We studied the thermomechanical and microstructural properties of oleogels developed with 2.1 to 15.7 Moles of monoglycerides/Mole of lecithin (MG/LC). The oleogels were developed (15°C) in vegetable (VO) and mineral (MO) oils using at each MG/LC 2% or 4% total mass of gelator. During oleogelation a synergistic MG-LC interaction existed deriving in the development of MG-LC cocrystals even below the gelators’ minimum gelling concentration. The cocrystals delayed the Lα→β polymorphic transition and worked as an active filler of the oleogels’ crystal network. In the VO, the oil with the highest relative polarity, the oleogels were structured by a network of β crystals where the cocrystals acted as an active filler. In the MO, the oil with the lowest relative polarity, the cocrystals’ development was favored while the Lα→β transition occurred just in the 15.7 MG/LC oleogels. Then, at all MG/LC the VO oleogels with 2% or 4% total gelator concentration achieved higher G’ than MO oleogels. However, the presence of β crystals will produce deleterious effects in shorter time in the VO oleogels than in the MO oleogels. In both oils the oleogels with the highest G’ and gel-like rheological behavior were achieved at 8.1 MG/LC, particularly at 4% total gelator concentration. Under these conditions the β polymorph was limited developed in the VO oleogels and completely absent in the MO oleogels. Then, we might tailoring the rheology of MG-LC oleogels with storage stability using as design variables the MG/LC, the total gelator concentration, and the polarity of the oil.
Cold-pressed hempseed oil (HSO) is known to have many health benefits due to many phytochemicals and high polyunsaturated fatty acids content. In this study, HSO oleogels were prepared with 3, 5, and 7% natural waxes including sunflower wax (SW), rice bran wax (RBW), beeswax, and candelilla wax to evaluate their potential as solid fat replacements in margarines and spreads. Firmness, crystal structures, and melting properties of these oleogels were evaluated. In general, wax-based HSO oleogels except for RBW-HSO oleogels had lower firmness and weaker crystal network than the corresponding soybean oil (SBO) oleogels. In contrast, RBW-HSO oleogels had similar firmness, comparable or stronger crystal network, and higher melting and crystallization enthalpies compared to those of SBO oleogels. After removing polar compounds from HSO, waxes except for RBW provided oleogels with greater firmness, higher melting and crystallization enthalpies, and stronger crystal network. Therefore, it was concluded that polar compounds negatively affected the physical properties of wax-HSO oleogels but not those of RBW-HSO oleogels. Margarine samples were prepared with SW- and RBW-HSO oleogels, and their firmness and melting properties were examined. The firmness of these margarines indicated that wax-HSO oleogels may achieve the firmness of commercial spreads with less than 3% wax while the firmness of stick margarines cannot be achieved even with 7% wax. Although the properties of wax-HSO oleogels should be further improved, they showed potential as solid fat replacements in margarines and spreads.
This study was carried out to optimize formulation for Heracleum Lasiopetalum (golpar) extract nanoencapsulation by response surface methodology (RSM). The primary emulsion was fabricated by (5-10 %) golpar extract (GE), (40-35 %) emulsifier span 80 (EM), and (50-60 %) sunflower oil (SO). The coating materials of nanoencapsulation were the composition of Lepidium sativum seed gum (LSG) and whey protein concentrate (WPC) at different ratios (1:0, 1:1, and 0:1). The yield of nanoencapsulation of golpar extract, particle size, and zeta potential was investigated as responses of RSM. The optimal formulation for nanoencapsulation of golpar extract were SO: 50.46%, GE 9.52%, and EM: 36.30% in LSG, SO: 57.07%, GE: 7.12%, and EM: 30.85% in LSG:WPC, and SO: 54.98%, GE: 9.05%, and EM: 39.87% in WPC coating. In conclusion, the nanoencapsulation of golpar extract prepared with the optimized formulation by RSM ensures the gradual release and sedimentation during storage with nanometric size and high yield of encapsulation. The nanocapsules of golpar extract can be used as a natural antioxidant in food systems.
Current research on wax-based oleogels indicates wax esters to be the key component in many natural waxes. This necessitates understanding the properties of pure wax esters to unravel the gelling mechanism in wax-based oleogels. Therefore, wax esters with different carbon numbers and symmetries were studied and characterized regarding their thermal (DSC) and viscoelastic (oscillatory rheology) behavior. Pure wax esters and binary mixtures of wax esters were studied as such and in oleogels formed in combination with medium chained triglyceride oil at WE-inclusion levels of 10 % (w/w). Interpretation of the observations was based on detailed analysis of pre-existing data on crystallographic (SAXS) and thermal properties. It is found that all observations concerning single pure WE’s obey a systematic framework linking molecular make up, crystal structure and behavior. The study on the gelling of four different binary mixtures of wax esters revealed that substantial chain length differences do have the expected consequence of separate crystallization. Mixtures of wax esters with only limited chain length difference reconfirmed earlier speculations on mixing and crystal structure. Applying mixtures of wax esters only differing in their position of the ester bond indicated ideal mixing behavior in the solid phase of the gels. Actually, the data revealed that despite these expected observations in both systems, additional thermal events occur at specific mixing ratios. Their supposed relation to compound formation certainly needs further confirmation. Rheological analysis confirmed that sequential crystallization results in highest firmness values for the systems studied.
Previous studies reported that several amino acids had strong antioxidant activity in vegetable oils under frying conditions. In this study, the carboxylic acid group of amino acids was converted to a carboxylate group (-COO-Na+ or -COO-K+), a heating study was conducted with amino acid salts in soybean oil at 180 ºC. Sodium salts of amino acids including alanine, phenylalanine, and proline and disodium glutamate had significantly stronger antioxidant activity than the corresponding amino acids, and potassium salts had stronger antioxidant activity than sodium salts. Potassium salts of alanine and phenylalanine more effectively retained tocopherols in soybean oil than the corresponding amino acids during heating. Phenylalanine potassium salt had stronger antioxidant activity than phenylalanine in other vegetable oils including olive, high oleic soybean, canola, avocado, and corn oils. Phenylalanine potassium salt at 5.5. mM more effectively prevented oil oxidation than tert-butyl hydroquinone (TBHQ), a synthetic antioxidant, at its legal concentration limit (0.02%) indicating its feasibility as a new antioxidant for frying.
Globally, there is an increasing demand for sources of plant-based protein. While Brassica napus L. is an important oilseed crop worldwide, there is also interest in improving its ability to serve as a valuable source of plant-based protein. Cruciferin, a seed storage protein that makes up 60% of the protein found in mature seeds of B. napus, is of interest for human consumption as a source of protein and as an ingredient in food products due to its functional properties. Existing methods for quantification of cruciferin protein are often time consuming and destroy the seed. This study explored the potential for the measurement of cruciferin protein content in whole seeds of B. napus by near-infrared spectroscopy (NIRS), to allow for efficient and non-destructive screening of breeding material. An enzyme-linked immunosorbent assay (ELISA)-based reference method was utilized to assess cruciferin content in a diverse population of B. napus. Scanning of whole seed samples produced spectra that were used to develop NIRS calibration equations. Statistical analysis of the calibration results indicated that the NIRS equations developed are poorly suited for prediction of cruciferin content.
Monoacylglycerol (MAG) and diacylglycerol (DAG) are two natural components found in most edible oils and fats. Conventional synthesis of MAG and DAG is usually conducted by glycerolysis of triacylglycerol (TAG) at high temperatures (above 200 °C) in the presence of an alkaline catalyst. In this work, the synthesis of MAG and DAG using enzymatic glycerolysis of olive oil was investigated using Tween 80 as surfactant, n-butanol as co-surfactant and the novel lipase in free/liquid formulation Lipozyme TL 100L as catalyst. Experimental design was used to evaluate the effect of enzyme load and reaction temperature on the feedstock conversion. Enzyme load and system temperature were significant variables in the statistical design and the best condition was found at 35 °C, 7.5 vol% of Lipozyme TL 100 and glycerol to oil molar ratio of 2:1 with conversion of TAG at approximately 98 % after 2 h of process. A mathematical model based on the Ping-Pong Bi-Bi mechanism was used to describe the reaction kinetics. The model adequately described the behavior of the system and can be a useful tool for the design of reactors in larger scales.
Enriching foods with long-chain (LC) n-3 polyunsaturated fatty acids (PUFAs) requires a delivery emulsion system, which is both thermodynamically and oxidatively stable. The antioxidant and stabilizing properties of three types of polysaccharide extracts from brown algae Saccharina latissima with mixed composition of polysaccharides (SA: 98% Sodium alginate, SF: 90% alginate and 9% fucoidan, SL: 14.5% fucoidan, 9.5% laminarin and co-extracted non-polysaccharides) were evaluated. SA, SF, SL and REF (added commercial sodium alginate) all showed in vitro ferrous ion chelating ability in the order: SA(99%)>SL(78%)>REF(31%)>SF(16%). The difference in antioxidant activity between SA, REF and SF appeared related to structural differences of alginate (M/G ratio). A storage trial was conducted using 70% (w/w) fish oil-in-water delivery emulsions added sodium caseinate (NaCas) (0.23 wt%) as emulsifier in combination with SA, SF, SL or commercial NaAlg (REF) in different concentrations (C1=0.1, C2=0.2 C3=0.3 and C4=0.4 wt%). A control with only NaCas were included (CON). The physical (e.g. creaming and droplet-size distribution) and oxidative (peroxide value and volatiles) stability of the emulsions, were evaluated (12 days, dark at 20˚C). Acceptable physical stability (creaming index, CI) was found for, REF (all concentrations), SF=0.2 wt% (C2), SL and SA=0.3 wt% (C3) and 0.4 wt% (C4). In general, the oxidative stability decreased by adding REF, SA and SF (except for REF at C1), as prooxidant activity was observed. However, SA showed antioxidant activity against formation of 2-ethylfuran. SL showed antioxidant activity in decreasing formation of volatile compounds in emulsions when added in concentrations above 0.2 wt%.
Cannabinoids biosynthesis in phytoplankton has attracted much attention due to the rapid development of genetic tools and the optimization of genetic transformation methods in microalgae. To monitor the biosynthesis process, proper sample preparation and practical instrumental methods are needed to measure the various precursors, intermediates, cannabinoids, and their degradation products. The objective of this study was to develop a sample preparation procedure for the quantification of olivetolic acid (OA), cannabigerolic acid (CBGA), cannabidiolic acid (CBDA), tetrahydrocannabinolic acid (THCA), olivetol (OL), cannabidiol (CBD), and tetrahydrocannabinol (THC) using single-quadrupole gas chromatography-mass spectrometry (GC-MS). Isochrysis galbana was used as the model matrix. After methanol extraction, samples were purified using solid phase extraction (SPE), silylated with N-methyl-N-(trimethylsilyl)trifluoroacetamide, and analyzed using GC-MS in electron ionization mode. A strong anion-exchange SPE efficiently recovered OA, CBGA, CBDA, and THCA. A graphitized carbon black SPE was necessary to purify OL, CBD, and THC. Both columns removed amino acids, sugars, polyols, and pigments from the algae extract and prepared samples that are suitable for silylation and GC-MS analysis. The total protocol, including solvent extraction, SPE, silylation, and GC-MS analysis, was validated in accordance with the ICH guidelines. Performance characteristics of our method are superior to existing protocols with similar complexity in the literature.
Oil bodies (OBs) are micron- or submicron-sized sub-organelles widely found in plants seeds and nuts. The structure OBs is composed of a core of triglycerides covered by a phospholipid-protein layer, which ensures the stability of the OBs under extreme environmental conditions and further protects core lipids as energy reserves. As naturally pre-emulsified oil-in-water emulsions, OBs have been gradually applied to replace synthetically engineered oil droplets. In this paper, the recent research on the composition, extraction, stability, delivery system, digestion, food applications and future perspectives of plant OBs are reviewed. Recent studies have focused on the OBs surface protein identification and function, large-scale extraction techniques such as enzyme assisted, high pressure, ultrasound, and extrusion and the reconstituted OBs. Electrostatic deposition of polysaccharides significantly improves the stability of OBs emulsions. OBs emulsions have promising applications to encapsulate bioactive compounds, deliver targeted drugs, and prepare gels and edible functional films. The digestive behavior of OBs emulsions is similar to that of protein-stabilized emulsions, which can increase the satiety, effectively help reduce calorie intake and improve the bioavailability of functional factors. It has also promoted the development of simulated dairy, spices and meat products.
An international robin round was carried out to validate a method for the quantification of 2-monochloropropane-1,3-diol (2-MCPD), 3-monochloropropane-1,2-diol (3-MCPD) and 2,3-epoxy-1-propanol (Glycidol) being present as fatty acid esters in plant-based food emulsifiers. The evaluated method was a modification of the American Oil Chemist´s Society (AOCS) Official Method Cd29b-13. Briefly, this method consists from parallel analysis of two sample aliquots that are spiked with different sets of internal standards. Mild alkaline interesterification overnight in the freezer releases the core analytes. Reaction stop and glycidol conversion into monobromopropanediol (MBPD) is realised by addition of acidified sodium bromide solution. Subsequently, matrix removal and analyte extraction are achieved by two liquid/liquid (l/l) extraction steps. After derivatisation with phenylboronic acid (PBA) the final extracts are analysed by gas chromatography-mass spectrometry (GC-MS). Quantification is carried out by internal one-point-calibration. 6 laboratories from 4 European countries participated in the trial and reported 8 data sets for 10 test materials (mono- and diacylglycerides as well as polyglycerol polyricinoleates) that were analysed as blind duplicates, giving a total of 20 samples. Result outliers were eliminated according to accepted standards. At 2-MCPD levels above 0.02 mg/kg, 3-MCPD levels above 0.06 mg/kg and glycidol levels above 0.22 mg/kg repeatability (RSDr) ranged from 1.5 % to 24.9 %, reproducibility (RSDR) ranged from 7.8 % to 29.0 % and HORRATR-values ranged from 0.5 to 1.7. The tested method showed to be suitable for the determination of 2-MCPD, 3-MCPD and glycidol in food emulsifiers consisting from mono- and diacylglycerides as well as polyglycerol polyricinoleates.
In this study, it was investigated to increase the lipid yield of the microalgae Schizochytrium sp., by applying different cell disruption methods. Therefore, acid treatment with HCl, osmotic shock, enzyme applications and ultrasonic homogenizer were tried in this algae species combined with the Bligh and Dyer and Soxhlet methods as an alternative to classical lipid extraction methods. As a result of the study, the highest lipid value (21.72 ± 0.74%) was obtained in enzyme application with Bligh and Dyer method (BDE). The cell disruption processes increased the lipid yield compared to the control groups. The highest PUFA DHA was found in the range of 4.58 ± 2.44-19.25 ± 0.09%, and the highest value was observed in the BDE group. Highest SFA was palmitic acid. Effective results were observed in the Bligh and Dyer applied groups in terms of both total lipid and total fatty acids. In cell disruption methods, particularly in enzyme and HCl extraction, good results were obtained in terms of fatty acids. The highest total fatty acids and the highest lipid content were detected in the Bligh and Dyer enzyme (BDE). Enzyme applications are also advantageous because of being environmentally friendly. Lipid health indices such as n-6/n-3, PUFA/SFA, Atherogenicity index (AI), Thrombogenicity index (TI) and hypocholesterolemic/hypercholesterolemic ratios (HH) were almost favorable. With this study, an appropriate lipid extraction methods were determined to provide an economical and environmental friendly suggestion for future studies to be used in areas such as food, feed and cosmetics.
In 1990, a well-known model to predict pure component properties of triglycerides was presented by Wesdorp in “Liquid-multiple solid phase equilibria in fats: theory and experiments” and has been shown to perform well despite making thermodynamically inconsistent predictions for certain test cases. In this study, the underlying parameter set is improved to deliver more physically consistent predictions, i.e., increasing melting point and enthalpy of fusion with increasing stability of the polymorphs, without deterioration of the primary model quality to describe the available experimental data. Interestingly, when a curated dataset containing only thermodynamically consistent data is compared to a broader dataset, it appears that the model’s efficacy is highly dependent on the quantity of data, specifically the number of unsaturated triglycerides data. Quality and thermodynamic consistency of model predictions and the condition of a reliable description of monoacid triglycerides as a subset is discussed, addressing a potential interdependence.
The utilization and popularization of biodiesel are always limited by its poor cold flow properties. Both bio-based alcohol and diesel from direct coal liquefaction (DDCL) has potential to enhance the cold flow properties of biodiesel. Ternary blends of waste cooking oil biodiesel (BWCO) with DDCL and bio-based ethanol (ET) or 1-butanol (BT) for improving the cold flow properties of biodiesel. The pour point (PP), cold filter plugging point (CFPP), and cloud point (CP) of BWCO-ET, BWCO-BT, and BWCO-DDCL binary blends, and BWCO-ET-DDCL and BWCO-BT-DDCL ternary blends were comparatively assessed. Ternary phase diagrams were also applied into analyze the blending effect of the three components on the cold flow properties of biodiesel. Results showed that both DDCL, ET and BT can remarkably enhance the cold flow properties of BWCO. BT and DDCL presented a better synergistic depression effect. For ternary blends in 20:10:70 blending ratio, BWCO-BT-DDCL exhibited the lowest PP, CFPP, and CP of −23 °C, −19 °C, and −17 °C, respectively. The crystallization behavior and crystal morphology of blended fuels are also observed via a polarizing optical microscope, and find that DDCL together with BT in biodiesel can effectively retard the aggregation of large crystals and inhibit crystals growth.
De-oiled canola meals are sources of protein-containing flavor-active phenolic compounds. Conventional canola oil processing utilizes an excess amount of solvents and is associated with the release of high-intensity bitter flavor-active phenolic compounds, limiting the use of the canola meal. Recent advances in the extraction and isolation of the bitter favor-active phenolic compounds from canola by-products produce protein isolates, however, would benefit the industry by producing a side-stream ingredient rich in phenolics. High temperature and pressure-aided processing, namely the accelerated solvent extraction (ASE) was investigated to extract the flavor-active bitter molecules from the canola meal. The extractability of flavor-active phenolic compounds including the major sinapates, kaempferol derivatives, and other thermo-generative compounds including thomasidioc acid (TA) was evaluated. The effects of temperature, solvent extractant and concentration, and the particle size of the meal, were examined on the extraction efficiency of these phenolic compounds. Extraction temperature (180oC) was the primary determinant (p<0.05) for the attenuation of major sinapates including sinapine and sinapic acid. Both ethanol and methanol extractants at a concentration of 70% (v/v) significantly (p<0.05) extracted the flavor-active phenolic compounds. The pressurized high temperature through optimized ASE conditions attenuated the bitter undesirable flavor-active phenolic molecules from canola meal thereby facilitating a potential value-added phenolic-rich by-product.
Oleosins are mandatory to avoid coalescence of oil bodies (OBs), so commercial proteases are used to efficiently demulsify OBs into food oil. However, the commercial proteases and pH regulators (acid and alkali) greatly restrict this method in industry. In this study, aspartic endopeptidases, subtilisin-like proteases, metalloendopeptidase, and serine carboxypeptidases were identified in isolated sesame OBs by liquid chromatography tandem mass spectrometry (LC–MS/MS). Tricine–sodium dodecyl sulfate–polyacrylamide gel electrophoresis and protease inhibitor assay revealed that aspartic endopeptidases exerted high activity against oleosins in a pH range of 3−6 and a temperature range of 40−70 °C, while subtilisin-like proteases exhibited sharp optimum at pH 5. Metalloendopeptidase contributed to the low activity against oleosins at pH 7−9. Trichloroacetic acid–nitrogen soluble index and free amino acid analyses quantitatively revealed that the activity of serine carboxypeptidases was high at pH 3−5, and optimal at pH 4; the combined activity of aspartic endopeptidases and subtilisin-like proteases was optimal at pH 5. By incubating the isolated sesame OBs at pH 5 and 60 °C for 2 h, approximately 97% of total lipids were recovered as free oil. At last, LC−MS/MS analysis gave deep insight into the intrinsic proteins of sesame OBs: three kinds of oleosins with molecular weights around 17 kDa, and four kinds around 15 kDa; besides 27 kDa caleosin, four kinds of oil body-associated proteins and one kind of peroxygenase-like protein also around 27 kDa; in addition to 39 kDa steroleosin, 11-beta-hydroxysteroid dehydrogenase-like 6 also around 39 kDa.
The first part of this study showed that the triglyceride composition of purified oils has little impact on sterol/sterol ester oleogels. Hence, changes in the gels’ properties observed in previous studies must arise from minor polar components, particularly by changing the interactions within the fibrillar network. Selected molecules (oleic acid, tocopheryl acetate, monoglycerides, and water) were added to three purified oils to unravel the individual contributions introduced by different functional groups. While all additives retarded the molecular self-assembly of sitosterol with oryzanol, distinct effects were found for gel hardness, transition temperatures and enthalpies, strain sweep responses, and microstructure. It was discovered that the maximum storage modulus in the linear viscoelastic region does not necessarily relate to the gels’ compression firmness. In samples comprising oleic acid and tocopheryl acetate, discrete interaction mechanisms with the scaffolding elements were suggested since results between the two additives developed differently and were dose-dependent. A network supporting effect was suggested at low concentrations, in line with previous results for oils comprising low levels of thermal deterioration products. The microstructure of oleogels was considerably modified with additives. Unfortunately, effects are difficult to quantify due to the packed surface observed in AFM micrographs.
The role of solvent composition, in particular, minor oil components on sterol/sterol ester oleogels, has been studied recently . Reportedly, deterioration products hamper network formation and modify the gel’s macroscopic properties, probably due to alterations of the scaffolding elements’ interactions. However, the role of the FA composition of TAGs has not yet been addressed. In this study, minor oil components of three vegetable oils with varying degrees of unsaturation (iodine values) were removed, and the oils were chemically and physically characterized before and after the treatment. Consequently, β sitostero/γ-oryzanol oleogels were produced, and the gel-sol (DSC) and sol-gel (rheology) transitions were monitored. Moreover, large and small deformation tests were performed, and the results were linked to oil parameters. In contrast to minor oil components, the FA composition has little impact on oleogel properties. The decline in gel hardness with IV is possibly linked to a lower solvent viscosity. However, a considerable drop in gel-sol transition temperature was observed with increasing IV indicating fewer elements of scaffolding. That was linked to the rapid formation of primary oxidation products in purified flaxseed oil during oleogel preparation, impairing tube formation. Similar to previous results on deterioration products, these minor components seem to aid network strength at low concentrations resulting in similar transition enthalpies and G’. That might be due to shifted network interactions in the presence of molecular species with functional groups. In the second part of this study, these modified interactions in the presence of selected minor components will be discussed.