Extraction and Characterization of Flaxseed Oil Obtained with Subcritical n-Butane.

In this study, subcritical n-butane was adopted to extract oil from flaxseed. The extraction conditions i.e. extraction temperature, extraction time, and liquid-solid ratio were investigated and optimized by response surface methodology. The flaxseed oil obtained by subcritical n-butane were characterized and compared with those prepared by n-hexane and cold pressing. Results indicated that the optimal combination of parameters was 53.93℃, 56.82 min, and 19.98:1 mL/g. Subcritical n-butane had higher yield (28.75%) than n-hexane and cold pressing. GC analysis indicated that subcritical n-butane extraction had no obvious influence on the fatty acid composition. Nevertheless, the oil obtained by subcritical n-butane with higher contents of phytosterols (2.93 mg/g) and carotenoids (46.56 mg/kg), and presented a higher oxidation stability (9.27 h). Thus, it was suggested that subcritical n-butane extraction is a promising alternative to extract high quality flaxseed oil.

Effect of infrared-assisted spouted bed drying of flaxseed on the quality characteristics of its oil extracted by different methods.

BACKGROUND: Infrared (IR)-assisted spouted bed drying (SBD) has emerged as a potential alternative to the traditional hot air drying for heat sensitive components. The aim of this study was to investigate effect of IR-assisted SBD and application of cold press (CP), solvent extraction (SE) and ultrasound assisted extraction (UAE) on the quality of flaxseed oil. SBD and IR-assisted SBD were performed at air temperatures of 40, 60, 80 °C and their effects on the drying rate, fatty acids composition and oil peroxide and acid values were evaluated. Quality of oil extracted from the dried flaxseeds by CP, SE and UAE methods was then evaluated. RESULTS: Increasing air temperature in the presence of IR increased the drying rate. The peroxide values (PVs) of IR-SBD samples were higher than those of SBD at the same temperature. IR treatment did not notably change the composition of fatty acids in flaxseed oil, except in linoleic acid content. UAE gave higher extraction yield than CP and SE methods. UAE yielded an oil with higher percentage of saturated fatty acids, whereas the percentage of omega-3 and omega-6 fatty acids was higher in the CP method. The oil extracted by CP exhibited lower levels of PV (0.516 meq O2 /kg oil) and acid value (1.36%), as compared to oils extracted by SE and UAE methods. CONCLUSION: Both UAE and conventional methods did not significantly influence the composition of fatty acids in the extracted oils. Nonetheless, the CP method yielded an oil with a high percentage of omega-3 and omega-6 fatty acids. © 2019 Society of Chemical Industry.

Extraction of Oil from Flaxseed (Linum usitatissimum L.) Using Enzyme-Assisted Three-Phase Partitioning.

In this study, enzyme-assisted three-phase partitioning (EATPP) was used to extract oil from flaxseed. The whole procedure is composed of two parts: the enzymolysis procedure in which the flaxseed was hydrolyzed using an enzyme solution (the influencing parameters such as the type and concentration of enzyme, temperature, and pH were optimized) and three-phase partitioning (TPP), which was conducted by adding salt and t-butanol to the crude flaxseed slurry, resulting in the extraction of flaxseed oil into alcohol-rich upper phase. The concentration of t-butanol, concentration of salt, and the temperature were optimized to maximize the extraction yield. Under optimized conditions of a 49.29 % t-butanol concentration, 30.43 % ammonium sulfate concentration, and 35 °C extraction temperature, a maximum extraction yield of 71.68 % was obtained. This simple and effective EATPP can be used to achieve high extraction yields and oil quality, and thus, it is potential for large-scale oil production.

The evaluation of the healing proprieties of pumpkin and linseed oils on deep second-degree burns in rats.

CONTEXT: Medicinal plants have been recognized as useful remedies for primary health care. Accordingly, Cucurbita pepo L. (Cucurbitaceae) (pumpkin) and Linum usitatissimum (L.) Griesb. (Linaceae) (linseed) which have extracted oil with prominent pharmacological properties are investigated as possible burn healing treatments. OBJECTIVE: The present study assesses the healing potential of pumpkin and linseed extracted oils on rats. MATERIALS AND METHODS: Uniform deep second-degree burns were induced on the dorsum of 24 rats, randomly divided into four groups. The burns were measured, photographed, and topically treated with saline solution, "Cytol Centella®", pumpkin, and linseed-extracted oils (0.52 µl/mm(2) of oil) each 2 d (up until day 33). Post-burning of the 33rd day, biopsies were histologically assessed. RESULTS: At the end of the experiment, the rat groups treated with linseed, pumpkin oils, and "Cytol Centella®" had higher percentage of wound contraction (98.68, 96.71, and 92.54%, respectively) than the control group (58.38%). Wound biopsies from rats treated with extracted oils showed the best tissue regeneration proprieties as compared with the other groups. The histomorphometric analysis of biopsies revealed that linseed oil could significantly stimulate angiogenesis (55.6% ± 7.25). The pumpkin oil, and Cytol Centella® could significantly increase the collagen production 64.9% ± 5.94, and 61.2% ± 7.36, respectively. DISCUSSION AND CONCLUSION: Overall, our study has given for the first time scientific evidence of the healing efficiency of pumpkin and linseed oils on burn-wounds.

Enhanced Extraction of Oil from Flaxseed (Linum usitatissimum L.) Using Microwave Pre-treatment.

The effect of microwave (MW) pre-treatment on the extraction of flaxseed oil was investigated by hot extraction (HE). Nine MW pre-treatments were established, combining three MW radiation intensities (12, 18 and 24 W/g) and three MW radiation times of pre-treatment (90, 150 and 210 s). Extraction yield increased significantly with MW pre-treatments of flaxseed, and a max oil extraction yield (78.11%) can be obtained using MW pre-treatment at 18 W/g for 210 s. Scanning electronic microscopy showed that the microstructure of treated samples (18 W/g and 210 s) was modified compared with that of untreated samples. The fatty acid compositions (palmitic acid 5.85±0.01%, stearic acid 3.00±0.01%, oleic acid 17.64±0.07%, linoleic acid 16.16±0.06%, and linolenic acid 57.37±1.32%) of the oils extracted by the MW pre-treatments HE were similar with that of the conventional HE method. Results showed that fatty acid compositions of flaxseed oil were not affected by MW pre-treatments.

Glycine-containing flaxseed orbitides.

Five new orbitides, cyclolinopeptides 21-25, were identified in flaxseed oil (Linum usitatissimum) extracts. Their HPLC-ESIMS quasimolecular ion peaks at m/z 1097.7 (21), 1115.6 (22), 1131.6 (23), 1018.6 (24), and 1034.6 (25) [M + H](+) corresponded to the molecular formulae C59H89N10O10, C58H87N10O10S, C58H87N10O11S, C53H80N9O9S, and C53H80N9O10S, respectively. Their structures were elucidated by extensive HPLC-ESIMS/MS analyses, and their presence was confirmed by precursor proteins identified in flax genomic DNA sequence data. The amino acid sequences of these orbitides were confirmed as [1-10-NαC]-GILVPPFFLI, [1-10-NαC]-GMLIPPFFVI, [1-10-NαC]-GOLIPPFFVI, [1-9-NαC]-GMLVFPLFI, and [1-9-NαC]-GOLVFPLFI for cyclolinopeptides 21-25, respectively. Previously reported orbitides, [1-9-NαC]-ILVPPFFLI (1), [1-9-NαC]-MLIPPFFVI (2), [1-9-NαC]-OLIPPFFVI (3), [1-8-NαC]-MLVFPLFI (7), and [1-8-NαC]-OLVFPLFI (8), were also present in flaxseed oil. The precursors of orbitides 21, 22, and 24 also produced orbitides 1, 2, and 7 by alternative cyclization. Cyclolinopeptides 3, 8, 23, and 25 contain MetO (O) and are not directly encoded, but are products of post-translational modification of the Met present in 2, 7, 22, and 24, respectively. Sufficient cyclolinopeptide 23 was isolated for characterization via 1D ((1)H and (13)C) and 2D (NOESY and HMBC) NMR spectroscopy. These compounds have been named as cyclolinopeptides U, V, W, X, and Y for 21, 22, 23, 24, and 25, respectively.

Effect of cyclolinopeptides on the oxidative stability of flaxseed oil.

Polar compounds present in flaxseed oil increase its oxidative stability. Flaxseed oil becomes less stable to oxidation when filtered with silica. This observation may be linked to antioxidant compounds present in flaxseed oil. Flaxseed oil was passed over a silica adsorbent column to remove polar compounds. The polar compounds were then eluted from the silica absorbant using a series of increasingly polar solvents. The polar fractions from flaxseed oil were then added back to silica-treated flaxseed oil to determine the impact of fractions containing polar compounds on oxidative stability (induction time) at 100 °C. A polar fraction containing mainly cyclolinopeptide A (CLA, 1), but also containing ß/γ- and δ-tocopherol increased the induction time of silica-treated flaxseed oil from 2.36 ± 0.28 to 3.20 ± 0.41 h. When oxidative stability was determined immediately after addition of the polar fractions other flaxseed fractions and solvent controls did not affect oil stability. However, when the oxidative stability index (OSI) test was delayed for three days and oil samples were held at room temperature after the addition of the polar fractions to the flaxseed oil, it was observed that the control oil treated with silica had become highly sensitive to oxidation. A polar fraction containing a mixture of CLs (1, 5, 7, 9, 11), improved the oxidative stability of peptide-free oil with respect to the control when the OSI measurement was made three days after adding the fraction. In addition, effects of 1 on the oxidative stability of peptide-free oil containing divalent metal cations was investigated.

Ultrasound-assisted extraction of flaxseed oil using immobilized enzymes.

An aqueous enzymatic process assisted by ultrasound extraction (AEP-UE) was applied to the extraction of oil from flaxseed (Linum usitatissimum L.). The highest oil recovery of 68.1% was obtained when ground flaxseed was incubated with 130 U/g of cellulase, pectinase, and hemicellulase for 12h, at 45°C and pH 5.0. The IC(50) values of oil obtained by AEP-UE and organic solvent extraction (OSE), as measured by DPPH scavenging activity essay, were 2.27 mg/mL and 3.31 mg/mL. The AEP-UE-derived oil had a 1.5% higher content of unsaturated fatty acids than the OSE-derived oil. AEP-UE is therefore a promising environmentally friendly method for large-scale preparation of flaxseed oil.

Anti-inflammatory, analgesic and antipyretic activities of Linum usitatissimum L. (flaxseed/linseed) fixed oil.

The fixed oil of L. usitatissimum (flaxseed/linseed) inhibited PGE2-, leukotriene-, histamine- and bradykinin-induced inflammation. The oil also inhibited arachidonic acid-induced inflammation, suggesting its capacity to inhibit both cyclooxygenase and lipoxygenase pathways of arachidonate metabolism. In tail immersion model, the oil raised the pain threshold to a lesser extent than morphine but showed excellent peripherally acting, analgesic activity comparable to aspirin, against acetic acid-induced writhing in mouse. In typhoid paratyphoid A/B vaccine-induced pyrexia, the oil showed antipyretic activity comparable to aspirin. The oil contains 57.38% alpha-linolenic acid. Dual inhibition of arachidonic acid metabolism, antihistaminic and antibradykinin activities of the oil could account for the biological activity and the active principle could be alpha-linolenic acid an omega-3 (18:3, n-3) fatty acid.

Linum usitatissimum (linseed/flaxseed) fixed oil: antimicrobial activity and efficacy in bovine mastitis.

PURPOSE: In vitro antimicrobial activity and in vivo therapeutic efficacy of L. usitatissimum (linseed/flaxseed) fixed oil in bovine mastitis were investigated. METHOD: In vitro antimicrobial activity of L. usitatissimum fixed oil was evaluated against a number of microorganisms by disc diffusion method and MIC determination. The in vivo efficacy of the oil was evaluated in nine mastitis-affected cows divided into three groups (three in each group), following once-a-day intramammary infusion of oil, cefoperazone or an oil-cefoperazone combination for 7 days and by monitoring the California mastitis test score, somatic cell count and microbial count in milk samples. RESULTS: The in vitro antimicrobial activity of the oil against Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli was comparable to that of cefoperazone while the antimicrobial activity against Enterococcus faecalis, Micrococcus luteus and Candida albicans, was greater than that of cefoperazone. In the in vivo study, the oil exhibited significant reduction in the California mastitis test score and somatic cell count in milk samples from infected udders following 7 days of intramammary administration suggesting its anti-inflammatory effect. The microbial count in milk samples was also reduced significantly following oil treatment. The effects were comparable to the treatment by cefoperazone (Mastiwock) alone or in combination with the oil. Apparently, the anti-inflammatory and antimicrobial properties of the oil contribute to its therapeutic efficacy in mastitis; the oil could be used as an alternative treatment for bovine mastitis CONCLUSION: The results suggest possible therapeutic potential of L. usitatissimum fixed oil in bovine mastitis.

[Anti-radical activity and oxidative stability of oils manufactured from flax, sesame and silybum seeds].

Comparative analysis of oils, prepared from flax, sesame and silybum seed composition, and adequate oil blends, prepared by mixing flax oil, sesame oil and silybum oil was performed. Antiradical activity was evaluated for the oils, both for their methanol-soluble phase and the fraction insoluble in methanol. DPPH radical scavenging activity expressed in Trolox equivalent antioxidant capacity. Oxidative stability during 6-month store was evaluated by peroxide value and dienic conjugates content. Oils from seed composition show the more high antiradical activity and oxidative stability than adequate oil blends. A significant correlation was found between antiradical activity and gamma-/alpha-tocopherol ratio in oils.

The application of ultrasound energy to increase lipid extraction throughput of solid matrix samples (flaxseed).

Ultrasound may reduce lipid extraction times and increase analysis throughput of food materials. Ground flaxseed (25mg aliquots) were extracted in quadruplicate in 2:1 (v:v) chloroform:methanol, 3:2 hexane:isopropanol, 1:1 diethyl:petroleum ether or hexane with exposure to sonication at low frequencies of 20kHz with a 600W ultrasonic processor. Power was automatically varied to maintain constant amplitudes of 20%, 60% and 100% of 240microm for sonication exposures for 5, 10 and 20min, respectively. Total lipid dry weights and quantitative and qualitative fatty acids were determined. Results were compared to a standard 24-h, Folch-based, 2:1 chloroform:methanol extraction. Longer time exposures and higher sonication amplitudes were associated with increases in lipid recoveries. In particular, ultrasound-assisted extraction in 3:2 hexane:isopropanol for only 10min resulted in lipid and fatty acid recoveries similar to the 24-h standard method. Comprehensive testing on a variety of sample matrices and food products is required, but lipid extraction by ultrasound has potential to reduce sample processing time.