Hot Compressed Water Extraction Research Articles

Cryo-Induced Cellulose-Based Nanogel from Elaeis guineensis for Antibiotic Delivery Platform.

Cryo-induced hydrogel from cellulose is a new class of biomaterials for drug delivery, cell delivery, bone and skin tissue engineering for cell proliferation and regeneration applications. This research aimed to synthesize cryo-induced hydrogel from cellulose and carboxymethyl cellulose (CMC) produced from empty bunch's cell wall of Elaeis guineensis. First, the experiment was to produce cellulose-rich material using hot-compressed water extraction followed by alkaline delignification and bleaching with H2O2. The obtained bleached EFB cellulose was used as the substrate for CMC, and the optimal condition with the highest degree of carboxyl substitution (DS) of 0.75 was achieved when varying NaOH and monochloroacetic acid concentration as well as etherification temperature using fractional factorial design. For cryogelation study, hydrogels were synthesized from cellulose, CMC and beta-cyclodextrin (β-CD) by dissolving cellulose-based matrix in a NaOH/urea system, and the cellulose (CEL) solution was frozen spontaneously at -40 °C followed by high speed mixing to loosen cellulose fibrils. Epichlorohydrin (ECH) and Polyethylene glycol diglycidyl ether (PEGDE) were used as a cross-linker. First, the ratio of cellulose and CMC with different amounts of ECH was investigated, and subsequently the proper ratio was further studied by adding different crosslinkers and matrices, i.e., CMC and β-CD. From the result, the ECH crosslinked CMC-CEL (E-CMC-CEL) gel had the highest swelling properties of 5105% with the average pore size of lyophilized hydrogel of 300 µm. In addition, E-CMC-CEL gel had the highest loading and release capability of tetracycline in buffer solution at pH 7.4 and 3.2. At pH 7.4, tetracycline loading and release properties of E-CMC-CEL gel were 65.85 mg g-1 dry hydrogel and 46.48 mg g-1 dry hydrogel (70.6% cumulative release), respectively. However, at pH 3.2, the loading and release capabilities of Tetracycline were moderately lower at 16.25 mg g-1 dry hydrogel and 5.06 mg g-1 dry hydrogel, respectively. The findings presented that E-CMC-CEL hydrogel was a suitable material for antibiotic tetracycline drug carrying platform providing successful inhibitory effect on Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, respectively.

Composition of Crude Palm Oil Extracted Using Hot Compressed Water Extraction.

Extraction process are one of the critical units in palm oil milling process which dictates its efficiency. In this study, hot compressed water extraction (HCWE) is utilized for the crude palm oil (CPO) extraction. With regards to CPO quality, the extracted CPO using HCWE was analysed based on overall composition, triacylglycerol (TAG) composition and fatty acid profile composition. This is to evaluate the possible product degradation during the process. From the results, the CPO extracted using HCWE process contain low FFA of 0.15±0.01% and low DAG of 2.145% which reflect to higher quality of CPO. This CPO also show the equal mixture of saturated and unsaturated fatty acid composition at 50.63% and 49.93% respectively, within the CPO composition range in the literature. No significant changing of the fatty acid composition is observed between CPO extracted using HCWE and commercial CPO indicated that no possible undesired reaction during the extraction process. HCWE is a promising method for screw press system replacement, but the economic analysis is essential to evaluate its prospective.

Physicochemical properties and biological activities of polysaccharides from the peel of Dioscorea opposita Thunb. extracted by four different methods

Polysaccharides are the important biologically active components found in the peel of Dioscorea opposita Thunb. (DTTP). The influences of 4 extraction methods, namely hot water extraction (W), acidic extraction (HA), hot-compressed water extraction (HCW) and enzyme-assisted extraction (EAE), on the yields, physicochemical properties, hypoglycemic and antioxidant activities of polysaccharides from DTTP were studied and compared. Among these DTTP polysaccharides, DTTP-HA was outstanding in several respects. DTTP-HA was the most water soluble; it had the highest total carbohydrate content (85.08 %), the highest uronic acid (13.20 %) and the highest thermal stability. DTTP-HA and DTTP-W possessed a triple-helix structure. These 4 kinds of polysaccharides have the same types of monosaccharides, but in different molar percentages. Extraction method had a significant impact on the microstructures of the extracted polysaccharides. DTT-HA exhibited irregular structure with many holes. Among the 4 extracted methods, the DTTP-HA and DTTP-W initially exhibited higher hypoglycemic and antioxidant activities. The better bioactivities of DTTP-HA may be related to the above factors. The findings indicated that acid extraction is an effective method to extract polysaccharides with high biological activities from DTTP.

Pectin polysaccharide from Flos Magnoliae (Xin Yi, Magnolia biondii Pamp. flower buds): Hot-compressed water extraction, purification and partial structural characterization

In this study, three novel and natural polysaccharides (FMP-1, FMP-2, and FMP-3) were obtained from Flos Magnoliae (FM, Xinyi in Chinese) using an efficient and green technique (hot-compressed water) for extraction and purified by DEAE-52 and Sephadex G-150. Their physicochemical properties, morphological and structural characteristics were investigated using chemical methods and instrumental analysis including methylation, partial acid hydrolysis, STA, GC-MS, HPGPC, HPAEC, FT-IR and NMR (1D and 2D). Results showed that FMPs all contained arabinose, rhamnose, galactose, xylose, mannose and galacturonic acid. FMP-2, with the highest yield and average molecular weight of the three (278.69 kDa), had large amounts of RG-I, minor amounts of HG with the molar ratio of 83.5:10.4, and trace amounts of RG-II domains. Thermal analys is exhibited that FMP-2 has a favorable thermal stability and it also exhibited effective antioxidant activities in a dose-dependent manner, which could be used as a potential stabilizer, thickening agent and natural antioxidant. These investigations provide a scientific basis for further investigation of FM polysaccharides in the context of their potential application in functional foods and medicines.

EFFECT OF TEMPERATURE ON RHEOLOGY BEHAVIOUR OF BANANA PEEL PECTIN EXTRACTED USING HOT COMPRESSED WATER

Banana peel pectin is extracted from banana peel waste using a hot compressed water extraction (140-160°C, 5 minutes, 1.18 mm particle size). Physicochemical contents of banana peel pectin were found to be in a similar range with commercial pectin, and is comprised of moisture (7.44-8.47%), ash (3.45-4.98%), protein (1.08-1.92%), fat (0.04-3.42), carbohydrate (83-86%), total sugar (1.77-3.41%), energy (353-369 kcal/100g) and specific heat (1.42-1.62 kJ/kg°C). These contents possibly related to their flow deformation of rheological behaviour. Regression analysis displayed good agreements in all models applied, apart from the Casson Model. Flow behaviour indices, n<1 and decreasing of apparent viscosity within increasing of shear rate indicates that banana peel pectin has excellent shear thinning behaviour with a presence of yield stress.

Crude palm oil (CPO) extraction using hot compressed water (HCW)

Abstract Hot compressed water extraction (HCWE) is a promising alternative technology which has proven to be successful in many applications. In this study, hot compressed water extraction (HCWE) was applied in the extraction of crude palm oil (CPO) from palm mesocarp. The operating conditions investigated were pressure of 30, 40 and 50 bar with varied temperature ranging from 120 to 180 °C through semi-batch extraction of 10 min interval and total extraction time of 60 min. The CPO yield, free fatty acids (FFA) content through HCWE process was analysed. Scanning electron microscopy (SEM) study on various palm mesocarp fibres undergone HCWE process at various conditions was also performed. The extracts formed three distinguished layers; oil, oil-water emulsion and water. The maximum CPO extracted in the oil layer was 0.541 ± 0.005 (g-oil/g-dried mesocarp) with averaged FFA of 0.81 ± 0.08% at the optimum operating condition of 160 °C and 50 bar. CPO recovered from the emulsion was 0.159 ± 0.004 g-oil/g-dried mesocarp giving a total CPO extracted at 0.700 ± 0.005 g-oil/g-dried mesocarp. SEM micrographs were used to assist understanding of the mechanism that took place during the experimental conditions of HCWE. The time dependence of the compounds was well represented by the second order mass transfer model. The mechanism of CPO extraction from palm mesocarp using HCWE was also explained through this study.

Hot compressed water extraction curve for palm oil and beta carotene concentration

Hot compressed water extraction (HCWE) is a promising green alternative for palm oil milling. The kinetic characteristic of HCWE for palm oil and it β-carotene concentration was experimentally investigated in this study at the different temperature and pressure. Semi-batch HCW extractor from 120 to 180 oC and 30 to 50 bar was used to evaluated the process for 60 mins of extraction in 10 mins interval. The results obtain using the HCWE process was compared with other extraction method. The oil extraction achieved the maximum extraction rate within 20 mins of extraction in most of the condition and starting to decrease until 60 mins of extraction time. The extraction rate for β-carotene was achieved the maximum rate in 10 mins and starting to decrease until 30 mins. None of β-carotene concentration had been extracted out from the palm oil mesocarp after 30 mins of extraction in all condition. The oil recovery of using HCWE was relatively low compare with the mechanical screw press, subcritical R134b, supercritical carbon dioxide and hexane extraction due to the oil loses in the oil-water emulsion. However, the β-carotene concentration in extracted oil using HCWE was improved compare with commercial crude palm oil (CPO) and subcritical R134a extraction.

Hot-compressed water extraction of polysaccharides from soy hulls

The polysaccharides of soy hulls were extracted by hot-compressed water at temperatures of 110 from 180°C and various treatment times (10–150min) in a batch system. It was determined that a moderate temperature and short time are suitable for the preparation of polysaccharides. The structure of xylan and the inter- and intra-chain hydrogen bonding of cellulose fibrils in the soy hulls were not significantly broken down. The polysaccharides obtained were primarily composed of α-l-arabinofuranosyl units, 4-O-methyl-glucuronic acid units and α-d-galactose units attached with substituted units. A sugar analysis indicated that arabinose was the major component, constituting 35.6–46.9% of the polysaccharide products extracted at 130°C, 140°C, and 150°C. This investigation contributes to the knowledge of the polysaccharides of soy by-products, which can reduce the environmental impact of waste from the food industries.

Modeling and Optimization of the Hot Compressed Water Extraction of Palm Oil Using Artificial Neural Network

Hot compressed water extraction (HCWE) is a promising green alternative to the screw press in the palm oil processing. In this study, the steady-state characteristic of the HCWE was modeled by using an artificial neural network (ANN). The overall oil yield and other outputs; β-carotene, α-tocopherol and α-tocotrienol concentration, were described by the pressure and temperature in the HCWE. The results show that the predicted yield and concentrations agree well with experimental data. These models were used to estimate the optimum conditions of the HCWE process.

Hot Compressed Water Extraction of Lignin by Using a Flow-Through Reactor

Japanese rice straw, an agricultural by-product, was utilized for the extraction of lignin by hot compressed water at temperatures of 443–503 K and a pressure of 4.0 MPa using a flow-through system, a simple and environmentally friendly extraction method requiring no chemicals other than water. Under these conditions, thermal softening of the Japanese rice straw occurred, allowing the removal of lignin via depolymerization reactions. Lignin as an extraction product was analyzed using utraviolet-visible (UV–vis) spectrophotometry. Lignin recovery approached 85 % when the extraction was performed at 443 and 473 K with a flow rate of 4.67 ml min–1. At a constant residence time, recovery amounts increased with increasing flow rate at each temperature. The results suggested that this process may result in an advanced plant biomass components extraction technology.

Estimation of ginger bioactive compound solubilities in hot compressed water and enhancement with entrainer

Knowledge concerning the solubility of ginger bioactive compounds in hot compressed water (HCW) is important for designing an extraction process with water as a green solvent. The solubilities of 6-gingerol and 6-shogaol in hot compressed water are calculated using the conductor-like screening model for real solvent (COSMO-RS) method to study the potential of water as a solvent. The comparison indicates that the calculated solubility is at a higher concentration for the binary system of 6-gingerol+water and 6-shogaol+water when compared to the HCW extraction. This illustrates the performance of the HCW extraction, which has not reached the equilibrium condition, and gives an opportunity to explore the options for further improving the process. The availability as well as the thermo-labile nature of the bioactive compounds are factors that must be considered for the improvement of HCW as a solvent. The solubilities of 6-gingerol and 6-shogaol in aqueous ethanol solutions are also calculated by the COSMO-RS method to study the entrainer effect of ethanol. The calculations with ethanol as entrainer indicate that the molecular cavity and contact interaction are changed so as to increase the solubilities. Based on the calculations, the suitable amount of ethanol as an entrainer is estimated to be 0.02mole fraction for both 6-gingerol and 6-shogaol with an improved solubility of 1.86 and 1.76 times, respectively. In general, the addition of the entrainer will improve the recovery and operating parameters at a milder operating condition. This approach may be applied to other bioactives and will further strengthen the use of water as a solvent in natural extracts.

The kinetics of extraction of the medicinal ginger bioactive compounds using hot compressed water

Zingiber officinale or ginger known for its high medicinal compounds is extracted using hot compressed water (HCW). The two most important bioactive compounds namely 6-gingerol and 6-shogaol in the ginger extracts are analyzed using HPLC. The effects of temperature and time of extraction on 6-gingerol and 6-shogaol are studied using HCW extraction. It is found that HCW extraction can extract these two bioactive compounds; 6-gingerol at 130°C and 30min whilst 6-shogaol at 170°C and 20min. This finding shows that HCW extraction is potentially used in selective extraction of bioactive compounds at different conditions of HCW. The kinetics of extraction for both bioactive compounds is studied from the optimum temperatures obtained. The overall mass transfer coefficient which represents the extraction efficiency is calculated using mass transfer model. The optimum values of the overall mass transfer coefficient (k) for 6-gingerol is 8×10−7m/s at 130°C whilst for 6-shogaol, is 18×10−7m/s at 170°C using HCW extraction. The relationship between the overall mass transfer coefficient and the dielectric constant of various solvents for 6-gingerol is identified. Similar relationship is identified for 6-shogaol using HCW as solvent. The dielectric constant does not contribute to the extraction efficiency of 6-gingerol and 6-shogaol.

Hot compressed water extraction of polysaccharides from Ganoderma lucidum using a semibatch reactor

ABSTRACTGanoderma lucidum (G. lucidum) is a mushroom‐forming white rot fungus. Although not edible, it is grown commercially for use as a medicinal supplement. In this study, G. lucidum was utilized for the extraction of polysaccharides by hot compressed water at temperatures of 373–463 K and a pressure of 4.0 MPa using a semibatch system—a most effective method because water at high temperature and pressure behaves as a reaction medium with remarkable properties. Under these conditions, thermal softening of G. lucidum occurred, allowing the removal of the polysaccharides protecting other constituents in G. lucidum via hydrolysis. The main massed peaks of water‐soluble products were distributed at around 688–2638 m/z with a peak‐to‐peak mass difference of 162 m/z, consistent with the repeating unit of the glucans. On the basis of these results, this process is proposed as applicable to the isolation of polysaccharides from other types of biomass and may lead to an advanced plant biomass components extraction technology. © 2013 Curtin University of Technology and John Wiley & Sons, Ltd.