Rapid screening of antioxidant activity of sage (Salvia officinalis L.) extracts obtained by supercritical carbon dioxide at different extraction conditions

Sage herb (Salvia officinalis L.) was extracted at supercritical fluid extraction (SFE) conditions with carbon dioxide at different parameters and the extracts tested on their antioxidant activity (AA). SFE of sage herb at 35 MPa pressure was found to be an effective method to obtain pure extracts. The yields of the extracts were substantially increased by using 1% of entrainer solvent ethanol. The fractionation of sage extract was a complex procedure in terms of extract distribution between separators operating at various pressure and temperature conditions. It was also proved by testing the AA of the extracts in rapeseed oil. The effect of the extracts on the rapeseed oil weight gain varied in a wide range (from ‘very low’ to ‘high’) depending on the fractionation conditions. Preliminary results showed that to obtain more effective antioxidant fractions separation steps should be started at 10 MPa lower pressure than that used for the extraction.     

Phenolic and antioxidant potential of olive oil mill wastes

Olive oil mill waste was subjected to conventional liquid solvent extraction and supercritical fluid extraction using different solvents and carbon dioxide, respectively. The optimum solvent extraction conditions of phenols were 180 min using ethanol, at a solvent to sample ratio 5:1 v/w, and at pH 2. Solvent and SFE extracts were tested for their antioxidant activity by the DPPH radical scavenging method and by determination of peroxide value on virgin olive oil and sunflower oil. The ethanol extract exhibited the highest antiradical activity, and no correlation was found between antiradical activity and phenol content. The SFE extract exerted good antioxidant capacity although its phenolic yield was not quite high. Moreover, the ethanol extract appeared to be a stronger antioxidant than BHT, ascorbyl palmitate and vitamin E by the Rancimat method on sunflower oil. HPLC analysis of the extracts showed that the predominant phenolic compound was hydroxytyrosol. Various phenolic acids and flavonoids were also identified.     

Antioxidant activity of sage extracts in rapeseed oil irradiated with UV-rays

The antioxidant activities of sage acetone oleoresin and its methanol-water fractions were tested in rapeseed oil at 0.1% concentrations and 80 degrees C temperature after irradiation with UV-rays (exposition 0.5 h). It was determined that even little doses of UV irradiation induce oxidation process in rapeseed oil samples both with additives and without them. The antioxidant activity of a synthetic antioxidant BHT was much lower than that of the sage fractions at 80 degrees C and forced air oven conditions. This finding proves the advantage of sage extracts in comparison with BHT at high temperatures. It was also found that methanol-water fraction separated from acetone oleoresin had the highest antioxidant activity in terms of the formation of primary and secondary oxidation products. Oil sample with this additive had the highest protection factor (PF = 4.53) when the oil was not irradiated with UV rays. The data obtained showed that all sage extracts had very strong antioxidant activity (PF > 3).     

Supercritical fluid extraction and hydrodistillation for the recovery of bioactive compounds from Lavandula viridis L’Hér

The chemical profiles of bioactive essential oil and extracts obtained by hydrodistillation (HD) and supercritical fluid extraction (SFE), respectively, from Lavandula viridis were compared. The SFE was performed at 40 °C and at extraction pressures of 12 or 18 MPa in two different separators. Evaluation of the essential oil and SFE extracts by GC–FID and GC–IT–MS revealed that oxygen-containing monoterpenes were the major constituents in both cases, but there were important differences between the chemical profiles produced by the different extraction techniques. More compounds were isolated by HD but higher yields were achieved by SFE. Camphor was the main component identified in the essential oil (31.59 ± 1.32%), and in extracts from the first (1.61 ± 0.34%) and second SFE separators (22.48 ± 1.49%) at 12 MPa. In contrast, the first separator SFE extract at 18 MPa (heavy compounds) was dominated by myrtenol (5.38 ± 2.04%) and camphor (4.81 ± 1.93%), whereas the second separator SFE extract (volatiles) was dominated by verbenone (13.97 ± 5.27%). The essential oil and heavy compound extracts from the first separator possessed antioxidant and anti-cholinesterase activities. Our data show that phytochemicals from the aerial parts of L. viridis could be developed as natural antioxidant and anti-cholinesterase drugs, with particular applications in the symptomatic treatment of Alzheimer’s disease.     

Antioxidant activity of sage extracts in rapeseed oil irradiated with UV‐rays

The antioxidant activities of sage acetone oleoresin and its methanol‐water fractions were tested in rapeseed oil at 0.1% concentrations and 80°C temperature after irradiation with UV‐rays (exposition 0.5 h). It was determined that even little doses of UV irradiation induce oxidation process in rapeseed oil samples both with additives and without them. The antioxidant activity of a synthetic antioxidant BHT was much lower than that of the sage fractions at 80°C and forced air oven conditions. This finding proves the advantage of sage extracts in comparison with BHT at high temperatures. It was also found that methanol‐water fraction separated from acetone oleoresin had the highest antioxidant activity in terms of the formation of primary and secondary oxidation products. Oil sample with this additive had the highest protection factor (PF = 4.53) when the oil was not irradiated with UV rays. The data obtained showed that all sage extracts had very strong antioxidant activity (PF > 3).     

Preliminary screening of antioxidant activity of some plant extracts in rapeseed oil

The antioxidant activity (AA) of acetone extracts of sage (Salvia officinalis L.), sweet grass (Hierocloë odorata Wahlnb.), sea buckthorn leaves (Hipophaë rhamnoı̈des L.), costmary (Balsamita major Desf., syn. Chrysanthemum balsamita L.), Roman camomile (Anthemis nobilis L.), and tansy (Tanacetum vulgare L.) were tested in refined, bleached and deodorised rapeseed oil at 40°C. The concentrations of the extracts added were in the range from 0.02 to 0.20% (w/w). The rate of oxidation was assessed by the measurement of peroxide value (PV) and calculation of such characteristics as induction period (IP), when PV reaches 20 meq kg⁻¹, protection factor (PF), which is the ratio of IP of the sample with additive with IP of the sample without additive, and AA (the ratio of IP increase of the sample with extract with the IP increase of the sample with butylated hydroxytoluene). Sage and sweet grass extracts were found to be most effective in stabilising rapeseed oil, followed by tansy, Roman camomile, costmary and sea buckthorn in a decreasing order. The IP of rapeseed oil increased with extract concentration. AA's of the extracts added at different concentrations were the following: sage, sweet grass (0.05, 0.1 and 0.2%) and tansy (0.2%) — very high, (PF>3); tansy and Roman camomile (0.1%) — medium (PF=2–2.5), tansy (0.05%), Roman camomile (0.02 and 0.05%) and sea buckthorn (0.1 and 0.2%) — low (PF=1.5–2.0), tansy (0.02%) — very low (PF=1.0–1.5). The extracts of sea buckthorn (0.02 and 0.05%) slightly increased the formation of peroxides in rapeseed oil as compared with pure oil.     

Antioxidant Activities of the Supercritical and Conventional Satureja montana Extracts

ABSTRACT:  The antioxidant activities of the volatile and the nonvolatile fractions from  Satureja montana  obtained by supercritical fluid extraction (SFE) and by conventional techniques, hydrodistillation (HD) and soxhlet extraction (SE), were compared. A good agreement between DPPH and rancimat methods was obtained showing that the extracts were able to scavenge free radicals and to inhibit lipid oxidation. The volatile oil (obtained by SFE at 90 bar/40 °C) was the most effective extract, presenting the lowest EC₅₀ (0.06 g/L) and the highest protector factor (PF = 2.03). These results demonstrated the advantages of SFE over conventional techniques by avoiding thermodegradation and hydrolysis reactions. Furthermore, volatile oil is 15 times richer in thymoquinone than the essential oil (HD). This compound is of great importance due to its antioxidant, neuroprotective, and anti-cancer activities. The combination of carvacrol + thymol + thymoquinone in volatile oil may be responsible for the increase in the antioxidant activity when compared to HD, which demonstrates that, in this case, SFE improves value to the final product.     

EVALUATION OF GLOBAL YIELD, COMPOSITION, ANTIOXIDANT ACTIVITY AND COST OF MANUFACTURING OF EXTRACTS FROM LEMON VERBENA (ALOYSIA TRIPHYLLA[L'HÉRIT.] BRITTON) AND MANGO (MANGIFERA INDICA L.) LEAVES

In this work, the global yields, composition and antioxidant activity (AA) of extracts from lemon verbena (Aloysia triphylla) and mango (Mangifera indica) leaves obtained by different separation processes were determined. Lemon verbena extracts were obtained by supercritical fluid extraction (SFE), while mango leaf extracts were obtained by SFE, low‐pressure solvent extraction (LPSE) and hydrodistillation. The extract's constituents were analyzed by thin‐layer chromatography, gas chromatography/mass spectrometry and gas chromatography/flame ionization detector. The AA of the extracts was evaluated by the coupled reaction of β‐carotene/linolenic acid. The cost of manufacturing (COM) was estimated for the SFE extracts. Higher global yields were obtained using SFE at 350 bar/45C (1.49%) for lemon verbena and LPSE (3.04%) for mango. The AAs of the extracts were larger than that of the β‐carotene for both plants. The minimum values of COM were U.S.$26.96 and 52.45/kg of extract for lemon verbena and mango, respectively.     

Supercritical fluid extraction of oils from apple seeds: Process optimization,chemical characterization and comparison with a conventional solvent extraction

Oils from apple seeds were extracted with the application of supercritical fluid (SFE) and Soxhlet techniques. The effect of SFE experimental variables such as pressure (10–30 MPa), temperature (40–60 °C) and carbon dioxide flow rate (1–8 L/h) on the yield, antioxidant activity and total phenolic content was investigated using a central composite design. The experimental data were fitted with a second-order polynomial equation using regression analysis. The maximum yield, obtained at the optimum processing conditions (24 MPa, 40 °C, 1 L/h of carbon dioxide flow rate, 140 min) was 20.5 ± 1.5% (w/w). For comparison, the yield from Soxhlet extraction was 22.5 ± 2.5% (w/w). Both techniques produced an oil with a fatty acids profile rich in linoleic acid. However, the extract from SFE was higher in linoleic acid (63.76 ± 4.96 g/100 g_oil) than that achieved by Soxhlet (49.03 ± 3.85 g/100 g_oil). Despite the higher unsaturated fatty acids content, SFE extracts reported a higher oxidative stability (21.4 ± 1.2 h) compared to that one extracted by Soxhlet (12.1 ± 1.1 h). This result was expport addressing the extraction of apple seed oil by supercritical fluid at pressures lower tha The most abundant phenolic compound found in the extract was phloridzin (2.96 ± 0.046 μg/gs_eed in SFE oil and 1.56 ± 0.026 μg/g_seed in Soxhlet). Instead, amygdalin, one of the antinutrients present in seeds, was not detected in the SFE oil.Industrial relevanceThe present study provided results addressing the extraction of apple seed oil by supercritical fluid at pressures lower than 30 MPa. The process allowed extracting an oil that was rich in unsaturated fatty acids, oxidative stable thanks to the high antioxidant activity, and free from anti-nutritional compounds.     

Subcritical fluid extraction of Lycium ruthenicum seeds oil and its antioxidant activity

The effective, energy-saving and green subcritical fluid extraction (SFE) technology was applied to obtain the oil from Lycium ruthenicum seeds (LRSO). The optimal conditions of extraction parameters were found using response surface methodology with Box-Behnken experimental design. The maximum extraction yield of 21.20% was achieved at raw material particle size of 0.60 mm, extraction pressure of 0.63 MPa, temperature of 50 °C and time of 48 min. Other traditional extraction technologies were comparatively used. The physicochemical property of LRSO was analysed and the chemical compositions indicated that they were rich in unsaturated fatty acid, β-carotene, tocopherols and total phenolics. Furthermore, the antioxidant activity of LRSO was evaluated by scavenging activity of three kinds of radicals (DPPH·, ·OH and O₂^-·) and lipid peroxidation in vitro. And its results showed the oil had the potential to be a novel antioxidant agent for using in the field of food, pharmaceuticals and cosmetics.     

Supercritical CO2 extraction of oil from Arctic charr side streams from filleting processing

Although Arctic charr side streams contain limited amounts of fish flesh, they are a rich fish oil source (46.3 ± 0.6%). The aim of the study was to investigate the potential for valorization of Arctic charr filleting side streams through the extraction of oil by supercritical CO₂ technology. The effect of temperature (40 °C and 80 °C) and pressure (20, 35 and 45 MPa) on the final extract after supercritical fluid extraction (SFE) was evaluated. Temperature increase enhanced the yield but decreased the antioxidant activity at 45 MPa, did not affect the yield and the antioxidant activity at 35 MPa, whereas yield was limited at 20 MPa and 80 °C. Extracts were rich in monounsaturated fatty acids (56.7–58.3%, especially oleic acid 37.2–38.0%), and polyunsaturated fatty acids (20.2–26.1%, especially DHA 7.3–11.4%). The presence of astaxanthin significantly preserved the extracts from oxidation.Industrial relevanceSupercritical carbon dioxide extraction is a green technology appropriate for the recovery of non-polar and heat sensitive compounds. The extracted Arctic charr oils were rich in polyunsaturated fatty acids and astaxanthin which inhibited oxidation in combination with the absence of oxygen and light during the process. This technology could be an excellent alternative for more sustainable valorization of fish processing side streams.     

Comparison of essential oils of clove buds extracted with supercritical carbon dioxide and other three traditional extraction methods

Supercritical fluid extraction (SFE) of essential oil from clove buds with CO₂ was explored. The effect of different parameters, such as temperature (30 °C, 40 °C, 50 °C), pressure(10 MPa, 20 MPa, 30 MPa) and particle size (three degree index), on the extraction yield and the content of eugenol in extracts was investigated using three-level orthogonal array design. The experimental results show that the temperature has the largest effect on the eugenol content of the extracts, and particle size has the maximum effect on the oil yield. The essential oil of 19.56% yield, in which the maximum content of eugenol in extracts is 58.77%, can be extracted from clove buds at pressure of 10 MPa and temperature of 50 °C. Essential oil of clove buds obtained by SFE, hydrodistillation, steam distillation and Soxhlet extraction were further analyzed by gas chromatography/mass spectrometric detection to compare the extraction methods. Twenty three compounds in the clove oils have been identified, showing that the composition of the clove oil extracted by different methods is mostly similar, whereas relative concentration of the identified compounds is apparently different. General characteristics of the clove oils obtained by different methods were further compared, and SFE is considered as the optimum process among the four processes for obtaining clove oil with high quality.     

油菜籽中多酚的分布及加工过程对菜籽多酚含量的影响

对油菜籽壳粕和脱壳后的菜籽肉粕中提取液的总酚含量、对DPPH 自由基清除能力以及FRAP 抗氧化能力进行比较,并采用液质联用法对提取液中的主要成分进行鉴定,对其中的芥子酸和芥子碱进行定量分析。结果表明：菜籽肉粕提取液中的总酚含量、对DPPH 自由基清除能力以及FRAP 抗氧化能力约为菜籽壳粕中的两倍,芥子酸和芥子碱的含量分别为菜籽壳粕中的约2.5 倍和1.5 倍。通过对实验室溶剂除油的菜籽粕与工业高温粕比较发现,高温榨油过程会使菜籽的总酚含量、抗氧化性、芥子酸和芥子碱含量有所下降,其中总酚含量下降了12.06%,DPPH 自由基和FRAP 抗氧化值分别降低10.0% 和5.6%,芥子酸和芥子碱含量分别下降了5.6% 和21.12%。     

Essential oil composition and antimicrobial activity of Origanum majorana L. extracts obtained with ethyl alcohol and supercritical carbon dioxide

Volatile components of marjoram (Origanum majorana L.) essential oil obtained by hydrodistillation and extracts obtained by solvent extraction with ethyl alcohol and supercritical fluid extraction (SFE) were investigated. The compositions of volatile compounds in essential oil, ethanolic and SFE extracts were determined by GC and GC–MS. The antimicrobial properties of marjoram solvent extracts were investigated with microbiological tests against food borne fungi and bacteria strains. Extracts obtained by SFE at high pressure and temperature showed significantly stronger antimicrobial properties in comparison to the slight inhibitory effects of the ethanolic extract. The results support the notion that extracts obtained by SFE might have a role as flavourings and natural colourants as well as use as preservatives in food and cosmetic systems.     

Antioxidant activity of sweetgrass (Hierochloë odorata Wahlnb.) extract in lard and rapeseed oil emulsions

The antioxidant activities of sweetgrass (Hierochlo? odorata) and sage (Salvia officinalis) extracts were studied in emulsions of lard and rapeseed oil using soy lecithin as an emulsifier, and addition of cupric acetate as an oxidation catalyst. The antioxidant activity was about the same in the two substrates. The stability against autoxidation was substantially increased by both sweetgrass and sage extracts and their combination. The stability was particularly high, if citric acid and/or ascorbyl palmitate were added to plant extracts.     

Central composite design for the optimization of supercritical carbon dioxide fluid extraction of fatty acids from Borago officinalis L. flower

Abstract: In the present study, fatty acids and essential oils of the flower of borage (Borago officinalis L.) were obtained by supercritical carbon dioxide fluid extraction under different conditions. The extracts obtained were compared to oils of borage flower oil isolated by hydrodistillation. The obtained oils were analyzed by gas chromatography mass spectrometry. The compounds were identified according to their retention indices and mass spectra. The experimental parameters of supercritical fluid extraction (SFE) were optimized using a central composite design after a full factorial experimental design. Extraction yields based on SFE varied in the range of 0.02% to 1.96% (w/w), and the oil yield based on the hydrodistillation was 0.05% (v/w). The optimum conditions of SFE were obtained at a pressure of 350 atm, a temperature of 65 °C, a methanol modifier volume of 100 μL, and static and dynamic extraction time of 10 min. Main components of the extracts under optimum SFE conditions were palmitic acid, linoleic acid, γ‐linolenic acid, and oleic acid. The results indicated that by using the suitable extraction conditions, SFE is more effective than the conventional hydrodistillation method in the extraction of fatty acids and the preservation of its quality. Practical Application: SFE is a good technique for the extraction of oils from plants. The extraction yields by SFE are more than the conventional method. SFE is used on a large scale for production of essential oils and pharmaceutical products from plants.     

Supercritical carbon dioxide extraction of antioxidant fractions from selected Lamiaceae herbs and their antioxidant capacity

Antioxidant fractions from four herb spices belonging to the Lamiaceae family: rosemary (Rosmarinus officinalis), sage (Salvia officinalis), thyme (Thymus vulgaris) and hyssop (Hyssop officinalis) were isolated using supercritical CO₂ at 35 MPa and 100 °C. The antioxidant fractions were characterized chemically by HPLC-DAD/ESI-ToF-MS. Antioxidant activity of obtained extracts was determined by measuring their ability to scavenge stable 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and reactive hydroxyl radical during the Fenton reaction trapped by 5,5-dimethyl-1-pyroline-N-oxide (DMPO), using electron spin resonance (ESR) spectroscopy. The antioxidant activity of the extracts was compared to the activity of butylated hydroxyanisole (BHA) and Flavor' Plus? water-soluble rosemary extract. In DPPH radical assay the order from the strongest to the weakest antioxidant activity was: BHA, thyme extract, Flavor' Plus?, rosemary and sage extracts, and hyssop extract, while in hydroxyl radical assay order was: Flavor' Plus?, sage extract, rosemary extract, hyssop extract, BHA and thyme extract.Industrial relevanceSpices and herbs have been used not only for flavoring food but also for improving the overall quality of the product and to extend the shelf-life of foods. The present investigation relates to the field of food additives, and particularly to an antioxidant fractions from four herb spices which belong to the Lamiaceae family: rosemary (Rosmarinus officinalis), sage (Salvia officinalis), thyme (Thymus vulgaris) and hyssop (Hyssop officinalis). Butylated hydroxyanisole (BHA) and Flavor' Plus? are used in food industry as antioxidants due to their ability to prolong the shelf-life of foodstuffs by protecting them against deterioration caused by oxidation, such as fat rancidity, colour changes, degradation of the flavor and loss of nutrient value. Synthetic antioxidants such as BHA now being replaced by natural antioxidants because of their possible toxicity and due to a suspected action as promoters of carcinogens. The present study confirms that investigated herb spices belonging to the Lamiaceae family present important sources for the production of food additives.     

Phenolic compounds from winemaking waste and its antioxidant activity towards oxidation of rapeseed oil

The effects of extraction parameters on bioactive compound contents of winemaking waste extracts (WWE) and its effect on rapeseed oil oxidative stability were evaluated. Research showed that the total phenols and anthocyanin contents and antioxidant activity (AA) of WWE significantly depended on the extraction parameters. Increasing the temperature (60 °C) and time (5 h) of extraction and an addition of water to ethanol statistically improved the rate of active component extraction. HPLC analysis showed that procyanidin B_2, catechin, gallic acid, γ‐resorcylic acid and p‐coumaric acid were the major phenolic compounds of WWE. Important correlations between total phenolic compounds quantified by HPLC and both DPPH and (ferric reducing antioxidant power) (FRAP) values were found. WWE added to the oil at three different levels clearly slowed down the process of fatty acid oxidation, inhibiting hydroperoxide formation by about 86%, comparable with BHT, while it was more effective than that of α‐tocopherol. When using volatile compound formation as a marker of lipid oxidation, WWE at the level of 2000 ppm were the most effective inhibitors of the decomposition of hydroperoxides. The research showed that the WWE are a rich source of phenolic compounds with powerful antioxidant activities and are suitable for preventing rapeseed oil oxidation.     

Optimization of subcritical fluid extraction of seed oil from Nitraria tangutorum using response surface methodology

Subcritical fluid extraction (SFE) technology was used to extract oil from Nitraria tangutorum seed. The best possible combination of extraction parameters was found using response surface methodology (RSM) in a three-variable, three-level Box-Behnken experimental design (BBD). The optimum extraction parameters were an extraction time of 40 min, an extraction pressure of 0.60 MPa, an extraction temperature of 44 °C and a raw material particle size of 0.45 mm. Conventional solvent extraction and supercritical CO₂ fluid extraction were comparatively used. The yield of seed oil obtained using SFE was 12.92%, which was similar to or higher than the other methods. The chemical compositions of the seed oil, determined by GC–MS, indicate that its unsaturated fatty acids content was 97%. SFE proved to be an effective technique for extracting oil from N. tangutorum.     

Effects of blackcurrant seeds and rosemary extracts on oxidative stability of bulk and emulsified lipid substrates

The effects of blackcurrant seeds extract and commercially available rosemary extracts on rapeseed oil and rapeseed oil triacylglycerol oxidative stability were evaluated. The antioxidant activity of plant extracts was investigated, both in bulk and emulsified lipid substrates, and compared with those of α-tocopherol and BHT. The investigation showed that blackcurrant seeds and rosemary extracts are the source of active antioxidants and are appropriate for food lipid stabilization. The extracts performed better in stripped substrates as they may interfere with native tocopherols present in rapeseed oil and show different activity according to the presence of water. α-Tocopherol, a 200 ppm, was inactive in bulk and emulsified rapeseed oil but was an effective antioxidant in triacylglycerols. BHT showed the best performance of all used additives in emulsified substrates.