Seeds of Lithospermum officinale L. from different climatic zones were analyzed looking for new sources γ-linolenic acid (GLA, 18:3n-6) and stearidonic acid (SDA, 18:4n-3). Cultured B. officinalis was also analyzed with comparative purposes. Analyses were conducted for fatty acid (FA) profiles in the whole seeds and in the neutral and polar lipids by GC; lipid classes by open column chromatography and preparative TLC; and tocopherols, sterols and phenolic compounds by HPLC-DAD, and the later compounds were confirmed by LC-MS. The richest GLA sample was L. officinale from St. Petersburg Botanical Garden (17.9% of total FA), while wild-growing L. officinale from the Rostov region showed the highest percentage of SDA (17.2% of total FA). Total FA content ranged from 11.3 to 20.8% of seed weight. Neutral and polar lipids accounted for ~98 and 2.27% of total lipids. Five neutral lipid classes were identified (% of NL): triterpene esters, 1.3; triacylglycerols, 93.1; free FA, 1.8; diacylglycerols, 1.4; and monoacylglycerols, 2.4. Tocopherols and sterols reached 35.7 and 83.8 mg/100 g seeds; γ-tocopherol was the main tocopherol detected, and Δ5-avenasterol was the predominant sterol. L. officinale seeds contain high amounts of phenolic compounds (389.9 mg/100 g as upper limit), in which rosmarinic acid was the main component. Overall, all data suggest the possibility of using L. officinale seed oil in pharmaceutical and cosmetic formulae and as functional food.
Poor cold flow property is a major issue that hinders the application of biodiesel-diesel blends. In this work, a series of methacrylate-benzyl methacrylate-N-vinyl-2-pyrrolidone terpolymers (RMC-MB-NVP, R= C12, C14, C16, C18) was synthesized and used as the pour point depressants (PPDs) for waste cooking oil biodiesel blends. To further improve their depressive effects, dispersants, including Tween (40, 60, and 80), Span (40, 60, and 80), phthalic acid esters (PAEs), and fatty alcohol polyoxyethylene ether (FAPE; FAPE 5, FAPE 7, and FAPE 9), were optimized and combined with the C14MC-MB-NVP terpolymers. The effects of C14MC-MB-NVP terpolymers and combined PPDs (PPDC) on the cloud point (CP), cold filter-plugging point (CFPP), and pour point (PP) of biodiesel blends were studied. Here, results showed that the presence of dispersants can efficiently enhance the solubility and dispersibility of polymeric PPDs in biodiesel blends; thus, the PPDC presents better depressive effects. Among of them, C16MC-MB-NVP (5:1:1) combined with FAPE 7 dispersant at 4:1 mass ratio (PPDC-FAPE 7) showed the best synergistic effect, and the CP, CFPP, and PP of B20 treated with 2000 ppm PPDC-FAPE 7 decreased by 4, 10 and 19 °C, respectively. Moreover, differential scanning calorimetry, polarizing optical microscope and rheological analyses were performed to rationalize the action mechanism of these PPDs and dispersants in biodiesel blends.
The food industry is seeking natural antioxidants for edible oils that have comparable activity to synthetic counterparts. In this study, Osage orange extract (OOE) rich in osajin (42.9%) and pomiferin (30.0%) was obtained after hexane extraction of the fruit, and its antioxidant activity was examined in stripped soybean oil (SBO) and fish oil (FO), in which antioxidants and polar compounds were removed. The antioxidant activity of OOE was compared with commercial natural antioxidants (i.e., rosemary extract and mixed tocopherols) and a synthetic antioxidant, butylated hydroxytoluene (BHT), during storage at 25 and 40 ℃. The 0.1% OOE had stronger antioxidant activity than 0.1% rosemary extract and 0.1% mixed tocopherols in both oils at 25 and 40 ℃. Its activity was similar to 0.02% BHT in SBO and was similar or slightly stronger than 0.02% BHT in FO. When OOE was studied at 0.05, 0.1, and 0.2%, there was a weak dose-response in SBO but a stronger dose-response in FO. Headspace volatile analysis using solid phase micro-extraction (SPME) combined with GC-MS indicated that 0.1% OOE was very effective in preventing the formation of volatile oxidation products in both oils. Although it should be further tested for safety before the actual use, this study shows that OOE can be developed as an antioxidant for edible oils.
Epoxidized methyl esters (EMO) with their high oxirane ring reactivity, acts as a raw material in the synthesis of various industrial chemicals including polymers, stabilizers, plasticizers, glycols, polyols, carbonyl compounds, biolubricants etc. EMO has been generally quantified by the gas chromatography (GC) and high performance liquid chromatography (HPLC) techniques. Taking into the account of the limitations of these techniques, two qHNMR based equations have been proposed for the quantification of EMO in the mixture of EMO and methyl esters (MO). The validity of the proposed method was determined using standard mixtures of MO and EMO having different molar concentrations. The developed equations have been applied on the samples of EMO prepared from oleic acid in two step process viz., esterification followed by epoxidation. The qHNMR based EMO quantification showed acceptable agreement with the results obtained from HPLC analysis.
This work presents an original approach to develop an integrated process to improve the nutritional characteristics of natural oils, starting with the extraction from the raw material by environmentally friendly methods and following with the production of novel acylglycerols using immobilized lipases. Specifically, 2-monoacylglycerols (2-MAGs) enriched in the omega-3 stearidonic acid (SDA) were synthesized by selective ethanolysis of extracted Echium plantagineum oil using the lipase from Thermomyces lanuginosus (TLL). Different reaction conditions were investigated to minimize the undesirable acyl migration and to ensure the purity of final products. The biocatalyst produced in our laboratory by the immobilization of TLL on a hydrophobic support reached the maximum theoretical amount of 2-MAG in only 2 h at mild reaction conditions, achieving a product enriched in omega 3 SDA (up to 25%). Moreover, the produced biocatalyst exhibited higher stability than commercial lipases. The average activity after 5 cycles was 71%, allowing several reutilization cycles and developing a feasible enzymatic process. Finally, 2-MAGs was used as starting material to synthesize structured triacyclglycerols (STAGs) in solvent-free systems. The use of molecular sieves in combination with the immobilized lipase from Rhizomucor miehei (RML) showed to be an extraordinarily fast strategy to produce pure STAGs (100% in 1h), 4 times higher than the activity showed by the commercial derivative. Thus, the enzymatic processes developed in this study open a range of possibilities to synthesize omega-3 acylglycerols with improved characteristics for essential biological functions and nutritional advantages, proving the usefulness of immobilized lipases to produce novel functional lipid.
The application of nanostructured lipid carrier (NLC) in UV filters encapsulation was found to enhance its safe use. In this work, kenaf seed oil-NLC (KSO-NLC) co-loaded with UV filters encapsulated was used as an active ingredient in α-tocopherol cream to develop a photoprotective prototype. It was then subjected to further analysis to determine the physical properties storage stability and cytotoxicity. The ratio of KSO-NLC to α-tocopherol cream was optimised based on the SPF value using UV transmittance analyser. The physical properties of the samples were analysed and the amount of α-tocopherol was quantified by ultra-high performance liquid chromatography (UHPLC). The optimised sample was then evaluated for in vitro antioxidant activities using DPPH and ABTS assays. Meanwhile, in vitro cytotoxicity was studied on normal human dermal fibroblast (NHDF) cell line using MTT and CCK-8 assays. The sample produced by KSO-NLC to α-tocopherol cream in ratio 1:2 (N3) showed SPF value > 50. Besides, the samples showed microbial stability and sustainable α-tocopherol content upon 12 weeks of storage. The cytotoxicity evaluation of N3 and α-tocopherol cream (N5) showed > 100 % cell proliferation indicated there is no side effect on the cell growth, yet it triggered the cell proliferation with the presence of bioactive compounds. Overall, the results herein gathered are very promising towards the development of new green cosmetic formulations with the utilisation of KSO-NLC and palm-based α-tocopherol cream.
Oleogels prepared from hydrocolloids have recently gained a lot of attention as an alternative for trans and saturated fats. Previously we have demonstrated that the freeze-dried foams prepared using a mixture of 5% faba bean or pea protein concentrates with 0.25% xanthan gum at pH 7 and 9 can hold canola oil 30-40 times their weights (Mohanan, Tang, Nickerson and Ghosh, 2020). However, the oleogels suffered from high oil loss, about 30% oil leaked, which negatively affected the rheological properties of the oleogels. The functionality of the cake baked using the oleogels was poorer compared to a shortening baked cake. The present study explored the addition of a small amount of high-melting monoacylglycerol (MAG) and candelilla wax (CW) on reducing oil loss, improving rheological properties and baking qualities of pulse protein-stabilized oleogels. Different concentrations (0.5-3%) of MAG or CW were dissolved in canola oil at 80 ºC. The hot oil was then added into the freeze-dried protein-polysaccharide foams (pH 7) and quickly transferred to a refrigerator. The crystallized additives reinforced the oleogel network, thereby reducing oil loss while increasing the firmness, cohesiveness, and storage modulus. When model cakes were baked with the oleogels, significant improvement in textural properties was observed with the addition of MAG in the foam-templated oleogels. However, in comparison with shortening-based cakes, oleogel-based cakes still showed a negative effect on hardness, chewiness and cohesiveness.
High voltage atmospheric cold plasma (HVACP) treatment generates reactive gas species that induce inter and intramolecular reactions in soybean oil. The goal of this study is to analyze the effect of HVACP treatment on the chemical structure of soybean oil in a hydrogen gas environment at atmospheric pressure. HVACP was used to treat soybean oil (15g), for up to 6h by triplicate. Plasma generated reactive gas species interact with the sample producing three distinct fractions identified as a liquid, gel, and solid. Fatty acid profile, FTIR, 1H-NMR/13C-NMR, GPC, thermal properties and peroxide value, were used to characterize the chemical structure. Results indicated a lower content of polyunsaturated fatty acids, increased content of saturated fatty acids, and the presence of isomers. An insoluble portion was observed in the solid fraction and increase with treatment time up to 42% in the 6h treated samples. Plasma species may cause two main reactions: polymerization and hydrogenation.
In the present study, green tea extract was encapsulated in liposomes prepared by Mozafari method (without any organic solvents) and characterized for its physicochemical properties e.g. encapsulation efficiency, particle size and z- potential. The obtained results for encapsulation efficiency, particles size and z- potential were 51.34, 419 nm and -57 mV, respectively. Total polyphenol content of green tea was obtained 164.2 mg gallic acid /g extract. Free radical scavenging activities of free and liposomal extract, with using DPPH method were measured 90.6% and 93.37% respectively. Antioxidant activity of ethanolic extract of green tea in free and liposomal form were measured at concentration of 200, 600 and 1000 mg/L on the oxidative stability of canola oil during 60°C temperature for 0, 4, 8, 12, 16, 20, 24, 28 and 32 days. The results compared with synthetic antioxidant butylated hydroxytoluene at 200 mg/L. To evaluate antioxidant activity on canola oil stability, peroxide value, Thiobarbitoric acid, anisidine value, TOTOX and rancimat test measured. Results showed that liposomal green tea extract acted more effective than free extracts. Also, 600 mg/L concentration of green tea extract showed significant antioxidant activity in compare to others. The increasing storage time and different concentrations of ethanolic green tea extracts had significant effects on canola oil stability (P≤0.05). The obtained results showed green tea extract could act as an effective antioxidant. Green tea extract in free and liposomal form at 600 mg/L concentration resulted stronger function than butylated hydroxytoluene synthetic antioxidant.
Glycerol can be effectively converted to glyceric acid, a high value-added pharmaceutical raw material, through its partial oxidation over an Au catalyst under strongly basic conditions. The factors important for the highly selective production of glyceric acid were investigated experimentally. It was clarified that NaOH was involved in the glycerol activation step to a glycerol alkoxide intermediate in the liquid phase, then glyceric acid was formed by OOH species derived from O2 on an Au catalyst in the partial oxidation step. We have newly discovered the concerted effect of NaOH and O2 in different reaction steps.
American Oil Chemists’ Society (AOCS)’s Official Method Cd 18-90 for p-Anisidine Value (pAV) is commonly used to evaluate secondary oxidation in fish oils. Flavoring agents in fish oil products may interfere with pAV and lead to inaccurate results. The Global Organization for EPA and DHA (GOED) recommends a protocol for calculating pAV of flavored fish oils, based on the assumption that flavors’ contribution to the pAV does not change over the course of oxidation. The objective of this study was to test this assumption. All fourteen flavors evaluated increased the pAV when added to fresh fish oil; chocolate-vanilla and lemon flavors generated the largest increase. Under accelerated oxidation conditions, both chocolate-vanilla and lemon flavors had a similar effect; oxidized flavored fish oils had lower pAV than oxidized fish oils with newly added flavors. This was due to either an antioxidant effect of the flavor or degradation of the flavor during oxidation. Following the GOED recommendation, we would have underestimated the oxidation in the flavored oils. For this reason, pAV of flavored fish oils should be considered with caution and used in combination with other secondary oxidation markers when possible.
The crystallization behavior of mango kernel fat (MKF) at 25 °C with and without the application of high-intensity ultrasound (HIU) (20 kHz, 125 W) was studied as a function of ultrasound amplitude level (30%, 50% and 70% of the maximum amplitude of 180 μm). The irradiation time was fixed at 5 s. It was found that HIU induced MKF crystallization. The crystallization induction time decreased with a decrease in crystal size and an increase in the number of crystals as the HIU amplitude increased. The β′→β transformation was also accelerated with HIU application. This work has shown that there is a great potential for the use of HIU in the food industry to achieve a shorter and more controllable crystallization process. In particular, HIU could be used as an efficient tool for controlling the polymorphic transition of fats.
The goal of the present study is to demonstrate 1H LF-NMR time relaxation measurements for efficient and rapid evaluation of Omega-3 polyunsaturated fatty acids (PUFA)-rich linseed oil (LSO) oxidative aging mechanisms, by monitoring primary chemical and structural changes occurring during thermal oxidative stress. The LF NMR monitors the different proton spin-spin coupling energy relaxation times, T2 within LSO molecular segments, from the initiation of free radical generation and hydroperoxide formation to the propagation of alkoxy radicals, and alpha, beta-unsaturated aldehydes formation, and a termination phase of crosslinked polymerization end products. The 1H LF NMR T2 values monitors both the covalent and secondary bonding interactions (e.g., electrostatic and hydrogen bonding) during the different oxidation phases. The present paper shows that LSO tail segments mobility in terms of T2 multi-exponential relaxation decays, generated by data reconstructing of 1H transversal relaxation components are providing a clear, sharp and informative understanding of LSO sample’s autoxidation aging processes. This is supported by high field band selective 1H NMR pulse excitation for hydroperoxide and aldehydes quantification of the same LSO samples at 25, 40, 60, 80, 100, and 120oC with pumped air for 168 h. Peroxide value, viscosity and self-diffusion, as well as fatty acids profile and by- products determined by GC-MS were also carried out, and correlated with the LSO tail T2 relaxation results. In conclusion the selective determination of LSO alkyl tail T2 energy relaxation time domain values was demonstrated as a rapid evaluation marker for following omega-3 PUFA-rich oils oxidative aging.
Quantitative analyses on the coefficient of friction of common coating waxes are necessary and essential for designing systems for coating, conveying, packaging operations, transporting and storing of papers and paperboards, while analyses on wear behavior can be helpful for predicting performance durability of the coating surface. In this study, we investigated the friction and wear behaviors of six waxes including four commercial waxes and two soybean oil-based wax developed in our lab for bulk coating on cardboard. The effect of normal load, sliding velocity, and environmental temperature was evaluated. The friction coefficient of different waxes varies with sliding conditions. Higher normal load, sliding velocity, and environmental temperature resulted in significantly greater wear loss. Crystalline morphology and crystallinity were affected by environmental temperature, and they correlate to the variations in friction coefficient and wear loss of these materials. Overall, the Estercoat developed in our lab had comparable frictional properties and much less wear than paraffin wax under tested conditions and can be a good substitute for paraffin wax.