Effect of Saturated/Unsaturated Fatty Acid Ratio on Physicochemical Properties of Palm Olein–Olive Oil Blend

Although blending polyunsaturated oil with more saturated or monounsaturated oils has been studied extensively, there is no similar information regarding the partial replacement of palm olein with olive oil (OO). Therefore the main objective of this study was to investigate the effects of OO partial replacement (0, 25, 50, 75, 90 and 100% w/w) on the chemical stability of palm olein oil (POO). The physicochemical properties of oil samples namely iodine value, peroxide value (PV), anisidine value, TOTOX value (total oxidation value, TV), free fatty acid (FFA), cloud point, color and viscosity were considered as response variables. Significant differences among the oil blend properties were determined at the significance level of P < 0.05. Apart from FFA, all the response variables were significantly influenced by type and concentration of oils. The oil blend containing 10% POO and 90% OO showed the highest TV (6.10); whereas the blend containing 90% POO and 10% OO exhibited the least TV (2.41). This study indicated that the chemical stability of oil blend significantly (P < 0.05) increased with increasing the proportion of polyunsaturated/monounsaturated fatty acid.     

Palm Olein and Olive Oil Cause a Higher Increase in Postprandial Lipemia Compared with Lard but Had No Effect on Plasma Glucose,Insulin and Adipocytokines

Postprandial lipemia impairs insulin sensitivity and triggers the pro-inflammatory state which may lead to the progression of cardiovascular diseases. A randomized, crossover single-blind study (n = 10 healthy men) was designed to compare the effects of a high-fat load (50 g fat), rich in palmitic acid from both plant (palm olein) or animal source (lard) versus an oleic acid-rich fat (virgin olive oil) on lipemia, plasma glucose, insulin and adipocytokines. Serum triacylglycerol (TAG) concentrations were significantly lower after the lard meal than after the olive oil and palm olein meals (meal effect P = 0.003; time effect P < 0.001). The greater reduction in the plasma non-esterified free fatty acids levels in the lard group compared to the olive oil meal was mirrored by the changes observed for serum TAG levels (P < 0.05). The magnitude of response for plasma glucose, insulin and adipocytokines [interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and leptin] were not altered by the type of dietary fats. A significant difference in plasma IL-1β was found over time following the three high fat loads (time effect P = 0.036). The physical characteristics and changes in TAG structure of lard may contribute to the smaller increase in postprandial lipemia compared with palm olein. A high fat load but not the type of fats influences concentrations of plasma IL-1β over time but had no effect on other pro-inflammatory markers tested in the postprandial state.     

Comparative analysis of triacylglycerols from Olea europaea L. fruits using HPLC and MALDI‐TOFMS

MALDI‐TOFMS and HPLC are two analytical methods that were used to characterize triacylglycerols (TAG) of the Meski, Sayali, and Picholine Tunisian olive varieties. The HPLC chromatograms of the oils showed the presence of 15 TAG species, among which triolein (OOO) was the most abundant (21–48%). In the Sayali cultivar, OOO was the predominant TAG species followed by POO and LOO. However, the minor TAG molecules were represented by LnLO and LnLP. MALDI mass spectra produced sodiated ([M + Na]⁺) and potassiated ([M + K]⁺) TAG molecules; only the major TAG were potassiated [OOO + K] ([OOO + K]⁺, [POO + K]⁺, and [LOO + K]⁺). In contrast to the HPLC chromatograms, the MALDI mass spectra showed 13 peaks of TAG. The major peak was detected at m/z 907, which corresponds to OOO with an Na⁺ adduct. The results from both HPLC and MALDI techniques predict the fatty acid composition and their percentages for each olive variety. Practical applications: TAG are the main components in vegetable oils. These biomolecules determine the physical, chemical, and nutritional properties of the oils. The nutritional benefits of TAG are related to DAG (moderate plasma lipid level) and esterified FA, which are intermediate biosynthetic molecules of TAG. TAG analysis is necessary to discriminate between oils of different origin, since some oils have similar FA profiles. Olive products, oils, and table olives, are the main diet sources of TAG in the Mediterranean countries. In this work, chromatographic and spectrometric methods were used for TAG analysis and characterization of Tunisian olive varieties.     

Classification of Turkish Monocultivar (Ayvalık and Memecik cv.) Virgin Olive Oils from North and South Zones of Aegean Region Based on Their Triacyglycerol Profiles

In this study, a total of 22 domestic monocultivar (Ayval?k and Memecik cv.) virgin olive oil samples taken from various locations of the Aegean region, the main olive growing zone of Turkey, during two (2001–2002) crop years were classified and characterized by well‐known chemometric methods (principal component analysis [PCA] and hierarchical cluster analysis [HCA]) on the basis of their triacylglycerol (TAG) components. The analyses of TAG components (LLL and major fractions LOO, OOO, POO, PLO, SOO, and ECN 42–ECN 50) in the oil samples were carried out according to the HPLC method described in a European Union Commission (EUC) regulation. In all analyzed samples the value of trilinolein (LLL), the least abundant TAG, did not exceed the maximum limit of 0.5 % given by the EUC regulation for different olive oil grades. The ranges of abundant TAG, namely LOO, OOO, POO, PLO, and SOO, were 13.30–16.08, 37.27–46.36, 21.39–23.24, 4.93–7.03, and 4.72–6.00 %. The TAG data of Aegean virgin olive oils were similar to those of products from important olive‐oil‐producing Mediterranean countries was determined. Also, the estimation of major fatty acids (FA) was carried out by using a formula based on TAG data. The PCA results showed that some TAG components have an important role in the characterization and geographical classification of 22 monocultivar virgin olive oil. The Aegean virgin olive oil samples were successfully classified and discriminated into two main groups as the North and South (growing) subzones or Ayval?k and Memecik olives (cultivars) according to the HCA results based on experimental TAG data and calculated major FA profile.     

Frying Quality Characteristics of French Fries Prepared in Refined Olive Oil and Palm Olein

The objective of this study was to compare two oils with different polyunsaturated/saturated (P/S) fatty acid ratios, refined olive oil (P/S 0.75) and palm olein (P/S 0.25), in frying French fries. The chemical qualities of the oil residues extracted from the French fries were assayed for five consecutive batches fried at 1-h intervals. The levels of total polar compounds, free fatty acids, p-anisidine value and phytosterol oxidation products (POPs) were elevated in French fries fried in both oils. The level of total polar compounds increased from 4.6 in fresh refined olive oil to 7.3% in final batches of French fries. The corresponding figures for palm olein were 9.8–13.8%. The level of free fatty acid in fresh refined olive oil increased from 0.06 to 0.11% in final products. These figures for palm olein were 0.04–0.13%. The p-anisidine value increased from 3.7 to 32.8 and 2.5 to 53.4 in fresh oils and in final batches of French fries in refined olive oil and palm olein, respectively. The total amount of POPs in fresh refined olive oil increased from 5.1 to 9.6 μg/g oil in final products. These figures were 1.9 to 5.3 μg/g oil for palm olein.     

Formulation and Characterization of Human Milk Fat Substitutes Made from Blends of Refined Palm Olein,and Soybean,Olive, Fish,and Virgin Coconut Oils

The simplest and the most cost-effective way of human milk fat substitute (HMFS) production is formulating of suitable vegetable oils at proper ratios. To do this, the D-optimal mixture design was used to optimize the HMFS formulation. The design included 25 formulations made from refined palm olein (35–55%), soybean oil (5–25%), olive oil (5–20%), virgin coconut oil (5–15%), and fish oil (0–10%). Samples were produced in laboratory and characterized in terms of fatty acid and triacylglycerol (TAG) compositions, free fatty acid content, peroxide value, iodine value, and oxidative stability index (OSI). HMFS samples were also compared with Codex Alimentarius (CA) and Iran National Standards Organization (INSO) standards. Each characteristic of HMFS samples was then expressed as a function of ingredient ratio using regression models. Finally, using numerical optimization, four optimized blends (PB₁-PB₄) were selected, made in the laboratory (HMFS₁-HMFS₄), characterized, and compared with CA and INSO standards. The properties of all the optimized blends (except the palmitic acid content of HMFS₂ and the monounsaturated fatty acid [MUFA] content of HMFS₃) met the standards. HMFS₄ showed the highest OSI in Rancimat and the lowest oxidation rate in Schaal oven tests. POL (19.53–21.73%), PPO (20.77–21.73%), OOO (9.11–11.16%), and OPO (8.84–9.46%) were the main (totally about 60%) TAG species found in HMFS samples. In conclusion, the HMFS₄ formula (55% palm olein, 13.5% soybean oil, 16% refined olive oil, 15% virgin coconut oil, and 0.5% fish oil) was suggested as the best formula for HMFS production.     

Synthesis of the structured lipid 1,3-dioleoyl-2-palmitoylglycerol from palm oil

Human milk fat contains 20–25% palmitic acid (16∶0) and 30–35% oleic acid (18∶1). More than 60% of the plamitic acid occurs at the sn-2 position of the glycerol backbone. Palm oil is a rich source of both palmitic and oleic acids. The structured lipid 1,3-dioleyl-2-palmitoylglycerol (OPO) is an important ingredient in infant formula. OPO was synthesized from palm oil by a three-step method. In the first step, low-temperature fractionation was applied to palm oil FA, yielding a palmitic acid-rich fraction (87.8%) and an oleic acid-rich fraction (96%). The palmitic acid content was further increased to 98.3% by transforming palmitic acid into ethyl palmitate. In the second step, esterification of ethyl palmitate and glycerol catalyzed by lipase Novozym 435 under vacuum (40 mm Hg) was employed for the synthesis of tripalmitin. Finally, OPO was obtained by the reaction of tripalmitin. Finally, OPO was obtained by the reaction of tripalmitin with oleic acid catalyzed by Lipase IM 60. In this final step, the TAG content in the product acylglycerol mixture was 97%, and 66.1% oleic acid was incorporated into TAG. Analysis of the FA composition at the sn-2 position of TAG showed 90.7 mol% of palmitic acid and 9.3 mol% of oleic acid. OPO content in the product TAG was ca. 74 mol%. Thus, an efficient method was developed for the synthesis of OPO from palm oil.     

Effect of Lipase Activity and Specificity on the DAG Content of Olive Oil from the Shodoshima-Produced Olive Fruits

Olive oils have a higher relative diacylglycerol (DAG) content than other plant oils. The lipase in olive fruits is involved in DAG production and is directly related to the acidity of the olive oil. However, the lipase activity and positional selectivity have not been clarified. To investigate the properties of olive fruit lipase, olive fruits of the Mission variety harvested during mid-December of 2005 on Shodoshima Island (Japan) were stored at 20, 30 or 40 °C for 4 weeks. Changes in the acidity and acylglycerol content of the oils extracted from the stored fruits were analyzed. The acidity and DAG content of the olive oils increased due to triacylglycerol (TAG) hydrolysis during storage. sn-1,2-DAGs preferentially increased during the early stages of storage, indicating that the olive fruit lipase is enantioselective for the sn-3 position, while non-enzymatic isomerization of sn-1,2-DAGs was observed throughout the entire duration of storage. Kinetic analysis revealed that the enantioselectivity of olive fruit lipase for the sn-3 position was approximately four times greater than for the sn-1 position. The lipase was gradually inactivated at temperatures of 30 °C or higher, and the ratios of the rate constant for inactivation to TAG hydrolysis at the sn-3 position was 0.2, 13, and 23 at 20, 30, and 40 °C, respectively.     

Frying Stability of Canola Oil Blended with Palm Olein, Olive, and Corn Oils

The fatty acid composition, peroxide value (PV), acid value (AV), iodine value (IV), total tocopherols (TT) content, and total phenolics (TP) content of canola oil (CAO), palm olein oil (POO), olive oil (OLO), corn oil (COO), and the binary and ternary blends of the CAO with the POO, OLO, and COO were determined. The blends were prepared in the volume ratios of 75:25 (CAO/POO, CAO/OLO, CAO/COO) and 75:15:10 (CAO/POO/OLO, CAO/POO/COO). The CAO and its blends were used to fry potato pieces (7.0 × 0.5 × 0.3 cm) at 180 °C. During the frying process, the total polar compounds (TPC) content, AV, oil/oxidative stability index (OSI), and color index (CI) of the CAO/blends were measured. In general, frying stability of the CAO was significantly (P < 0.05) improved by the blending, and the frying performance of the ternary blends was found to be better than that of the binary blends.     

Enzymatic Interesterification of Palm Oil and Fractions: Monitoring the Degree of Interesterification using Different Methods

Interesterification is an important modification technique for fats and oils resulting in the redistribution of the fatty acids among the glycerol backbone and thus changing the physico-chemical properties of the modified fat. In this study palm oil, palm olein and soft palm mid fraction (PMF) were subjected to both enzymatic (batchwise) and chemical interesterification. The reaction products were characterized before, during and after interesterification by HPLC, pulsed NMR (p-NMR) and differential scanning calorimetry (DSC). Interesterification led to more uniform triacylglycerol (TAG) compositions with smaller differences in final physico-chemical properties between the studied substrates. The degree of interesterification was evaluated on the basis of TAG composition and solid fat content (SFC). Significant differences between both methods were observed. The degree of interesterification based on SFC is therefore a better tool to evaluate the rate constant of the reaction as the TAG composition method does not take into consideration the formation of positional isomers at the end of the enzymatic process.     

Regiospecific determination of short-chain triacylglycerols in butterfat by normal-phase HPLC with on-line electrospray-tandem mass spectrometry

This study uses normal-phase HPLC with on-line positive ion electrospray mass spectrometry (ESI-MS) to obtain quantitative compositional data on both synthetic and butterfat short-chain TAG. The product ion tandem MS of standards averaged 11.1 times lower in abundance of the ion formed by cleavage of FA from the sn-2-position for the pairs of regioisomers in the TAG classes: L/L/S-L/S/L and L/S/S-S/L/S, where L denotes long and S short acyl chain (C₂−C₆). The molar correction factors, determined for 42 regioisomeric pairs of short-chain TAG of 20 randomized mixture of standards, differed by 1.4–80% as the ratios varied between 0.217 and 5.847. Butterfat TAG were resolved into four fractions on short flash chromatography grade silica gel columns. Pairs of regioisomers in the TAG classes L/S/S-S/L/S with predominance of L/S/S isomers and the sole regioisomers in the TAG classes L/L(M)/S were identified by tandem MS, where M denotes either 8∶0 or 10∶0 acyl chain. The total proportion of L/L(M)/S isomers was estimated at 34.7 and that of L/S/S-S/L/S at 1.0 mol%, including a small proportion of S/S/S. In contrast to previous work, the present data indicate the presence of a small proportion of butyric and caproic acids in the sn-1-position. The overall distribution of the FA in the short-chain TAG of butterfat, calculated from direct MS measurements, was consistent with the results of indirect determinations based on stereospecific analyses of total butterfat.     

An Interesterified Palm Olein Test Meal Decreases Early-Phase Postprandial Lipemia Compared to Palm Olein: a Randomized Controlled Trial

Palm oil that has been interesterified to produce a higher proportion of palmitic acid (16:0) in the sn‐2 position reduces postprandial lipemia in young, normolipidemic men and women, but effects in older subjects with higher fasting triacylglycerol (TAG) concentrations are unknown. We tested the hypothesis that high‐fat meals rich in interesterified palm olein (IPO) decrease lipemia and alter plasma lipoprotein fraction composition compared to native palm olein (NPO) in men aged 40–70 years with fasting TAG concentrations ≥1.2 mmol/L. Postprandial changes in plasma lipids following meals containing 75 g fat (NPO and IPO) were compared using a randomized, double‐blind crossover design (n = 11). Although there were no significant differences in plasma TAG concentrations between meals over the total 6‐h postprandial measurement period, IPO resulted in a decreased plasma TAG response during the first 4 h of the postprandial period (iAUC 1.65 mmol/L h, 95 % CI 1.01–2.29) compared to NPO (iAUC 2.33 mmol/L h, 95 % CI 1.58–3.07); meal effect P = 0.024. Chylomicron fraction TAG concentrations at 4–6 h were slightly reduced following IPO compared to NPO [NPO?IPO mean difference 0.29 mmol/L (95 % CI ?0.01–0.59), P = 0.055]. There were no differences in IDL fraction TAG, cholesterol or apolipoprotein B48 concentrations following IPO compared with NPO. In conclusion, consuming a meal containing palm olein with a higher proportion of 16:0 in the sn‐2 position decreases postprandial lipemia compared to native palm olein during the early phase of the postprandial period in men with higher than optimal fasting triacylglycerol concentrations.     

Effects of α-Tocopherol on Oxidative Stability and Phytosterol Oxidation During Heating in Some Regular and High-Oleic Vegetable Oils

The first part of this study evaluated oxidative stability in high-oleic rapeseed oil, palm olein, refined olive oil, low erucic acid rapeseed oil and sunflower oil. The results showed oxidative stability in the order: palm olein > high-oleic rapeseed oil > refined olive oil > low erucic acid rapeseed oil > sunflower oil, as determined by the Rancimat method. Addition of α-tocopherol at high levels of up to 0.2% increased the oxidative stability of refined olive oil, whereas the opposite effect was generally observed in the other oil samples. In the second part of the study, high-oleic rapeseed oil, palm olein, refined olive oil and refined olive oil containing 0.2% α-tocopherol were heated for 3, 6, 9 and 12 h at 180 °C. The peroxide and p-anisidine values generally increased over time in the samples, including olive oil containing 0.2% α-tocopherol. High-oleic rapeseed oil contained the highest amount of total sterols and total phytosterol oxidation products (POPs), but during heating the total POPs content increased moderately (~10%), in contrast to the threefold increase after 12 h of heating in palm olein and refined olive oil. Very high levels of 6-hydroxy derivatives of brassicastanol, campestanol and sitostanol and of 7-ketobrassicasterol were observed in high-oleic rapeseed oil samples. Addition of 0.2% α-tocopherol during heating significantly decreased POPs formation in refined olive oil (P < 0.05).     

Optimized interesterification of virgin olive oil with a fully hydrogenated fat in a batch reactor: Effect of mass transfer limitations

The lipase‐catalyzed interesterification of virgin olive oil and fully hydrogenated palm oil (FHPO) was studied in a batch reactor operating at 75 °C. The reactions between olive oil {rich in OOO (32.36%), OPO (21.7%) and OLO (11.6%) [L = linoleic; O = oleic; P = palmitic acid]} and the fully hydrogenated fat {(36.5% PSP, 28.8% PPP, 23.2% SPS) [S = stearic acid]} produced semi‐solid fats. For an initial weight ratio of olive oil to FHPO of 60 : 40, the reaction product is a complex mixture of triacylglycerol (TAG) species. The TAG profile of the fat product is time dependent. Because of the high viscosity of the liquid reagent phase, it was important to determine if mass transfer effects were significant. Hence, the reaction was optimized with respect to the type and speed of agitation employed, temperature, use of solvent, and the type of biocatalyst. Three immobilized lipases [from Thermomyces lanuginosus (TL IM), Rhizomucor miehei (RM IM) and Candida antarctica B (Novozym 435)] were compared as catalysts for the interesterification reaction. Equilibrium is reached four times faster (in 1–4 h) with a magnetic stirrer to provide agitation than when agitation is not sufficient, i.e. when orbital agitation is employed. Equilibrium was reached faster with Lipozyme TL IM than with the other two lipases. The effects of all the factors investigated on the composition of the products have also been determined. Semi‐solid fats obtained with the non‐specific Novozym 435 contain levels of unsaturated fatty acid residues on sn‐2 sites that are similar to the products obtained with the 1(3)‐regiospecific enzymes Lipozyme TL IM and RM IM. The chemical properties of the product semi‐solid fat were characterized. The fat prepared using optimal reaction conditions contained 17.20% OPO, 13.61% OOO, 11.09% POP, and 10.35% OSP isomers as the primary products. The induction time obtained in the assay of the oxidative stability of the fat product was 21 h at 98 °C. The lipases Lipozyme TL IM and Novozym 435 were very stable with residual activities of 90 and 100%, respectively, after 15 batch reaction cycles.     

Biochemical Characterization of Arbequina Extra Virgin Olive Oil Produced in Turkey

Varieties of the olive cultivar Arbequina have recently been cultivated in Turkey. The objective of the study is to characterize and evaluate extra‐virgin olive oils (EVOO) produced from Arbequina grown in the Aegean and Mediterranean regions of Turkey. Major and minor components such as carotenoids, squalene, phenolics and tocopherols were studied to assess their effects on product quality and health benefits. The samples, identified as ArbqI and ArbqA, were from the Izmir and Adana provinces, respectively. Samples were analyzed by GC‐FID to determine fatty acid composition, sterol composition, TAG profile and squalene content. Individual phenolic fractions were analyzed by LC–MS/MS and tocopherol isomers were determined by HPLC. According to the results obtained from this study; Total phenolic content (TPC) of the samples were 454.68 and 50.86 mg Gallic acid/kg oil for ArbqI and ArbqA, respectively. Hydroxytyrosol and tyrosol were determined to be the main phenols. The major tocopherol isomer found in ArbqI and ArbqA was α‐tocopherol with levels of 179.55 and 202.5 mg/kg oil, respectively. β‐Carotene levels in both samples were similar at 0.2 mg/kg. Findings of this study were compared with the literature on Arbequina olive oil produced in different countries. It was determined that Arbequina olive oil of high quality can be produced in Turkey, especially in the Aegean region.     

The Role of Oil Phase in the Stability and Physicochemical Properties of Oil-in-Water Emulsions in the Presence of Gum Tragacanth

Different emulsions based on six types of vegetable oils (sunflower, canola, sesame, olive, coconut, and palm olein) were studied to investigate the role of the oil phase in the stability and physicochemical characteristics of oil-in-water emulsions prepared with gum tragacanth. The results indicated that the stability, rheological parameters, and size distribution of emulsions were dependent on the oil type. Based on the interfacial tension value, the type of oil did not have a significant effect on the gum tragacanth-emulsifying properties. The formulation based on sunflower and coconut oil led to producing more stable emulsion and a sample containing palm olein resulted in an unstable emulsion. Rheological analysis revealed that the sample based on palm olein showed the lowest consistency coefficient (2.10 ± 0.05 Pas ⁿ), elastic modulus (3.90 ± 0.21 Pa), and energy of cohesion (80.87 ± 1.1 J m⁻³). This study revealed that using oils with lower viscosity and higher density led to the higher stability of the emulsion samples.     

Nachweis der Glyceride veresterter Olivenöl-Fettsäuren

Detection of the Glycerides of Esterified Olive Oil Fatty Acids Natural olive oil and ester oil with the same fatty acid composition contain approximately the same amount of dipalmito-olein (ca. 4%) and palmito-diolein (ca. 20%). The positional isomers of these glycerides which contain palmitic acid in the 2-position, occur in very small amount in olive oil but are present in considerably larger amount in ester oil. The same is also true for the corresponding stearic acid containing glycerides. The dipalmito-olein and palmito-diolein containing fractions were isolated by silver nitrate chromatography. The characteristic ratios of the positional isomers (POP/PPO and POO/OPO) in both the oils are determined indirectly by enzymatic hydrolysis of the fatty acids in 1,3-position and analysing the 2-monoglyceride fatty acids gas chromatographically.     

Process optimization of simultaneous enzymatic production of 1,3-dioleoyl-2-palmitoylglycerol and 1-oleoyl-2-palmitoyl-3-linoleoylglycerol

1,3-dioleoyl-2-palmitoylglycerol (OPO), a structured triacylglycerols (TAG) containing palmitic acid at sn-2 position, is widely used as breast milk fat substitutes in infant formula. Interestingly, the main component of breast milk fat in Western countries is OPO while Chinese breast milk contains both 1-oleoyl-2-palmitoyl-3-linoleoylglycerol (OPL) and OPO. Thus, OPL is additionally essential for Chinese infants. In the present study, we developed a process for simultaneous production of OPL and OPO. According to the fatty acid (FA) composition of Chinese breast milk, soy oil, palm kernel stearin, and palm stearin were selected as the base oils for random interesterification, and the appropriate ratio was determined as 2:3:15. Then interesterification at sn-1,3 position was conducted, four reaction parameters were examined, where 1.6 molar ratio of oleic acid to linoleic acid (OLA/LNA), 10% enzyme quantity, TAG to FA ratio of 1:8 and reaction temperature of 56°C were ultimately established as the optimal conditions to achieve the target of the present study, and the OPO and OPL contents in the final products were 23.1% and 26.2%, respectively. Finally, molecular distillation was applied to purify above achieved breast milk fat substrates. Higher oil dropping speed, oil temperature, and agitation speed were favorable conditions, and the lowest acid value that achieved in the present study was 3.46 mgKOH/g. Overall, we established an efficient preliminary process for the simultaneous production of OPO and OPL, which could provide an important reference for commercial production of breast milk fat substrates for Chinese infants.     

Application of palm olein in the production of zero‐trans Iranian vanaspati through enzymatic interesterification

The utilization of palm olein in the production of zero‐trans Iranian vanaspati through enzymatic interesterification was studied. Vanaspati fat was made from ternary blends of palm olein (POL), low‐erucic acid rapeseed oil (RSO) and sunflower oil (SFO) through direct interesterification of the blends or by blending interesterified POL with RSO and SFO. The slip melting point (SMP), the solid fat content (SFC) at 10–40 °C, the carbon number (CN) triacylglycerol (TAG) composition, the induction period (IP) of oxidation at 120 °C (IP₁₂₀) and the IP of crystallization at 20 °C of the final products and non‐interesterified blends were evaluated. Results indicated that all the final products had higher SMP, SFC, IP of crystallization and CN 48 TAG (trisaturated TAG), and lower IP₁₂₀, than their non‐interesterified blends. However, SMP, SFC, IP₁₂₀, IP of crystallization and CN 48 TAG were higher for fats prepared by blending interesterified POL with RSO and SFO. A comparison between the SFC at 20–30 °C of the final products and those of a commercial low‐trans Iranian vanaspati showed that the least saturated fatty acid content necessary to achieve a zero‐trans fat suitable for use as Iranian vanaspati was 37.2% for directly interesterified blends and 28.8% for fats prepared by blending interesterified POL with liquid oils.     

Separation of Triacylglycerols from Edible Oil Using a Liquid Chromatography–Mass Spectrometry System with a Porous Graphitic Carbon Column and a Toluene–Isopropanol Gradient Mobile Phase

This study presented a rapid and practical method of separating triacylglycerol (TAG) from edible oil using high‐performance liquid chromatography (LC) coupled with atmospheric‐pressure chemical ionization (APCI)/mass spectrometry (MS) system with a porous graphitic carbon column (150 mm × 2.1 mm, 5 μm) and a toluene–isopropanol–formic acid mobile phase. After investigating the experimental conditions, the gradient toluene–isopropanol mobile phase containing 0.1% formic acid was changed from 50:50 to 80:20 in 30 min; the column temperature was set to 35 °C, and APCI/MS was used in the positive‐ion acquisition mode. The TAG retention displayed a special order and was summarized to fit as follows: S‐ECN (special equivalent carbon number) = 2CN (carbon number) ? 3dB (double bond number) – 5uFA (unsaturated fatty‐acid number). Then, the LC–MS method was applied to separate TAG in 6 vegetable oils, resulting in the recognition of 27 TAG in corn oil, 21 TAGs in olive oil, 22 TAG in sunflower seed oil, 28 TAG in soybean oil, 25 TAG in sesame oil, and 31 TAG in peanut oil. The TAG separation through the LC–MS method was rapid, reproducible, and durable.