Increasing Extraction Temperature Research Articles

Cryogenic vacuum distillation vs Cavitron methods in ecohydrology: Extraction protocol effects on plant water isotopic values

Stable isotope ratios of hydrogen and oxygen in plant water are widely used for water tracing in ecohydrology studies. In this approach, plant water is extracted for isotopic analysis of δ2H and δ18O. Among the extraction methods, cryogenic vacuum distillation (CVD) has been the most popular, but its impact on the isotopic composition of plant water is currently under debate. Newer Cavitron method have been proposed to replace CVD method for xylem water extraction. These recommendations have been largely based on comparisons between Cavitron-xylem water with low temperatures CVD-xylem water. However, the CVD protocol (extraction temperature and time) varies widely across laboratories, and no direct, systematic comparison has yet been made between extraction temperature and time protocols vs. the Cavitron approach. Here we compared the isotopic values of xylem water from the same tree obtained through CVD extraction at 60 °C (60, 120, 240, 360 min), 100 °C (30, 60, 120, 240 min), 140 °C (15, 30, 60, 120, 240 min), and 200 °C (15, 30 min). Subsequently, we compared the results of CVD-xylem water with Cavitron-xylem water. Our data show that isotopic values for CVD-xylem water became more positive with increasing extraction time under the same extraction temperature. Such extractions also became more isotopically positive with increasing extraction temperature for the same extraction time. When total extraction efficiency exceeded 98 %, there was no δ18O difference in CVD-xylem water among any of the different protocols (p > 0.05). However, lower extraction temperatures resulted in more negative δ2H when compared to higher temperature extraction (p < 0.05). Cavitron-xylem water was close to CVD-xylem water (average difference of 3 ‰ for δ2H and 0.5 ‰ for δ18O, n = 79) when total extraction efficiency for CVD was below 98 %. But for extraction efficiencies beyond 98 %, the Cavitron-xylem water was more negative in δ2H (17.3 ‰, n = 70) and δ18O (1.7 ‰, n = 70) than CVD-xylem water. Compared to Cavitron-xylem water, CVD-xylem water at 200 °C with extraction efficiency > 98 % was closer to the soil water. Further study is necessary to conduct a complete cross-comparison between Cavitron and CVD at different temperatures with different species at various water and salt stress conditions. But our results suggest that abandoning CVD for plant water maybe premature until such complete comparison work is done.

Production of trans-fat-free margarine prepared using catfish oil and palm stearin with the addition of avocado waste oil for tocopherol enrichment

Catfish oil (CFO) is rich in unsaturated fatty acids (UFA) which are potentially produced into margarine through the blending method with palm stearin (PS) addition. The high UFA content of CFO causes margarine to be susceptible to oxidative damage, which can also trigger the formation of trans fatty acids (TFA). An antioxidant compound in the form of avocado waste oil (AWO) that contains tocopherol is added during margarine production to inhibit oxidative damage and TFA formation in the final product. Thus, the temperature and duration of CFO extraction, avocado peel and seed ratio of AWO extraction, and CFO:PS:AWO ratio of margarine production were analyzed for their effect on CFO, AWO, and margarine characteristics. This study was conducted by several stages; CFO extraction with temperature (50, 70 and 90oC) and duration (1 and 2 hrs) treatment, AWO extraction with avocado peel and seed ratio treatment (100:0, 75:25, 50:50, 25:75, 0:100), and margarine production with CFO:PS:AWO ratio treatment (41:40:0, 36:40:5, 31:40:10, 26:40:15, 21:40:20). The results showed that the increasing extraction temperature and duration caused the decrease of CFO hydrolytic-oxidative stability. The best CFO extraction treatment was 50oC and 1 hr of extraction. The increasing avocado peel ratio in AWO extraction led to the increase of AWO antioxidant potential. The best AWO extraction treatment was the ratio of peel:seed = 75:25. The addition of AWO in margarine production for tocopherol enrichment was proven to suppress oxidative damage and TFA formation. The best margarine production treatment was the 3rd formulation (10% of AWO) with UFA-rich and trans-fat-free margarine characteristics. It was selected as the most preferred color, taste and flavor of margarine. These studies’ results are beneficial for the product development of UFA-rich and transfat-free margarine with good oxidative stability prepared using freshwater fish oil and plant byproduct oil.

Influence of Extraction Temperature on the Quality of Neem Seed Oil: Preliminary Investigation

The storage of neem oil for a long time before usage comes along with challenge of quality retain ability of the oil; and the extraction methods can affect the quality of neem seed oil. This research work compared the mechanical expression method to the solvent extraction method to find a better method that will give high-grade neem oil for long-term storage. A plant with a capacity of 50 kg/day of neem seed kernel was used to extract oil from neem seed using ethanol as extraction solvent. The increase of extraction temperature from 20 oC (mechanically expressed) to 78 oC leads to decrease of iodine value from 62.70 to 60.10 gI2/100 g; increase of acid value from 3.4 to 4.2 mg KOH/g and increase of saponification value from 158.74 to 210.18 mgKOH/g. The Fames standard method was used for the GC – MS analysis and the percentage composition of the polyunsaturated components in the 20 oC (mechanically expressed), 50 oC, 55 oC, 60 oC and 78 oC oils were 21.58, 6.33, 3.09, 1.83 and 0.21% respectively. The changed of extraction temperature from 20 oC to 78 oC brings about reduction of polyunsaturated components from 21.58% to 0.21%. The increase of extraction temperature leads to conversion of unsaturated components to saturated components due to auto – oxidation process. This is clearly seen as the extraction temperature increased from 20 oC to 78 oC, the percentage composition of the saturated components increased from 22.40% to 43.70% and the polyunsaturated component decreased from 20.47% to 0%. The fatty acid composition associated with the 78 oC oil are: Oleic acid, 46.61%; Stearic acid, 11.83%; Palmitic acid, 16.54%; 11 – Octadecenoic acid, 3.58%; Cis – Vaccenic acid, 5.90%; Cyclopropaneoctanal, 11.19%; Squalene, 0.21% and Trimethylsilyl – di(timethylsiloxy) – silane, 4.14%. The functional groups identified in the 78 oC oil were C – H, C = O, C – C and C – O. Based on the lowest iodine value, lowest percentage composition of the polyunsaturated component value and high percentage composition of saturated component, the neem oil obtained at 78 oC from the miscella is considered as the high grade neem oil because it is less reactive due to lowest percentage composition of polyunsaturated and can be stored for long time before usage. Furthermore, the results from this work will assist manufacturers in selecting the extraction temperature for particular application of the neem seed oil. The extracted oil is recommended for soap production due to its high saponification value.

Selective extraction of aromatics from residual oil with subcritical water

Based on theoretical calculations and experimental characterizations, the extraction of heavy oil components using subcritical water (Sub-CW) as an extraction solvent was studied in the temperature range of 250–325 °C. According to theoretical calculations, small-scale polycyclic aromatic hydrocarbons (PAHs) are preferentially dissolved in Sub-CW. Meanwhile, the dissolution of heavy oil molecules with large-scale aromatic structures and heterocyclic rings in Sub-CW is hindered. The increase in temperature reduces the hydrogen bonding force between water molecules and the van der Waals repulsion between Sub-CW and PAHs, promoting the dissolution of PAHs in Sub-CW. Extraction experiments applied in a semi-continuous device confirm that Sub-CW selectively extracts aromatic hydrocarbons from heavy oil. Increasing extraction temperature increases the yield of the extract. The aromatic hydrocarbon content in the extract at 325 °C reaches 80 wt%, which is 27 wt% higher than feedstock value. In addition, the asphaltene content in the extract is reduced from the feedstock value of 14 wt% to 2 wt%.

Antioxidant and Antimicrobial Activity of Essential oil Extracted from Trachyspermum Ammi (ajwain) Seeds: an In-vitro Study

The food industry uses essential oils derived from natural sources as flavouring and preservatives. The purpose of this study is to investigate how temperature affects the essential oil extracted from Trachyspermum ammi, seeds which has the best antioxidant and antimicrobial properties, in order to find a green substitute for toxic chemically produced preservatives used in food and pharmaceutical chemistry. Trachyspermum ammi (ajwain seeds) seeds were hydrodistilled at various temperatures (60°C to 90°C). The amount of essential oil was found to decrease on increasing temperature (2.1ml, 1.5 ml and 1.0 ml at 70°C, 80°C, and 90°C respectively). Hence, 70°C was the ideal temperature for extracting the essential oil from ajwain seeds. 25 components were discovered in the essential oil extracted from ajwain seeds by GC-MS technique. The predominant ingredient was shown to be thymol (31.40%). The percentages of scavenger activity against hydrogen peroxide were 70.75%, 86.99%, and 95.28% for 70°C, 80°C, and 90°C respectively. Due to the presence of the largest concentration of thymol (67.66%), the results showed that essential oil extracted at 90°C demonstrated the highest level of antioxidant property. By using the disc diffusion method, the antimicrobial activity of an essential oil made from ajwain seeds was evaluated. MIC50 of standard essential oil of Trachyspermum ammi seeds against gram positive strain was observed 10 µL/mL of culture and 25µL/mL of culture was observed against gram negative bacteria. Essential oil extracted at 70°C showed antimicrobial activity by forming zones of inhibition with diameters including discs of 18.3 mm and 14.36 mm against S. aureus and E. coli, respectively. Essential oil extracted at 80°C produced zones of inhibition with diameters of 18.68 mm and 15.30 mm, respectively. In the case of essential oil extracted at 90°C, the zones of inhibition against S. aureus and E. coli had diameters of 18.690.3 mm and 15.38 mm, respectively. As a result, using Trachyspermum ammi essential oil as a food preservative and the temperature at which it is extracted are unaffected by an increase in extraction temperature. Hence, essential oil obtained from Trachyspermum ammi seeds can be used as green alternative of chemically synthesized toxic preservatives used in food and pharmaceutical chemistry.

Enhanced extraction of bioactive compounds from propolis (Apis mellifera L.) using subcritical water

The bioactive compounds and antioxidant activities of propolis extracts were investigated using subcritical water extraction (SWE). SWE was performed by varying temperature (110–200 °C) and time (10–30 min). SWE using only water as solvent successfully to extracted bioactive compounds from propolis using high-purity glass thimbles. The concentrations of galangin (16.37 ± 0.61 mg/g), and chrysin (7.66 ± 0.64 mg/g) were maximal at 200 °C for 20 min, and 170 °C for 20 min, respectively. The antioxidative properties from propolis increased with the increasing extraction temperature and extraction time on SWE. The maximum yields of the total phenolics (226.37 ± 4.37 mg/g), flavonoids (70.28 ± 1.33 mg/g), and antioxidant activities (88.73 ± 0.58%, 98.86 ± 0.69%, and 858.89 ± 11.48 mg/g) were obtained at 200 °C for 20 min. Compared with using ethanol extraction (at 25 °C for 24 h, total phenolics = 176.28 ± 0.35, flavonoids = 56.41 ± 0.65, antioxidant activities = 72.74 ± 0.41%, 95.18 ± 0.11%, 619.51 ± 8.17 mg/g), all yields of SWE extracts obtained at 200 °C for 20 min were higher. SWE is suitable for a much faster and more efficient method extracting bioactive compounds from propolis compared to traditional extraction method.

Comparisons of pulsed ultrasound-assisted and hot-acid extraction methods for pectin extraction under dual acid mixtures from onion (Allium cepa L.) waste.

The aim of this study is to compare the physicochemical properties and yields of pectins extracted from onion waste under hot acid (HAE) and pulsed ultrasound-assisted extraction (PUAE) methods using different organic-inorganic acids, their mixtures, and pure water. The extraction temperature for experiments carried out under HAE was kept at 90°C for 90 min, whereas PUAE experiments were accomplished at RT in 15 min. In general, HAE gave better pectin yields compared with PUAE due to the significance of the increasing extraction temperature for the release of pectin from the plant matrix. While the maximum pectin yield from onion waste was 16.22% for HAE, the highest yield for PUAE was 9.83%. PUAE provides less time- and energy-consuming extraction of pectin within 15 min and thus seems to be more economic compared with the HAE. According to the physicochemical properties (equivalent weight (EW), degree of esterification (DE), methoxyl (MeO), and galacturonic acid (Gal-A) contents) of obtained pectins, extracted pectins were mostly high methoxy pectin. While the DE and MeO values of pectins extracted in organic acid conditions under HAE were higher, these values were found to be higher for pectins extracted in inorganic acids under PUAE. For acid mixtures, the DE and MeO values of pectins under HAE were mostly found to be lower than those under PUAE. Sequential PUAE and HAE methods for the extraction of pectin from onion waste were also found to be useful in terms of obtaining higher yields and better physicochemical properties. The highest pectin yield was 20.32% for the sequential PUAE and HAE methods. FT-IR analyses of the extracted pectins by both HAE and PUAE methods showed similar vibration bands compared with those of commercial citrus pectin.

Appropriateness of Anogessus leiocarpus leaves and bark as vegetable tannins traditionally used in leather making in Sudan

Chrome tanning industry is dominated globally owing to its high versatility in quality leather production. However, Environmental impacts of chromium have shifted the interest of present study to chrome-free options. Vegetable tannins have been proven to be environmentally safe producing good quality leather with comparable properties as that of chrome tanned leather. As such, scarcity of vegetable tannin supply demands characterization of non-commercialized sources locally available to feed local tanners. A simple extraction technique was used with different temperature 35, 50, &amp; 85 oC. Leaves and barks from Anogessus leiocarpus grown in Sudan can produce commercially acceptable tannins in terms of extract yield, tannin, total phenolic, flavonoid contents, and crosslinking ability comparable to the extract from A. mearnsii barks, which is a worldwide known to be commercial tannin source. Results shows that temperature influences on extraction yields and tannin content was low, except for extract from Anogessus leiocarpus leaves that has shown an increase pattern with raise in temperature. Total phenolic and flavonoid content varied insignificantly with increase in extraction temperature, except for total flavonoid content of extract from Anogessus leiocarpus leaves that observed to be high at 50 oC (30.7). Variations in extract properties between extracts from plant parts studied in this work were significant. Tensile strength values of tanned skin with leaves extracts are higher than that tanned with barks. On the other hand, tanned skin with leaves extract produced greater skin elongation 40.6±0.35 compared to barks extract.

Citric Acid Method Optimization for Pectin Extraction from Unripe ‘Saba’ Banana (&lt;i&gt;Musa acuminata X Musa balbisiana&lt;/i&gt; BBB) Peels

The utilization of ‘Saba’ banana peels from processing wastes has shown potential as sources of pectin, which is widely used in the food and pharmaceutical industries. An optimized citric acid extraction of pectin from mature unripe 'Saba' banana peel wastes was developed using a three-factor Box-Behnken design considering the effects of extraction temperature (75-90°C), extraction time (1-5 hours), and agitated precipitation time (30-180 minutes) on the crude pectin yield. Results showed that the generated model is significant and that the extraction temperature and time significantly affected pectin yield and its equivalent weight. An increase in extraction temperature (up to 90°C) accompanied by prolonged extraction time can increase extraction yield. Optimum extraction conditions of 85°C for 5 h, with precipitation for 30 min resulted in the highest crude pectin yield (32.89% dry basis) in the experiment. The extracted pectin showed higher ash content (3.63%) and lower equivalent weight (513.05), methoxyl content (4.88%), moisture content (10.15%), and anhydrouronic acid (44.43%), than that of commercially available citrus pectin while degree of esterification did not vary.

Extraction of monoterpenes from coriander (Coriandrum sativum L.) seeds using subcritical water extraction (SWE) technique

Subcritical water extraction (SWE) of monoterpenes from coriander seeds and effect of extraction conditions were investigated varying temperature (170–200 °C) and time (5–20 min). Monoterpenes was influenced by differences in their chemical structures and SWE conditions. The extraction efficiency of linalool was decreased with the increasing extraction temperature and extraction time, whereas linalool oxide was increased due to conversion of linalool to linalool oxide by hydrothermal oxidation. Geraniol, which has the same chemical formula as linalool, was extracted at a high temperature (170 °C) owing to the different placement of hydroxyl groups. The efficiency of SWE for geraniol (1.22 ± 0.22 mg/g) and linalool oxide (0.30 ± 0.09 mg/g) was higher than that of conventional extraction methods (hexane, methanol, hot water, and hydrodistillation). Therefore, SWE can be used to effectively and selectively extract monoterpenes by exploiting temperature changes in short extraction time.

Hyper-coal as Binder for Coking:—Macroscopic Caking Property, Microstructure Basis and Extraction Temperature Optimization Index

ABSTRACT It is an effective way to utilize low-rank coal to obtain Hyper-coal by thermal extraction. Taking Shanxi lignite as raw material, the Hyper-coal was obtained by extraction at several temperatures. The basis of Hyper-coal as an excellent upgrading binder for coking was comprehensively studied from two aspects of macrocohesion index and microstructure. The experimental results show that the content of ash and sulfur in the Hyper-coal is low, and the content of light components is increasing with the increase of extraction temperature. The thermoplasticity of hyper-coal is generally high, the fluidity of colloid formed by pyrolysis is higher than that of conventional coking coal, and the bonding ability also reaches the level of fat coal. The source of high thermoplasticity of hyper-coal mainly depends on its microstructure, such as high aliphatic hydrocarbon content and wide thin compact carbon network structure. The optimum extraction temperature was 380°C. Generally speaking, Hyper-coal can be used as an excellent binder for coking.

Effect of Extraction Temperature on Pressurized Liquid Extraction of Bioactive Compounds from Fucus vesiculosus.

This study was aimed at investigating the effect of low polarity water (LPW) on the extraction of bioactive compounds from Fucus vesiculosus and to examine the influence of temperature on the extraction yield, total phenolic content, crude alginate, fucoidan content, and antioxidant activity. The extractions were performed at the temperature range of 120–200 °C with 10 °C increments, and the extraction yield increased linearly with the increasing extraction temperature, with the highest yields at 170–200 °C and with the maximum extraction yield (25.99 ± 2.22%) at 190 °C. The total phenolic content also increased with increasing temperature. The extracts showed a high antioxidant activity, measured with DPPH (2,2-Diphenyl-1-picrylhydrazyl) radicals scavenging and metal-chelating activities of 0.14 mg/mL and 1.39 mg/mL, respectively. The highest yield of alginate and crude fucoidan were found at 140 °C and 160 °C, respectively. The alginate and crude fucoidan contents of the extract were 2.13% and 22.3%, respectively. This study showed that the extraction of bioactive compounds from seaweed could be selectively maximized by controlling the polarity of an environmentally friendly solvent.

작약 뿌리의 유용성분 추출을 위한 초음파 추출조건 최적화

Peony root is a medicinal plant containing potent bioactive compounds. This study used response surface methodology (RSM) to optimize ultrasonic-assisted extraction (UAE) conditions of antioxidant compounds from peony roots. A central composite design consisting of extraction temperature (30-70°C), ethanol concentration (20-100% v/v), and extraction time (15-55 min) was used to determine the significance of each extraction condition on the total polyphenol, paeoniflorin, and myricetin contents and 2,2¢-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)- scavenging activity of the extracts. The ABTS-scavenging activity and myricetin content increased with an increasing extraction temperature. Further, at low ethanol concentrations, paeoniflorin and myricetin contents increased. Superimposition of 4D graphs revealed that an extraction temperature of 60-65°C, ethanol concentration of 40-50%, and extraction time of 40-50 min were optimal extraction conditions for peony root. A validation experiment was conducted using 45% ethanol at 63°C for 45 min. Under these UAE conditions, the experimental values of total polyphenol, paeoniflorin, and myricetin contents, and ABTS-scavenging activity were 101.80 mg GAE/g, 46.87 mg/g, 184.30 mg/g, and 23.13%, respectively. The validation experiment revealed slight differences between the experimental and predicted values (less than 10%), confirming the optimal UAE conditions for obtaining peony root antioxidant compounds via RSM. This study provides valuable information in developing functional food, medicine, and cosmetic using peony root extracts.

Advantages of MW-assisted water extraction, combined with steam explosion, of black alder bark in terms of isolating valuable compounds and energy efficiency

“Green” extraction of black alder bark using deionized water as an alternative to organic solvents and microwave (MW) - induced heating instead of convective/conductive heating was studied. An extractor of original construction with the MW capacity of 2.4 kW, equipped with a pressurized extraction chamber (V = 1350 cm3) and a condenser section, was used. The MW-assisted heating of the suspension up to the desirable temperature was performed with a uniform high rate of ~ 30 ℃ min−1. The yield of the black alder bark water extracts obtained by MW-assisted extraction varied from 15.4% to 26.4% (on bark dry matter) increasing with increasing extraction temperature (70–150 ℃) and increasing duration of the isothermal step of extraction (0–30 min). The electricity consumption per dry weight of obtained products needed for MW-assisted heating of the substrate containing suspension varied from 6.2 to 32.0 kWh kg−1 being higher at higher extraction temperature and longer duration of isothermal heating step. UHPLC-ESI-MS/MS, GC-FID, Py-GS/MS/FID, UV spectroscopy methods revealed that the main constituents of the obtained black alder bark water extracts were diarylheptanoids, condensed tannins, carbohydrates, organic acids, flavonoids, lignin related phenols. The MW-induced depolymerization of alder bark cell wall constituents (hemicellulose, lignin) evidenced by Py-GC/MS/FID, GC-FID, wet chemistry analyses of extracts and bark residues after extraction, resulted in the disruption of the bark cell wall and isolation of metabolites bound within it by microwaves-assisted extraction (MAE). Therefore, the black alder bark water extracts, obtained by MAE at 70–110 ℃, compared to those isolated by advanced accelerated solvent extraction (ASE) at a given temperature, have higher diversity and higher contents of different groups of phenolic extractives, including a higher content of their major class in alders – diarylheptanoids. The increase of the extraction temperature above 110 ℃ and the duration of extraction up to 30 min led to an increase of the content of carbohydrates and noticeable decrease of phenolics content in extracts, including the dominating diarylheptanoid - oregonin. The content of oregonin, having a high antioxidant activity and valuable biological activities, was in focus of our research and practical interest. MAE with dynamic heating to 90 ℃ without keeping of isothermal heating is the most attractive for obtaining of oregonin-enriched extracts, containing up to 57% of oregonin, in contrast to ASE water extracts with the maximum oregonin content of 39%. In this regime, two-fold less energy consumption (7 vs 15 kWh kg−1) and two and a half times more productivity (1.5 vs 0.6)% min−1 was achieved in comparison to the case of the ASE method used as reference.

A comparative study of supercritical fluid extraction and accelerated solvent extraction of lipophilic compounds from lignocellulosic biomass

The Box-Behnken experimental design technique investigated a comparative study of supercritical fluid extraction (SFE) and accelerated solvent extraction (ASE) of lipophilic compounds from pinewood sawdust. A response surface methodology was used to examine the effect of independent parameters and optimize the extraction yield of lipophilic compounds. The results showed that the increase in extraction temperature used for ASE positively influenced the yield of lipophilic compounds, whereas an increase in the flow rate of the cosolvent at temperature 50 °C, and pressure of 300 bar increased the yield achieved by SFE. The experimental data's quadratic polynomial models gave a coefficient of determination (R2) of 0.87 and 0.80 for ASE and SFE, respectively. The optimum conditions of ASE were temperature (160 °C), static time (12.5 mins), and static cycle (1), which resulted in a maximum yield of 4.2%. The optimum SFE conditions were temperature (50 °C), pressure (300 bar), carbon dioxide (CO2) flow rate (3.2 ml/min), and a 2 ml/min cosolvent flow rate that yielded 2.5% lipophilic compounds. ASE yielded higher extraction efficiency than SFE. Fourier transform infra-red (FTIR) spectroscopy and thermal analyses TGA/DSC evaluated the ultimate analyses of the lipophilic extracts. The FTIR results confirmed the presence of aliphatic groups, hydroxyl groups, and carboxyl groups. The thermal analysis showed that the degradation temperature of the lipophilic compounds occurred between 250 and 450 °C. Thereafter, Pyrolysis-Gas Chromatography Mass Spectrometry (Py-GC/MS) was used to identify the lipophilic compounds, which showed that the extracts were rich in fatty acids and terpenes.

Kinetics characteristics and thermodynamics analysis of soybean pods sterols extraction process

In order to make full use of biomass resources and extract sterols from the waste soybean pods, the mass transfer characteristic of the extraction process with ethanol aqueous solution was explored. The relationships between sterols mass concentration in extracting solution and extraction temperature and extraction time were studied under appropriate ethanol concentration and liquid-solid ratio. The kinetics model fitting, the mass transfer characteristic parameters research and thermodynamic analysis of extraction process were carried out. The result showed that the extraction process could be described by a second order kinetic model. Within the research scope, with the increase of extraction temperature, the mass transfer rate constant increased from 0.286 9 mL min−1 mg−1 to 0.848 5 mL min−1 mg−1, the half life was reduced from 20.9 min to 6.5 min, the activation energy of extraction process was 27.73 kJ mol−1. The Gibbs free energies were all less than zero, indicating that the sterols extraction process was spontaneous. The enthalpy change was 33.18 kJ mol−1 and entropy change was 122.2 J mol−1K−1 in the extraction process, the extraction process was an endothermic and entropy increases process. The research results could provide reference for the large-scale extraction of sterols from soybean pods.

Understanding the effect of time, temperature and salts on carrageenan extraction from Chondrus crispus

Alkali-free carrageenan extraction was performed on dried (around 1 cm size chips) gametophytic and tetrasporophytic Chondrus crispus at varying time and temperatures. For the gametophyte seaweed (containing κι-hybrid carrageenan and its precursors) the first 24 h extraction at room temperature resulted in an almost unrecoverable amount of carrageenan-rich precipitate (CRP) (1.6 ± 0.6 wt% of dry seaweed mass). A higher CRP yield was obtained (6.1 ± 0.6 wt% of dry seaweed mass) when a subsequent 24 h extraction was performed. Washing the gametophyte seaweed for 30 min with demineralized water prior to the first 24 h extraction reduced the conductivity of the seaweed dispersion and surprisingly improved its CRP yield (5.8 ± 0.1 wt% of dry seaweed mass). For tetrasporophytic C. crispus (λ-carrageenan) the first 24 h extraction at room temperature already resulted in a considerable CRP yield (18.6 ± 1.7 wt% of dry seaweed mass) despite the high conductivity of its seaweed dispersion. The CRP yield of gametophytic C. crispus improved with increasing extraction temperature. In the mentioned range of temperature, the maximum yield was obtained after extraction at 90 °C for 8 h (39.2 ± 0.0 wt% of dry seaweed mass). Finally, we observed at 60 °C that addition of different salts to the extraction dispersion prevented carrageenan from being extracted, with calcium salt showing the highest inhibitory effect.

Optimization of Ultrasound-Assisted Extraction of Anti-Glycation Agents from Ecklonia cava

ABSTRACT Ultrasound-assisted extraction conditions were optimized to improve the extraction of advanced glycation end products (AGEs) inhibitors from Ecklonia cava extracts using response surface methodology. Conditions considered were extraction temperature (30–70°C), ethanol concentration (20–100%), and extraction time (10–50 min). Dependent variables were dieckol content, yield, and degree of AGEs inhibition measured in three anti-glycation assay models; namely, bovine serum albumin (BSA)-fructose (Fru), BSA-methylglyoxal (MGO), and BSA-glyoxal (GO). Overall, dieckol content increased, but AGEs formation and yield decreased, with increasing ethanol concentration. In the BSA-MGO model, AGEs inhibition decreased with increasing extraction temperature. The four-dimensional graphs were superimposed to select optimum conditions. The optimum conditions were determined as 50–60°C of extraction temperature, 70%–85% of ethanol concentration, and 25–35 min of extraction time. The suitability of the prediction model was evaluated by comparing the actual and predicted values of responses, and the results confirmed that our prediction model is suitable. IC50 of Ecklonia cava extract against BSA-Fru, BSA-MGO, and BSA-GO was 0.44, 0.56, and 0.73 mg/mL, respectively. The AGEs inhibition effect of Ecklonia cava extract in the BSA-MGO model was better than that of aminoguanidine at the same concentration.

Optimization microwave‐assisted extraction of anthocyanins from cranberry using response surface methodology coupled with genetic algorithm and kinetics model analysis

AbstractCranberry contains abundant anthocyanins. In this study, the extraction process for the microwave‐assisted extraction (MAE) of anthocyanins from cranberry was optimized using response surface methodology coupled with genetic algorithm. The optimum extraction parameters to achieve the highest yield of anthocyanins (3.06 ± 0.05) mg/g from cranberry via MAE was obtained at extraction temperature of 50°C, extraction time of 8 s, ethanol concentration of 52% and solid‐to‐liquid ratio of 1:28 g/ml. The kinetic model of anthocyanins extraction from cranberry was established by plate model based on Fick's first Law, and the key model parameters (extraction rate constant and activation energy) were solved through the experimental results fitting. Results showed that the extraction rate constant increased significantly with the increase of extraction temperature. The activation energy of MAE anthocyanins from cranberry was 27.63 kJ/mol. The results indicated that the MAE process of anthocyanins was endothermic and controlled by mixing reaction and diffusion mechanism. The results provide a basis for industrial scale‐up and in‐depth study of anthocyanins in cranberry.Practical ApplicationsAnthocyanins are widely used as food colorants, antioxidants, and anticancer agents. Cranberry is rich in anthocyanins and can be used as a vital source of anthocyanins extraction. In this study, the extraction process for the microwave‐assisted extraction (MAE) of anthocyanins from cranberry was optimized using response surface methodology coupled with genetic algorithm to achieve of maximum anthocyanin yield, and the kinetic model of anthocyanins extraction from cranberry was established by plate model based on Fick's first Law, and the key model parameters (extraction rate constant and activation energy) were solved through the experimental results fitting.

Subcritical Water Extraction of Salvia miltiorrhiza

In this work, a green extraction technique, subcritical water extraction (SBWE), was employed to extract active pharmaceutical ingredients (APIs) from an important Chinese medicinal herb, Salvia miltiorrhiza (danshen), at various temperatures. The APIs included tanshinone I, tanshinone IIA, protocatechualdehyde, caffeic acid, and ferulic acid. Traditional herbal decoction (THD) of Salvia miltiorrhiza was also carried out for comparison purposes. Reproduction assay of herbal extracts obtained by both SBWE and THD were then conducted on Caenorhabditis elegans so that SBWE conditions could be optimized for the purpose of developing efficacious herbal medicine from Salvia miltiorrhiza. The extraction efficiency was mostly enhanced with increasing extraction temperature. The quantity of tanshinone I in the herbal extract obtained by SBWE at 150 °C was 370-fold higher than that achieved by THD extraction. Reproduction evaluation revealed that the worm reproduction rate decreased and the reproduction inhibition rate increased with elevated SBWE temperatures. Most importantly, the reproduction inhibition rate of the SBWE herbal extracts obtained at all four temperatures investigated was higher than that of traditional herbal decoction extracts. The results of this work show that there are several benefits of subcritical water extraction of medicinal herbs over other existing herbal medicine preparation techniques. Compared to THD, the thousand-year-old and yet still popular herbal preparation method used in herbal medicine, subcritical water extraction is conducted in a closed system where no loss of volatile active pharmaceutical ingredients occurs, although analyte degradation may happen at higher temperatures. Temperature optimization in SBWE makes it possible to be more efficient in extracting APIs from medicinal herbs than the THD method. Compared to other industrial processes of producing herbal medicine, subcritical water extraction eliminates toxic organic solvents. Thus, subcritical water extraction is not only environmentally friendly but also produces safer herbal medicine for patients.