Margarine from Organogels of Plant Wax and Soybean Oil

Organogels obtained from plant wax and soybean oil were tested for their suitability for incorporation into margarine. Sunflower wax, rice bran wax and candelilla wax were evaluated. Candelilla wax showed phase separation after making the emulsion with the formulation used in this study. Rice bran wax showed relatively good firmness with the organogel, but dramatically lowered firmness for a margarine sample. Sunflower wax showed the greatest firmness for organogel and the margarine samples among the three plant waxes tested in this study. Firmness of the margarine containing 2–6 % sunflower wax in soybean oil was similar to that of margarine containing 18–30 % hydrogenated soybean oil in soybean oil. The firmness of commercial spread could be achieved with about 2 % sunflower wax and that of commercial margarine could be achieved with about 10 % of sunflower wax in the margarine formulation. Dropping point, DSC and solid fat content of the new margarine containing 2–6 % sunflower wax showed a higher melting point than commercial margarine and spreads.     

Evaluation of Beeswax,Candelilla Wax,Rice Bran Wax,and Sunflower Wax as Alternative Stabilizers for Peanut Butter

Four natural waxes were evaluated as stabilizers in peanut butter. The potential advantage of using natural waxes would be the replacement of current stabilizers such as hydrogenated or tropical oils, thereby reducing saturated fats and satisfying clean label requirements. Beeswax (BW), candelilla wax (CLW), rice bran wax (RBW), sunflower wax (SFW), and a commercial peanut butter stabilizer, hydrogenated cottonseed oil (HCO), were added to three natural peanut butter brands at levels ranging from 0.5% to 2.0% (w/w) and tested for accelerated oil release, long-term stability, firmness, and rheology. At levels ≥0.5%, all waxes improved oil-binding capacity (OBC). SFW and HCO had the highest OBC, followed by RBW, CLW, and BW. All waxes reduced the amount of oil separation after 6 months at 22 ± 2 °C. HCO followed by SFW reduced oil separation the most, but there were no significant differences between stabilizers at 1–2%. Firmness and yield stress increased with increasing stabilizer level, with SFW increasing firmness the most, followed by HCO, RBW, and CLW, while BW had the lowest effect. The results indicate that the waxes may be feasible replacements for hydrogenated oils as peanut butter stabilizers, but levels would need to be optimized depending on the product characteristics and wax type.     

Evaluating the Oil‐Gelling Properties of Natural Waxes in Rice Bran Oil: Rheological,Thermal, and Microstructural Study

The main objective of this research was to enhance the understanding of the oil‐structuring properties of natural waxes. A number of natural food‐grade waxes were evaluated for their oil‐gelling properties using a combination of techniques, including rheology, differential scanning calorimetry, and polarized light microscopy. Based on the rheological measurements (oscillatory, flow, and thixotropic behavior), we found that rice bran wax, carnauba Brazilian wax and fruit wax showed weak gelling behavior in rice bran oil (prepared at concentrations as high as 5 % w/w), exhibiting relative low elastic moduli that displayed a high frequency dependency. On the contrary, carnauba wild wax, berry wax, candelilla wax, beeswax, and sunflower wax were efficient oleogelators forming strong gels at concentration of <2 % w/w. We attempt to explain these observed differences in gelling behavior by crystal morphology, network formation, and the final amount of crystalline phase.     

Physical Properties of Rice Bran Wax in Bulk and Organogels

Differential scanning calorimetry (DSC), optical microscopy, and X-ray diffraction (XRD) were used to examine the thermal behavior, crystal structure, and crystal morphology of rice bran wax (RBX) in bulk and oil–wax mixtures, and to compare them with those of carnauba wax (CRX) and candellila wax (CLX). The RBX employed in the present study was separated from rice bran oil by winterization, filtration, refinement, bleaching, and deodorization. The RBX crystals melted in the bulk state at 77–79 °C with ΔH _melting = 190.5 J/g, which is quite large compared with CLX (129 J/g) and CRX (137.6 J/g). XRD data of the RBX crystals revealed O_⊥ subcell packing and a long spacing value of 6.9 nm. Thin long needle-shaped crystals were observed in the mixtures of RBX and liquid oils [olive oil and salad oil (canola:soy bean oil = 50:50)]; therefore, the dispersion of RBX crystals in these liquid oils was much finer than that of CRX and CLX crystals. Organogels formed when the mixture of every plant wax and liquid oil was melted at elevated temperature and cooled to ambient temperature. However, the mixture of RBX and olive oil at a concentration ratio of 1:99 wt.% formed an organogel at 20 °C, whereas the lowest concentration necessary for CRX to form an organogel in olive oil was 4 wt.% and that for CLX was 2 wt.%. Observation of the rate of gel formation using DSC and viscosity measurements indicated that the gel structure formed soon after RBX crystallized, whereas a time delay was observed between the organogel formation and wax crystallization of CRX and CLX. These results demonstrate RBX’s good organogel-forming properties, mostly because of its fine dispersion of long needle like crystals in liquid oil phases.     

Effect of oil unsaturation and wax composition on stability,properties and food applicability of oleogels

Oleogelation is emerging as one of the most exigent oil structuring technique. The main objective of this study was to formulate and characterize rice bran/sunflower wax-based oleogels using eight refined food grade oils such as sunflower oil, mustard oil, soybean oil, sesame oil, groundnut oil, rice bran oil, palm oil, and coconut oil. Stability and properties of these oleogels with respect to oil unsaturation and wax composition were explored. Sunflower wax exhibited excellent gelation ability even at 1%–1.5% (w/v) concentration compared to rice bran wax (8%–10% w/v). As the oleogelator concentration increased, peak melting temperature also increased with increase in strength of oleogels as per rheological studies. X-ray diffraction and morphological studies revealed that oleogel microstructure has major influence of wax composition only. Sunflower wax oleogels unveiled rapid crystal formation with maximum oil binding capacity of 99.46% in highly unsaturated sunflower oil with maximum polyunsaturated fatty acid content. Further, the applicability of this wax based oleogels as solid fat substitute in marketed butter products was also scrutinized. The lowest value of solid fat content (SFC) in oleogel was 0.20% at 25°C, resembling closely with the marketed butter products. With increase in oil unsaturation, oleogels displayed remarkable reduction in SFC. Depending upon prerequisite, oleogel properties can be modulated by tuning wax type and oil unsaturation. In conclusion, this wax-based oleogel can be used as solid fat substitute in food products with extensive applications in other fields too.     

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.     

Physical Properties of Beeswax,Sunflower Wax,and Candelilla Wax Mixtures and Oleogels

To be able to tailor and optimize the physical properties of oleogels for various food applications, more information is needed to understand how different gelators interact. Therefore, the objectives of this study were to evaluate the interactions between binary mixtures of beeswax (BW), candelilla wax (CLW), and sunflower wax (SFW) in pure form as well as in 5% wax oleogels made with soybean oil, in terms of their crystallization and melting properties, crystal morphology, solid fat content, and gel firmness. CLW:BW mixtures had eutectic melting properties, and oleogels from these mixtures with 40:60 to 90:10 CLW:BW were firmer compared to oleogels made with one wax. The main components in SFW and BW appeared to cocrystallize or crystallize at the same temperature, but nonlinear changes in melting point and solid fat content profile of oleogels prepared with the mixed waxes indicated that SFW dominated oleogel formation. In addition, oleogels prepared with mixtures of SFW and BW had lower firmness compared to oleogels prepared with one wax, indicating an incompatibility between the two waxes. The main wax components in SFW and CLW never cocrystallized, and low levels of CLW appeared to prevent SFW from forming a crystalline platelet network. This resulted in low firmness of oleogels made from mixtures of 90:10 to 60:40 SFW:CLW compared to oleogels prepared with one wax. However, the firmest oleogels of all mixtures were made from 10:90 SFW:CLW. Changes in gel firmness and melting properties with mixed wax oleogels were likely to be due to changes observed in the crystal size and morphology. In addition, the firmest gels were shown to result from mixtures that were predicted to have >40% hydrocarbon content, and a high hydrocarbon to wax ester ratio, but minor components such as free fatty acids and fatty alcohols may have also influenced firmness.     

Properties of Oleogels Formed With High‐Stearic Soybean Oils and Sunflower Wax

In an effort to develop alternatives for harmful trans fats produced by partial hydrogenation of vegetable oils, oleogels of high‐stearic soybean (A6 and MM106) oils were prepared with sunflower wax (SW) as the oleogelator. Oleogels of high‐stearic oils did not have greater firmness when compared to regular soybean oil (SBO) at room temperature. However, the firmness of high‐stearic oil oleogels at 4 °C sharply increased due to the high content of stearic acid. High‐stearic acid SBO had more polar compounds than the regular SBO. Polar compounds in oil inversely affected the firmness of oleogels. Differential scanning calorimetry showed that wax crystals facilitated nucleation of solid fats of high‐stearic oils during cooling. Polar compounds did not affect the melting and crystallization behavior of wax. Solid fat content (SFC) showed that polar compounds in oil and wax interfered with crystallization of solid fats. Linear viscoelastic properties of 7% SW oleogels of three oils reflected well the SFC values while they did not correlate well with the firmness of oleogels. Phase‐contrast microscopy showed that the wax crystal morphology was slightly influenced by solid fats in the high‐steric SBO, A6.     

Physical Properties of Aqueous Solutions of Pectin Containing Sunflower Wax

The aim of this study is to investigate the physical properties of aqueous solutions of pectin (PA) containing sunflower wax (SFW), which are used as a basis for producing edible films. The stability and the rheological and microstructural characteristics of SFW/PA mixtures were evaluated. SFW/PA mixtures formed oil-in-water emulsions that were milky and opaque in appearance and were stable towards phase separation. Polarized micrographs revealed the presence of wax crystals, whose size decreased as pectin concentration increased. The rheological behavior of the aqueous solutions of pectin containing different amounts of SFW were best described by the generalized power law model of Herschel–Bulkley (H–B), which gave the best fit in all the range of shear rate values. Apparent viscosities and yield stress were determined using this model, and both properties increased with increasing pectin content. The apparent viscosity values were between 0.0095 and 0.1031 Pa s. SFW addition resulted in a small decrease in viscosity for emulsions formulated with 1 and 2 % PA, but the opposite effect was observed for emulsions formulated with 3 % PA. In addition, shear stress values were higher for emulsions with higher PA content, but were not affected by SFW addition.     

The Effect of Addition of High-Melting Monoacylglycerol and Candelilla Wax on Pea and Faba Bean Protein Foam-Templated Oleogelation

Use of oleogels prepared from hydrocolloids has recently gained considerable attention as an alternative for trans and saturated fats. Lately, pulse proteins such as faba bean protein and pea protein have been successfully used to prepare oleogels using a foam-templated approach. Although the pulse proteins are healthy oleogelators, high oil loss and low quality of cake baked using pulse protein-stabilized oleogels due to its poor rheological properties challenged its use. The present study explored whether the addition of small amount of high-melting monoglyceride (MAG) or candelilla wax (CW) can be used to improve the oil binding capacity, rheological properties, and baking qualities of pulse protein-stabilized oleogels composed of 5% faba bean or pea protein concentrate with 0.25% xanthan gum foams. Different concentrations (0.5–3%) of MAG or CW were dissolved in canola oil at 80 °C, followed by addition into the freeze-dried protein-polysaccharide foams (pH 7) and quickly transferred to a refrigerator to facilitate the formation of oleogels. The crystallized additives were found to be reinforcing the protein foam network in the oleogels. With increase in concentration of CW and MAG, the oil binding capacity, firmness, cohesiveness, and storage moduli of the oleogels were increased. Oleogels with and without MAG or CW were then characterized and tested for their performance as a shortening replacer in model baked cakes. Findings showed improved textural properties of cake upon addition of MAG in the foam-templated oleogels, however, compared to the shortening, negative effect on cake hardness and chewiness was still observed with the oleogels.     

Increasing the firmness of wax-based oleogels using ternary mixtures of sunflower wax with beeswax:candelilla wax combinations

Oleogels were prepared with 5% wax in soybean oil using mixtures of beeswax (BW) and candelilla wax (CLW) with ratios of 10:90, 30:70, 50:50, and 60:40 BW:CLW, and the same series where 10% of the total wax was substituted with sunflower wax (SFW). The hypothesis that SFW would increase the firmness of the oleogels without affecting the melting properties was tested. Firmness of one-wax oleogels decreased from SFW > CLW > BW. Oleogels with 50:50 BW:CLW and 60:40 BLW:CLW had equal firmness to pure 5% SFW oleogels. SFW significantly increased oleogel firmness and reduced the softening that occurred between 4°C and 22°C. Increased firmness was also found with rice bran wax and behenyl-behenate (C44) addition, but not with wax esters with chain lengths ranging from 30 to 40 carbons (C30 to C40). By differential scanning calorimetry, SFW significantly decreased the melting point of oleogels with 10:90 and 30:70 BW:CLW mixtures but significantly increased the melting point of those with 50:50 and 60:40 BW:CLW mixtures. However, the solid fat content melting curves were not significantly influenced by SFW addition. These results indicate that mixed wax oleogels had greater hardness and elasticity, and that the long chain wax esters contributed by SFW helped to improve the strength of oleogels without negatively affecting their melting properties.     

Determining the structure and stability of essential oil-sunflower wax and beeswax oleogels

In this study, essential oil oleogels were produced using eucalyptus, lavender, lemon peel and tea tree oils with sunflower and beeswax. The physicochemical, thermal, textural, and structural features of the oleogels were determined. For the essential oils used, an addition level of less than 15% of beeswax (BW) was insufficient to form stable oleogels, whereas an addition level of 10% of sunflower wax (SW) was sufficient to form stable oleogels. The acid and peroxide values of the gels were higher than those of the oils. All of the oleogels exhibited peaks around 3.70 and 4.10, indicating the presence of β' polymorphic forms. The hardness and stickiness values of the oleogels were influenced by the type and level of wax addition, as well as the viscosity of the oil used. Based on the thermal analysis results, the oleogels based on beeswax exhibited lower melting properties compared to those based on sunflower wax. The thermogravimetric data indicated that the polymeric matrices formed by the waxes, which depended on the type and level of wax addition, affected the vaporization of the volatiles. In conclusion, oleogels represent a green and sustainable approach for reducing the loss of volatile or bioactive compounds from various essential oils, which are widely used in the food, cosmetics, and pharmaceutical industries.     

Impact of ultrasound on oil yield and content of functional food ingredients at the oil extraction from sunflower

In this study, the effect of ultrasound-assisted extraction (UAE) on oil yield and content of functional food ingredients of hulled and non-hulled sunflower is discussed and compared with conventional extraction methods. The optimum extraction parameters for UAE were as follows: n-hexane as extracting solvent, average particle size 250 ± 12 µm, extraction time 2 h, solid-to-solvent ratio 1:12, ultrasound frequency 24 kHz and temperature 50°C. Furthermore, the chromatograph showed that sunflower oil extracted by the UAE was rich in α-Linolenic acid (ω-3). In addition, a marginal reduction in peroxide values and tocopherols were determined.     

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.     

Cellular ceramics by slip casting of emulsified suspensions

Cellular ceramics were processed by slip casting of alumina suspensions emulsified with sunflower oil. A model behavior was derived on assuming that the templating dispersed phase and its droplet size distribution are retained as porosity in the resulting cellular ceramics, whereas the continuous ceramic suspension evolves to dense struts and thin inter-pore walls. Representative values of solid load and oil to suspension ratio were selected to seek close packed spatial distribution of nearly spherical. Stirring rate and additions of surfactant were also varied for greater flexibility in adjusting droplet size and rheology of the corresponding emulsified suspensions; this also contributes to minimize undue losses of porosity, relative to the model behavior, and determines microstructural features such as size distributions and average cell size.     

沥青质引发的蜡油体系结蜡层分层现象及分层规律

利用自主研发的Couette结蜡装置,对蜡含量相同的油样1(不含沥青质)和油样2[含0.75%(质量分数)沥青质]进行结蜡实验,并研究其结蜡层的分层现象和分层规律。通过对油样1和油样2结蜡表层和底层的宏观形貌、DSC放热、析蜡量、蜡晶微观形貌的分析发现:油样1结蜡层无明显分层现象,而油样2结蜡层分层现象明显,沥青质的加入导致了结蜡层的分层。与结蜡表层相比,油样2结蜡底层的析蜡点、蜡含量与沥青质含量显著升高,蜡晶形貌发展为致密的类球状大蜡晶。油样2结蜡表层沉积量随壁温的升高、油壁温差和转速的增大而减小;结蜡底层沉积量随壁温升高而减小,随油壁温差和转速的增大而增大;总的蜡沉积量随壁温的升高和转速的增大而减小,随油壁温差的增大先增大后减小。     

Analysis of the wax ester fraction of olive oil and sunflower oil by gas chromatography and gas chromatography-mass spectrometry

The wax ester fractions of solvent-extracted sunflower oil and “extra virgin” olive oil were obtained by solid-phase extraction and subsequently subjected to gas-chromatographic and gas chromatographic-mass spectrometric analysis. The comprehensive qualitative analysis of these fractions, which was carried out by the interpretation of mass spectral data, revealed several types of wax esters. In olive oil, shortchain, even-numbered wax esters, saturated and unsaturated long-chain, even-numbered wax esters, benzyl esters, and the diterpenic esters phytyl and geranylgeranyl ester (the latter as a minor component) are present. With the exception of benzyl esters, all these esters occur in sunflower oil as well, but in considerably different amounts compared to those in olive oil. Whereas unsaturated wax esters are present in a negligible amount, diterpenic esters, mainly geranylgeranyl esters, represent the major part of the wax ester fraction.     

Wax composition of sunflower seed oils

Waxes are natural components of sunflower oils, consisting mainly of esters of FA with fatty alcohols, that are partially removed in the winterization process during oil refining. The wax composition of sunflower seed as well as the influence of processing on the oil wax concentration was studied using capillary GLC. Sunflower oils obtained by solvent extraction from whole seed, dehulled seed, and seed hulls were analyzed and compared with commercial crude and refined oils. The main components of crude sunflower oil waxes were esters having carbon atom numbers between 36 and 48, with a high concentration in the C₄₀−C₄₂ fraction. Extracted oils showed higher concentrations of waxes than those obtained by pressing, especially in the higher M.W. fraction, but the wax content was not affected significantly by water degumming. The hull contribution to the sunflower oil wax content was higher than 40 wt%, resulting in 75 wt % in the crystallized fraction. The oil wax content could be reduced appreciably by hexane washing or partial dehulling of the seed. Waxes in dewaxed and refined sunflower oils were mainly constituted by esters containing fewer than 42 carbon atoms, indicating that these were mostly soluble and remained in the oil after processing.     

Effect of Attapulgite Pore Size Distribution on Soybean Oil Bleaching

The pore size distribution and specific surface area of the attapulgite was a crucial parameter for the uptake of pigments of oil. Bleaching of the soybean oil with three attapulgites with different pore size distribution, which were assigned a, b, and c, respectively was investigated. The specific surface area and the pore size distribution of the attapulgites were characterized. The Freundlich isotherm analysis was used to evaluate the sorption capacity of the three attapulgite. Sample b gave the highest surface area and sample c the lowest. Sample b exhibited a wider pore distribution (8–65 Å) whereas samples a and c had more micropores smaller than 15 Å. Sample a, in contrast to samples b and c, was characterized by some larger pores (100–170 Å). The sorption capacity followed the sequence: attapulgite sample c > attapulgite sample a > attapulgite sample b. The sorption capacity was decided by the pore size distribution. The more pores with a distribution range 8–32 Å (i.e., close to the diameter of the pigments), the more pigments removed. The attapulgite sample c, which had most pores (8–32 Å) was the best.