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.     

Physical properties of palm kernel olein-anhydrous milk fat mixtures transesterified using mycelium-bound lipase from Rhizomucor miehei

The transesterification activity of mycelium-bound lipase from Rhizomucor miehei on palm kernel olein:anhydrous milk fat (PKO:AMF) blends was investigated. Commercial immobilised R. miehei lipase preparation, Lipozyme IM60 (Novo Nordisk), was used as a comparison. Mixtures of PKO:AMF, at ratios of 100:0, 70:30, 60:40, 50:50 and 0:100, were transesterified using either enzyme in a solvent-free system. The triglyceride (TG) profile, slip melting point, solid fat content, melting thermogram and the polymorphic form of the unreacted and transesterified mixtures were evaluated. Results indicated that transesterification by either enzyme was able to produce an oil mixture with new TG profiles, generally lower slip melting points and solid fat contents. The melting thermograms from differential scanning calorimetry analysis indicated changes in the triglyceride's crystalline composition and an overall shift to lower melting TG. Although the catalytic activities were similar for both lipases, Lipozyme-catalysed mixtures produced higher degrees of transesterification (43–51%) than mycelium-bound lipase-catalysed (22–34%) mixtures. This study also demonstrated that the transesterified PKO:AMF mixture at 70:30 ratio completely melted at 25C, and this meets the melting criteria for fat used in ice cream formulation.     

<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.     

COMPARISON OF TRANSESTERIFIED PALM STEARIN/SUNFLOWER OIL BLENDS CATALYZED BY PSEUDOMONAS AND MUCOR JAVANICUS LIPASE

Palm stearin and sunflower oil mixtures in three different ratio of 3:7, 5:5 and 7:3 (w/w) were subjected to transesterification catalyzed by immobilized lipases from Pseudomonas and Mucor javanicus in a solvent-free system. The ability of these lipases to alter the physical properties of the fat blends was studied. Slip melting point (SMP), differential scanning calorimetry and X-ray diffraction analyses were used to evaluate the physical properties of the transesterified blends. The percentage of free fatty acids liberated was also determined. Results indicated that the Pseudomonas lipase was catalytically more active than Mucor javanicus lipase as shown by marked changes in the triacylglycerol profile and fatty acids released. Pseudomonas lipase-catalyzed mixtures also showed a bigger drop in SMP and successfully changed the polymorphic form from the dominant β crystal form in control blends to β'crystal form in the transesterified mixtures.     

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.     

OXIDATIVE STABILITY OF A LIPASE-CATALYZED TRANSESTERIFIED PALM STEARIN AND PALM KERNEL OLEIN BLEND

A palm stearin (PS) and palm kernel olein (PKO) blend at ratio 1:1 (by weight) was enzymatically transesterified. The oxidative stability of the blend, its control (without transesterification) as well as the PS and PKO were evaluated in a conventional oven at 60C for two weeks. Samples were withdrawn at 2 day intervals and analyzed for their peroxide value, iodine value, content of conjugated diene and fatty acid (FA) composition. The transesterified blend was found to be more susceptible than the control to oxidation during storage. PS exhibited the largest change in oxidative parameters employed, mainly due to its high level of unsaturated FA.     

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.     

Enzymatic and Chemical Interesterification of Rice Bran Oil,Sheaolein, and Palm Stearin and Comparative Study of Their Physicochemical Properties

Abstract: Total of 3 different mixtures of rice bran oil (RBO), sheaolein (SO), and palm stearin (PS) (RBO : SO : PS, 40 : 35 : 25; 15 : 40 : 45; 10 : 35 : 55) were modified by enzymatic interesterification (EIE) using TLIM as a bio‐catalyst. After interesterification, a physicochemical properties of selected ratio (10 : 35 : 55; RBO : SO : PS) was compared with chemical interesterification (CIE). CIE sample showed higher SFC than EIE in each measured temperature. DAG content was lower in CIE than EIE sample. Besides, each EIE or CIE products were compared with blends, where higher SFC, longer induction time was observed in the blends. Oxidative stability was measured based on Rancimat and peroxide value (PV) where EIE sample showed longer induction time and lower PV compared to CIE sample. Further, EIE sample was selected for oxidation studies and kept at 60 °C for 22 d after the addition of antioxidants (EGCG, rosemary) where induction time was significantly increased compared to control. EGCG containing sample showed longer induction time and lower PV compared to rosemary containing sample. Practical Application: This research can show the application of SO in the bakery industry, which is a byproduct of shea butter production. There is very limited published information about SO application in bakery food. In addition, it could be useful for industrial application to compare the physicochemical properties of enzymatic interesterification compared to chemical interesterification.     

Flow properties of table margarine prepared from lipase-catalysed transesterified palm stearin:palm kernel olein feedstock

The flow properties of an experimental table margarine prepared from Rhizomucor miehei lipase-catalysed transesterified palm stearin:palm kernel olein (PS:PKO) blend at 40:60 was stored for 3 months at test temperatures of 20 and 30°C and determined using a controlled-rate rheometer. A commercial table margarine was used as a comparison. The shear stress-shear rate data was represented well by the Herschel–Bulkley model (r > 0.99). The mean yield stress values during storage were the highest for the experimental table margarine. However, the effect of storage on the mean yield stress was insignificant (p > 0.001). The Power Law model with a yield stress also represented the margarine flow well (r > 0.99) and the Power Law intercepts and slopes were also the highest for the experimental margarines, indicating a higher degree of firmness in the experimental samples. Storage effect was also insignificant (p > 0.05).     

Interpretation of triacylglycerol profiles of palm oil,palm kernel oil and their binary blends

The effects of lipase-catalyzed interesterification (IE) on changes in the chemical composition of palm oil (PO), palm kernel oil (PKO) and their binary blends at 3:1, 1:1 and 1:3 (w/w) ratios, using both 1,3 specific Rhizomucor miehei, (Lipozyme™) and non-specific Pseudomonas sp. lipases were evaluated. IE of the native PO and PKO showed very distinct chemical composition changes. Catalysis of PO, using both lipases, caused synthesis of more medium and long chain triacylglycerols (TAG), with MMM/OLL, MMP, OOO and PPP (M, myristic acid; O, oleic acid; L, linoleic acid; P, palmitic acid) increasing in concentration. In contrast, IE of PKO resulted in the formation of more short and medium chain TAG, with LaLaO and LaMO (La, lauric acid; C, capric acid) experiencing noteworthy increments. Both Rhizomucor miehei and Pseudomonas sp. lipases showed high affinity in hydrolyzing PO fatty acids, resulting in high TAG losses and formation of high percentages of partial glycerides while these lipases were found to enhance the synthesis process in IE of PKO. Catalysis of the three binary blends caused similar TAG compositional changes where the synthesis process focussed on the medium chain TAG, while hydrolysis was observed in the short and long chain TAG that showed corresponding decreases. Catalysis of the three blends was influenced by the major fraction of these blends. Among these blends, PO: PKO at a 1:1 ratio exhibited the highest degree of IE. The diversity and quantity of available TAG are postulated to be the main causes of the different catalytic activities in these binary blends with Pseudomonas sp. lipase showing a higher degree and rate of IE than R. miehei.     

Application of differential scanning calorimetry (DSC), HPLC and pNMR for interpretation primary crystallisation caused by combined low and high melting TAGs

The main goal of the present work was to assess the mechanism of crystallisation, more precisely the dominant component responsible for primary crystal formations and fat agglomerations. Therefore, DSC results exhibited significant effect on temperature transition; peak sharpness and enthalpy at palm stearin (PS) levels more than 40 wt.%. HPLC data demonstrated slight reduction in the content of POO/OPO at PS levels less than 40 wt.%, while the excessive addition of PS more than 40 wt.% increased significantly PPO/POP content. The pNMR results showed significant drop in SFC for blends containing PS less than 40 wt.%, resulting in low SFC less than 15% at body temperature (37 °C). Moreover, the values of viscosity (η) and shear stress (τ) at PS levels over 40 wt.% expressed excellent internal friction of the admixtures. All the data reported indicate that PPO/POP was the major component of primary nucleus developed. In part, the levels of PS should be less than 40 wt.%, if these blends are designed to be used for margarine production.     

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.     

VISCOELASTIC PROPERTIES OF TABLE MARGARINE PREPARED FROM LIPASE-CATALYZED TRANSESTERIFIED MIXTURES OF PALM STEARIN AND PALM KERNEL OLEIN

A controlled-stress rheometer was used to evaluate dynamic viscoelastic (VE) performance of an experimental table margarine prepared from a transesterified palm stearin (PS):palm kernel olein (PKO) mixture (40:60 ratio) using Rhizomucor miehei lipase as the biocatalyst. Comparison was made using a commercial table margarine made of palm oil and palm kernel oil. The experiments were carried out over a period of three months with the margarines kept at 20 and     

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.     

Physicochemical properties and crystallisation behaviour of bakery shortening produced from stearin fraction of palm-based diacyglycerol blended with various vegetable oils

The stearin fraction of palm-based diacylglycerol (PDAGS) was produced from dry fractionation of palm-based diacylglycerol (PDAG). Bakery shortening blends were produced by mixing PDAGS with either palm mid fraction, PMF (PDAGS/PMF), palm olein, POL(PDAGS/POL) or sunflower oil, SFO (PDAGS/SFO) at PDAGS molar fraction of X_PDAGS = 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%. The physicochemical results obtained indicated that C16:0 and C18:1 were the dominant fatty acids for PDAGS/PMF and PDAGS/POL, while C18:1 and C18:2 were dominant in the PDAGS/SFO mixtures. SMP and SFC of the PDAGS were reduced with the addition of PMF, POL and SFO. Binary mixtures of PDAGS/PMF had better structural compatibility and full miscibility with each other. PDAGS/PMF and PDAGS/SFO crystallised in β′+β polymorphs in the presence of 0.4–0.5% PDAGS while PDAGS/POL resulted in β polymorphs crystal. The results gave indication that PDAGS: PMF at 50%:50% and 60%:40% (w/w) were the most suitable fat blend to be used as bakery shortening.     

Effects of organic solvents on transesterification of phospholipids using phospholipase A2 and lipase

The transesterification abilities of phospholipase A₂ and Mucor javanicus lipase in various organic solvents were studied. Phosphatidylcholine and caprylic acid (molar ratio, 1:6) were transesterified by incubation at 40°C in three organic solvents using phospholipase A₂ and M. javanicus lipase. The fatty acid composition of the reaction product was measured using gas chromatography. Caprylic acid was incorporated into the sn-1 and -2 positions at a rate of 87.7% using phospholipase A₂ in hexane, and 36.7% using M. javanicus lipase in diethyl ether. Higher acyl migration into sn-2 was observed in diethyl ether than in hexane during transesterification using M. javanicus lipase, however, there was no substantial difference in the caprylic acid content at the sn-2 position. Acyl migration during transesterification in methanol was lower than in other organic solvents. Non-polar hexane and diethyl ether were more effective for transesterification than methanol.     

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.     

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.     

Oxidation and antioxidative effects of rosemary extract and catechin on enzymatically modified lipids containing different total and positional fatty acid compositions

The oxidative stabilities of enzymatic modified lipids (EMLs) were studied using pine nut oil (PN) and palm stearin (PS) as substrates (w/w, 40:60; 30:70) vs. a physical blend (PB). The amount of pinolenic acid (PLA) at the sn-2 position in EML was increased to 5.5% compared to 0.8% in PB. The acid, peroxide, p-anisidine, and TBARS values were used to measure the oxidative stability of EML and PB. After 30 days of oxidation, only 1.5 and 0.7% of total PLA at sn-2 position PLA were detected in EML of PN:PS 40:60 and PN:PS 40:60, respectively. EMLs were more vulnerable to oxidization than PB. Different concentrations of rosemary (1,000 and 2,000 mg/kg) and catetchin (400 and 800 mg/kg) were added to EMLs to reduce the oxidation level. Results indicated that these two antioxidants deterred the extent of oxidation in EMLs.     

Performance of a lipase-catalyzed transesterified palm kernel olein and palm stearin blend in frying banana chips

The frying performance of an enzymatically transesterified palm stearin and palm kernel olein (1:1 by weight) blend was compared with its control (physical mixture or no enzyme added) and a commercial plastic frying shortening (CS). The samples were used as deep-fat frying media at 180°C for banana chips for seven consecutive days. The samples were then analysed for iodine value (IV), free fatty acid (FFA) content, peroxide value (PV), thiobarbituric acid (TBA) value, p-anisidine value (AV), total polar compounds (TPC), fatty acid composition, specific extinction, E^1%_1cm at 233 and 269 nm, polymer contents, viscosity and colour indices. The fried banana chips were analysed for acceptability by sensory evaluations. Storage properties of the banana chips were also evaluated by trained sensory panellists and a modified TBA test. The transesterified blend was found to have significantly (P<0.05) higher IV, FFA, PV, TBA value, AV, TPC, E^1%_1cm at 233 and 269 nm values, polymer content, viscosity and colour indices compared to the control, indicating that the transesterified blend was more susceptible to oxidative deterioration during deep-fat frying. CS generally showed the largest changes in most of the parameters, basically due to its high polyunsaturated fatty acid levels. There was no significant difference (P>0.05; for all the attributes tested) between the acceptability of the banana chips fried by the transesterified and control blends. However, the banana chips fried in CS had significantly (P<0.05) lower scores in terms of flavour, aftertaste and overall acceptability. This might be due to the typical hydrogenation flavour of CS. In the storage stability study of the banana chips, it was found that the banana chips fried in the transesterified blend were significantly (P<0.05) more rancid (lower score in sensory evaluations) and had a higher TBA value at the end of the storage time than the control.