<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.     

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.     

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。     

Chemical interesterification of milkfat and milkfat-corn oil blends

Blending and chemical interesterification of fats have been used to modify physical and chemical properties of natural fats. The objective of this study was to produce binary mixtures of butterfat and corn oil that serve as a base for a tablespread, keeping the desirable organoleptic qualities of butter, yet with higher contents of ω-6 fatty acids. Chemical interesterification was performed to improve butter’s physical properties, such as better spreadability. Liquefied butterfat and corn oil were mixed in different proportions and then chemically interesterified. Butterfat consisted of 66.5% saturated fatty acids, with palmitic acid being predominant. Corn oil had more than 50% of linoleic acid in its composition. Interesterification significantly reduced trisaturated and triunsaturated triacylglycerol contents and increased softening points in all blends. The negative coefficients of the blends from multiple regression of the solid fat content revealed a monotectic interaction between butterfat and corn oil in temperatures ranging from 10 to 35 °C, before and after interesterification.     

Thermal and crystal characteristics of enzymatically interesterified fats of fatty acid-balanced oil and fully hydrogenated soybean oil in supercritical CO2 system

Blends of fatty acid-balanced oil that was prepared by the aqueous enzymatic extraction, and with fully hydrogenated soybean oil in different weight ratios from 30:70 to 80:20 (wt%) were interesterified using Lipozyme RM IM in a supercritical CO₂ system. The optimal immobilized enzyme dosage, pressure, substrate ratio, temperature, and time were 6% (w/w) of initial substrates, 8 MPa, blend ratio with 60:40 (wt%) of fatty acid-balanced oil and fully hydrogenated soybean oil, a temperature of 70°C, and reaction time of 2 h, respectively. It was observed that at the optimal conditions, under supercritical CO₂ conditions, the reaction time of the interesterification was shorter than that of conventional enzymatic interesterification. The slip melting point, solid fat content, fatty acid composition, differential scanning calorimetry, polymorphic form and crystal morphology of the enzymatically interesterified fats were evaluated. The results indicated that the interesterified fats showed desirable physical properties with lower slip melting point and solid fat content, suitable crystal form (β′ polymorph), and without trans-fatty acid for possible use as a shortening and margarine stock.     

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     

Zero trans fats from soybean oil and fully hydrogenated soybean oil: Physico-chemical properties and food applications

Blends of soybean oil (SO) and fully hydrogenated soybean oil (FHSBO), with 10%, 20%, 30%, 40% and 50% FHSBO (w/w) content were interesterified under the following conditions: 0.4% sodium methoxide, 500 rpm stirring, 100 °C, 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 monounsaturated and diunsaturated triacylglycerols, resulting in lowering of respective melting points. The interesterified blends displayed reduced SFC at all temperatures and more linear melting profiles as compared with the original blends. Yield values showed increased plasticity in the blends after the reaction. Isosolid diagrams before and after the reaction showed no eutectic interactions. The 90:10, 80:20, 70:30 and 60:40 interesterified SO:FHSBO blends displayed characteristics suited to application, respectively, as liquid shortening, table margarine, baking/confectionery fat and all-purpose shortenings/biscuit-filling base.     

Evaluation of pork backfat firmness and lard consistency using several different physicochemical methods

A total of 96 pigs were fed on a control diet (barley, wheat, soybean meal) or the control diet supplemented with one of six fats, differing in saturated (SFA), cis‐ and trans‐monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) content, in order to produce backfat widely differing in fatty acid composition. In addition to fatty acid composition, firmness was measured, by means of a puncture test, in the intact outer backfat layer and in lard extracted from the outer layer. Melting behaviour and solid fat content (SFC) were determined by differential scanning calorimetry and crystallisation time with a Rapid Interesterification Control‐Box. Regression analyses revealed that all consistency traits were mainly dependant on SFA content, particularly stearic acid. Cis‐MUFA were the next most decisive for crystallisation time and SFC. The prediction of firmness and SFC at 0 °C was improved when the proportion of PUFA was also considered. The stearic to linoleic acid ratio provided the best prediction of lard firmness. It was concluded that MUFA and PUFA exert specific effects on the different consistency characteristics and not only PUFA but also MUFA should be considered in feeding recommendations for growing‐finishing pigs when lard consistency is to be improved. Copyright © 2004 Society of Chemical Industry