A Novel Propolis Wax-Based Organogel: Effect of Oil Type on Its Formation,Crystal Structure and Thermal Properties

In this work, the potential application of propolis wax (PW) as a novel organogelator was investigated in different oils (canola, sesame, sunflower and flaxseed oil). PW at 2% (w/w) concentration produced a thick organogel at 5, 10 and 15 °C, with needle‐like crystals, suggesting that PW is a relatively efficient structuring agent for organogel formation. The oil binding capacity of the organogel with canola oil was lower than that of the other organogels, and the gelling time of flaxseed organogel with lower oil viscosity was shorter. The X‐ray diffraction measurements of the crystals showed β′‐form crystals, with no influence of oil type. In FTIR results, no chemical intermolecular interactions that were observed indicated physical bonds in the organogel network. DSC analysis was carried out to obtain greater insight into the thermal behavior of PW organogels. No significant differences were observed. The textural properties of PW organogels were stable over 30 days of storage. Flaxseed oil organogel had the greatest firmness and stickiness. These results showed the effect of oil viscosity on PW gel behavior.     

Organogelation Capacity of Epicuticular and Cuticular Waxes from Flax and Wheat Straws

Valorization of the agri-food industry by-products could contribute to curb issues related to food security and environmental problems. Flax and wheat seeds are major products of this industry, but their production is associated with tons of straws that can be valorized for their cuticular and epicuticular waxes. We aimed to determine the organogelation capacity of epicuticular waxes in comparison to cuticular waxes from both flax and wheat straws. Epicuticular waxes from flax and wheat straws have structured canola oil at 2% and 4% (w/w), respectively, whereas cuticular waxes from flax and wheat straws required critical concentrations of 4% and 5% (w/w), respectively. Characterization of the organogelation capacity (onset of crystallization temperature, temperature of phase transition, crystal morphology, solid fat, crystalline structure, and oil binding capacity) was also carried out. The high onset of crystallization temperature (38.1 ± 1.2°C), the phase transition at high temperature (38 ± 1.5°C), and capacity to structure canola oil at low concentration showed that epicuticular wax from flax straw is a promisor fat substitute, presenting organogelation properties comparable to the best results obtained in the literature for other vegetal waxes.     

Comparative Study of Table Margarine Prepared from Moringa oleifera Seed Oil‐Palm Stearin Blend and Commercial Margarines: Composition,Thermal, and Textural Properties

This study aims to produce an oleic acid‐rich table margarine from Moringa oleifera seed oil (MoO)‐palm stearin (PS) blend (70:30, w/w) and compare its composition, thermal behavior, and textural properties during storage with those of commercial margarines (CM1 and CM2). The major fatty acid in MoO/PS blend, CM1 and CM2 is oleic acid (67.85%, 38.54%, and 35.35%, respectively). Hence, many of their triacylglycerols are derived from the acid. MoO/PS blend has a higher complete melting temperature (43.50 °C) compared to CM1 (35.50 °C) and CM2 (35.53 °C). The solid fat content (SFC) of MoO/PS blend at 10 °C (28.7%) is lower than CM1 (32%) and CM2 (68.4%). However, the MoO/PS blend has a higher SFC (6.47%) at 35 °C compared to CMs. At 20 °C, the viscosity of experimental blend margarine (EBM) decreases but CM1 and CM2 increase at the end of the storage study. After 8 weeks of storage, all margarines are harder and CM2 is the hardest. The adhesiveness of EMB and CM2 is similar to the fresh samples while CM1 is more adhesive after storage. In short, it is possible to produce an oleic acid‐enriched margarine from MoO/PS blend that has better textural properties. Practical Applications: Moringa oleifera seed oil is one of the superior oils that contains high levels of oleic acid. However, its high iodine value and low melting point limit its application in the production of margarine. This study shows that direct blending of M. oleifera seed oil with palm stearin could produce margarine with high oleic acid contents and better textural properties in terms of viscosity, hardness, and adhesiveness. The informative data provide supporting evidence for blending of M. oleifera seed oil with palm stearin to produce margarine that could overcome the issues that hinder the M. oleifera seed oil from being produced into margarine.     

Optimizing Conditions for the Purification of Linoleic Acid from Sunflower Oil by Urea Complex Fractionation

The separation and purification of linoleic acid (LA) from sunflower seed oil by urea complex fractionation was studied. Crystallization reaction conditions of urea inclusion were optimized using the response surface method, and the optimal model was developed. Using the linear weighting method of the fitting model for optimization, the optimal balance between the purity and the recovery of LA was obtained. Under optimal conditions, the purity of LA was 87.8%, and the recovery was 83.4% at a urea-to-fatty acids ratio (w/w) of 0.94, 95% ethanol-to-urea (v/w) of 5.00, a crystallization temperature of 18.0 °C, and a crystallization time of 5.0 h. Verification results revealed that the predicted values from these models were reasonably close to the experimentally observed values.     

Lecithin gum rheology and processing implications

The rheology of canola, sunflower, and soybean lecithin gum was examined by studying samples of different moisture contents produced in a batch evaporator (70°C, 0.1 atm). Soybean lecithin was found to have the lowest viscosity, approximately 10 poise (100 s⁻¹, 70°C), compared to canola and sunflower lecithin with viscosities of approximately 90 and 90,000 poise, respectively. The high sunflower viscosity was attributed to the presence of long-chain waxes. Lecithin gum was shown to change from a Bingham (water continuous phase) to a pseudoplastic (oil continuous phase) type fluid as the moisture content of the lecithin gum decreased. The viscosity maxima occurred between 6.9 and 19.3% moisture content (100 s⁻¹), with the variation found to be related to the oil/water ratio of the system. Rheological results indicated that vertical scraped surface evaporator design could be optimized through the addition fluidizing of agents prior to the evaporator and/or increased heating at the evaporator outlet.     

Cooling rate and dilution affect the nanostructure and microstructure differently in model fats

The effects of cooling rate and solid mass fraction on the polymorphism, nano and microstructure, thermal and rheological properties of binary mixtures of fully hydrogenated canola oil and canola oil at 20°C have been studied. The β‐polymorph was observed in fully hydrogenated canola oil (FHCO) when crystallized at slow cooling rates (0.1C°/min), however crystallization at higher cooling rates (0.7 and 10°C/min) resulted in the formation of the α form. The β‐polymorph was detected in all the binary mixtures of FHCO/canola oil and was not affected by crystallization at different cooling rates. Melting thermograms obtained from 100% FHCO displayed three melting peaks, associated with the development of the β‐polymorph via α→ β′→ β‐polymorphic transition in the DSC pan. Some solubilization of solid FHCO into canola oil was observed and the solubility was proportionally higher with increasing liquid oil fraction. The strong influence of the matrix concentration on micro/nanoscale structure was demonstrated by characterization of crystal size using cryogenic transmission electron (Cryo‐TEM) and polarized light microscopy (PLM). Crystallization under higher cooling rates lead to formation of smaller nano and meso‐structural elements. Furthermore, oscillatory rheology showed the influence of structural elements' size and polymorphism on material strength. The shear storage modulus (G′) of the mixtures was higher when crystallized at fast cooling rates (10°C/min). In contrast, for pure FHCO, G′ increased by lowering the cooling rate and the highest storage modulus was observed after crystallization at 0.1°C/min.     

Antioxidant Activity of Amaranth Protein Hydrolysate Against Thermal Oxidation of Vegetable Oils

The antioxidant capacity of amaranth protein hydrolysate (AH) during the thermally induced oxidation of two different vegetable oils, sunflower oil (SO) and canola oil (CO), was assessed by differential scanning calorimetry by means of isothermal and non‐isothermal assays. Interactions between AH and tocopherols were also analyzed. In both oils, AH (10 % w/w) produced an increase in the induction period in isothermal assays, presenting a synergistic effect with tocopherols. In the case of non‐isothermal assays, thermograms of oils with AH showed a significant diminution in the second exothermic peak, suggesting an inhibition of the decomposition of primary to secondary oxidation products. In addition, AH produced an increase in the oxidation rate constant (k) value at low temperatures being more evident in the case of canola oil. However, this effect decreased as a function of the temperature increase, which suggests that AH would have a pro‐oxidant effect at low temperatures but a heat stabilizing effect at high temperatures (above 210 °C for SO and 190 °C for CO).     

Utilization of green seed canola oil for biodiesel production

Increasing percentage of green canola seed every year is a serious problem for canola growers. Chlorophyll content of this oil is very high, which makes it more susceptible to photo‐oxidation and ultimately the oxidation stability of the oil is very reduced. Hence green seed canola oil is underutilized for edible purposes. The present work is an attempt to produce high‐quality biodiesel from green seed canola oil and methanol, ethanol and various mixtures of methanol and ethanol using KOH as a catalyst. A mixture of alcohols improved the rate of reaction. After transesterification of green seed canola oil using KOH, the chlorophyll content of the oil was decreased substantially (from 22.1 ppm to 10.3 ppm). Characteristics of the esters prepared from green seed canola oil were well within the limits of ASTM standards. Lubricity of the green seed oil esters was excellent (20% decrease in wear scar area) when added at 1 vol% to the base fuel. Oxidation stability is crucial for long‐term storage of the fuel. Oxidation stability index (OSI) of green seed esters was 4.9 h at 110 °C, which is much less than the European Standard (6 h at 100 °C). The low oxidation stability of green seed esters is attributed to its higher chlorophyll (10.3 ppm) content. An attempt was also made to reduce the chlorophyll content of the oil before transesterification using activated carbon treatment, and it was observed that chlorophyll content was reduced from 22.1 to 2.2 ppm. Copyright © 2006 Society of Chemical Industry     

Comparisons of Biodiesel Produced from Unrefined Oils of Different Peanut Cultivars

Biodiesels were prepared according to standard procedures from unrefined oils of eight commercially available peanut cultivars and compared for differences in physical properties important to fuel performance. Dynamic viscosity, kinematic viscosity and density were measured from 100 to 15 °C, and differences (p < 0.05) in these physical properties occurred more frequently at lower temperatures when comparing the different cultivars. Unlike data for the oil feedstocks, no meaningful correlations among biodiesel fatty acid profiles and either fuel viscosity or density were observed. Low temperature crystallization of the peanut biodiesels was measured via differential scanning calorimetry. Increased concentrations of long chain saturated fatty acid methyl esters (FAME) were associated with an increased propensity for low temperature crystallization, and the single FAME category most associated with low temperature crystallization was C:24. Tempering at 10 °C followed by analysis of the soluble fractions (winterization), improved crystallization properties and confirmed the importance that long chain saturated FAMEs play in the final functionality of peanut biodiesel. Peanut data is also compared to data for canola and soy biodiesels, as these feedstocks are more common worldwide for biodiesel production. Overall, this work suggests that minimizing the concentration of long chain saturated FAMEs within peanut biodiesel, either through processing and/or breeding efforts would improve the low temperature performance of peanut biodiesel.     

Carbon-based solid acid catalyst from de-oiled canola meal for biodiesel production

A carbon-based acid catalyst was prepared by the sulfonation of partially carbonized de-oiled canola meal (DOCM), a by-product of canola seed processing. Partial carbonization of DOCM was carried out at 300 and 400 °C and the partially carbonized material prepared at 400 °C was steam activated to improve its surface properties. Four types of carbon catalysts were prepared using the partially carbonized material and DOCM by concentrated sulfuric acid treatment. The spectral and elemental analysis clearly indicated that the catalyst had enough acidic sites in the form of sulfonate groups having the ability to promote esterification reaction. The catalyst partially carbonized at 300 °C established various functional groups such as aromatic carbon atoms, phenolic-OH, COOH, and carbonyl groups on the surface as evidenced by the MAS ¹³C NMR and FTIR spectra. The catalyst produced by partial carbonization at 300 °C followed by sulfuric acid treatment showed better performance towards esterification of oleic acid and high FFA canola oil. The maximum conversion reached 93.8% after 24 h at 65 °C using 1:60 mol:mol of FFA to methanol and 7.5 wt.% of catalyst to FFA. The performance of the catalyst was reduced gradually during its recycling and reached to 40.5% at the end of 4th cycle.     

Using SPME-GC/MS to Evaluate Acrolein Production in Cassava and Pork Sausage Fried in Different Vegetable Oils

This work presents the quantification of acrolein in cassava and pork sausage fried (temperature of 170 °C) in five different vegetables oils: canola, palm, sunflower, soybean and corn using a method of solid-phase microextraction (SPME) combined with gas chromatography and mass spectrometry. The results showed that the highest concentration of acrolein was found in samples fried in sunflower oil and canola oil. The concentration of acrolein in pork sausage (3.7 and 2.0 ng/g/g) was lower than in cassava (10.2 and 3.8 ng) when fried in sunflower and soybean oils, respectively. In contrast, when the denser oils (canola and palm) were used for frying, the concentration of acrolein in pork sausage (6.3 and 3.8 ng/g) was higher than in cassava (3.7 and 2.8 ng/g). Using corn oil, the concentrations of acrolein in both cassava and sausage were similar (approximately 5 ng/g). The viscosity of the oil, the fatty acid composition, especially the level of saturated and unsaturated fatty acids from the food, and oil uptake are factors that influence the acrolein concentration found in fried food.     

Thin-film test to investigate liquid oxypolymerization of nonvolatile analytes: Assessment of vegetable oils and biodegradable lubricants

A thin-film oxidation test was developed to investigate liquid oxypolymerization of nonvolatile analytes. Gel permeation chromatography (GPC) showed that the test delivered the required degree of oxidation with better than ±5% accuracy. The following oils were ranked according to their decreasing resistance to oxypolymer formation at 150°C: 90% oleic sunflower oil, triolein, meadowfoam oil, castor oil, canola oil, lesquerella oil, and soybean oil. Higher degrees of oxidation demonstrated the occurrence of oxidative gelation. Oxypolymerization tendencies of hydraulic fluids based on canola and rapeseed oils were comparable to those of canola oil without additives. The relative amount of C-C polyunsaturation present in the fatty acid chain was a major differentiating factor. However, oxidation inhibitors also reduced the rates of oxypolymerization, as demonstrated by sunflower oil-based hydraulic fluid. Canola and rapeseed lubricants needed better oxypolymerization control.     

Biodiesel from canola oil using a 1 : 1 molar mixture of methanol and ethanol

Canola oil was transesterified using a 1 : 1 molar mixture of methanol and ethanol (M/E) with potassium hydroxide (KOH) catalyst. The effects of catalyst concentration (0.5–1.5 wt‐%), molar ratio of M/E to canola oil (3 : 1 to 20 : 1) and reaction temperature (25–75 °C) on the percentage yield measured after 2.5 and 5.0 min were optimized using a central composite design. A maximum percentage yield of 98% was obtained for a catalyst concentration of 1.1 wt‐% and an M/E to canola oil molar ratio of 20 : 1 at 25 °C at 2.5 min, whereas a maximum percentage yield of 99% was obtained for a catalyst concentration of 1.15 wt‐% and all molar ratios of reactants at 25 °C at 5 min. Statistical analysis demonstrated that increasing catalyst concentration and molar ratio of reactants resulted in curvilinear and linear trends in percentage yield, both at 2.5 and 5 min. However, reaction temperature, which affected the percentage yield at 2.5 min linearly, was insignificant at 5 min. The resultant mixed methyl/ethyl canola esters exhibited enhanced low‐temperature performance and lubricity properties in comparison to neat canola oil methyl esters and also satisfied ASTM D6751 and EN 14214 standards with respect to oxidation stability, kinematic viscosity, and acid value.     

Comparison of the pomegranate seed oil organogels of carnauba wax and monoglyceride

The aims of this study were to prepare organogels from pomegranate seed oil (PO) with carnauba wax (CW) and monoglyceride (MG), compare the organogels with a commercial margarine (CM) and evaluate 3 months storage stability. At 3% organogelator addition, no gels were formed, while at 7 and 10% additions, the oil binding capacities increased and were always higher in CW organogels, with crystal formation times of 8.0 to 14.0 min. Solid fat content (SFC) of the CW organogels varied between 2.96 and 8.71% at 20°C, while MG gels had 2.89–9.43%, and CM had 29.73% SFC. The peak melting temperatures of the CW organogels ranged from 74.73 to 75.74°C and MG organogels ranged from 11.09 to 50.63°C, whereas CM product exhibited 45.92°C peak melting temperature. The hardness of CW organogels was higher than that of MG organogels. The organogels showed potential as spreadable products. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41343.     

Comparison of Ethyl Acetate with Hexane for Oil Extraction from Various Oilseeds

The aim of the current research was to determine a less hazardous, cheaper and less toxic alternative solvent for hexane for extraction of oil from different oilseeds showing equivalent oil yield and oil quality. A full factorial design with three levels of extraction temperature (80, 100 and 120 °C) and three levels of extraction time (40, 65 and 90 min) with constant solvent to seed ratio value of 4:1 was used to extract the oil. Maximum oil was recovered from canola followed by flax, mustard and camelina. The oil content of canola was found in range of 21.08–36.44, and 25.12–40.38 % for hexane and ethyl acetate, respectively. The heating values of oil extracted from all oilseeds using hexane and ethyl acetate were found in the range of 38.04–39.98 and 37.98–39.37 MJ/kg, respectively. Least viscosity was found for flax seed using hexane followed by camelina, canola and mustard as compared to ethyl acetate. Viscosity of flax oil ranged from 27.23–37.19, and 31.16–55.52 cP for hexane and ethyl acetate solvents, respectively. Considering human safety, less environmental impact, comparable oil yield and quality parameters, ethyl acetate can be a promising alternative to hexane.     

Evaluation of Biodiesel Derived from <Emphasis Type="Italic">Camelina sativa</Emphasis> Oil

Biodiesel derived from camelina as well as other feedstocks including palm, mustard, coconut, sunflower, soybean and canola were prepared via the conventional base-catalyzed transesterification with methanol. Fatty acid profiles and the fuel properties of biodiesel from different vegetable oils were analyzed and tested in accordance with ASTM D6751. Camelina biodiesel contains 10–12%, 37–40%, and 48–50% saturated, monounsaturated and polyunsaturated components, respectively. Some fuel properties of camelina biodiesel are comparable to that of sunflower biodiesel including kinematic viscosity (40 °C), flash point, cloud point, cold filter plugging point, and oil stability index. However, camelina biodiesel exhibited the poorest oxidative stability, highest distillation temperature and has the highest potential to form coke during combustion, all of which are attributed to the high amounts of n-3-fatty acids in camelina oil. While neat camelina biodiesel may exhibit undesirable fuel properties, it is very comparable with soybean biodiesel at the B20 level.     

Pan-frying stability of NuSun oil,a mid-oleic sunflower oil

Pan-frying is a popular frying method at home and in many restaurants. Pan-frying stabilities of two frying oils with similar iodine values (IV)—mid-oleic sunflower oil (NuSun oil; IV=103.9) and a commercial canola oil (IV=103.4)—were compared. Each oil sample was heated as a thin film on a Teflon-coated frying pan at ∼180°C to a target end point of ≥20% polymer. High-performance size-exclusion chromatography analysis of the mid-oleic sunflower and canola oil samples indicated that the heated samples contained 20% polymer after approximately 18 and 22 min of heating, respectively. The food oil sensor values increased from zero to 19.9 for the canola sample and from zero to 19.8 for the mid-oleic sunflower sample after 24 min of heating. The apparent first-order degradation rate for the mid-oleic sunflower sample was 0.102±0.008 min⁻¹, whereas the rate for the canola sample was 0.092±0.010 min⁻¹. The acid value increased from approximately zero prior to heating to 1.3 for the canola sample and from zero to 1.0 for the mid-oleic sunflower sample after 24 min of heating. In addition, sensory and volatile analyses of the fried hash browns obtained from both oils indicated there were no significant differences between the two fried potato samples.     

Crystallization kinetics of organogels prepared by rice bran wax and vegetable oils

Rice bran wax (RBX) obtained during rice bran oil purification can form organogels in edible oils. The kinetics of crystallization and the viscous properties of RBX organogels were studied using differential scanning calorimetry (DSC), viscosity changes with varying temperature, hardness measurements by penetrometry, and synchrotron radiation X-ray diffraction (SR-XRD). The organogels were prepared by RBX in concentrations of 1%, 3%, 6%, and 10% on a weight basis in salad oil, olive oil, and camellia oil. The liquid oil type had no significant effect on the melting and crystallization temperatures of the RBX. However, the viscosity and the texture of the organogels differed with liquid oil type, temperature, and RBX concentration. Changes in the viscosity of the RBX organogels were monitored during cooling from 80°C to 20°C. Drastic viscosity changes occurred in accordance with the onset of crystallization in DSC thermographs obtained at a rate of 5°C/min. RBX in the olive oil and camellia oil mixtures had higher viscosity than RBX in the salad oil mixture, which correlates with the hardness obtained in texture measurements at 20°C. SR-XRD was used to clarify the crystal structures of the building blocks of the RBX organogels in salad oil. It was found that the RBX formed crystals with a long spacing of 7.3 ± 1 nm and short spacings of 0.41 ± 1 nm and 0.37 ± 1 nm. The intensity of the long-spacing pattern was remarkably weaker than that of the short-spacing patterns, which demonstrated strong anisotropy in the crystal growth of RBX crystal particles.     

Implementing an In Situ Alkaline Transesterification Method for Canola Biodiesel Quality Screening

Increasing demand for canola (Brassica napus) as an edible oil crop and biodiesel (B100) feedstock has encouraged genetic development for increased oil yields and expanded acreage in the US Northern Plains. Crop production environment and plant genetics influence metabolism and fatty acid composition, but the influence of this interaction on the resulting fatty acid methyl esters (FAME) is not clearly understood. The objective of this study was to develop a canola in situ transesterification (TE) method for facilitating the identification of genetic, abiotic or biotic factors impacting B100 quality, and to evaluate FAME quality properties from conventional TE (degummed oil) and in situ TE methods. In situ reactions containing 40 g canola flour conducted for 6 h at 60 °C with a 275:1:1.05 M ratio of methanol:triacylglycerol (TAG):KOH provided 80% conversion of seed lipid to FAME. Replicated reactions provided sufficient FAME volume for measuring several ASTM D6751-09 standards including cloud point, kinematic viscosity, acid value, moisture content, oxidative stability, and total glycerin, but adjustments are necessary to provide sufficient volumes for routine analysis of cold soak filtration test. The established in situ protocol would permit weekly analysis of 40 samples and the in situ TE method provides an opportunity to evaluate the impact of genetic or environmental factors on B100 quality.     

Crystallization characteristics of hydrogenated canola oil as affected by addition of palm oil

Addition of palm oil at levels of 5, 10 and 15% to selectively and nonselectively hydrogenated canola oil increased the time of isothermal crystallization at 20°C and delayed the appearance of the isothermal crystallization peak as determined by DSC. The degree of supercooling was also increased. Addition of palm oil to canola oil before selective or nonselective hydrogenation decreased the time of the appearance of the isothermal crystallization peak. Rates of crystallization were determined in selectively hydrogenated canola palm oil mixtures which followed first order kinetics.