Subcritical water extraction of phytochemicals from Phlomis umbrosa Turcz

Ko, M.J.,Lee, J.H.,Nam, H.H.,Chung, M.S. ELSEVIER 2017 INNOVATIVE FOOD SCIENCE AND EMERGING TECHNOLOGIES Vol. No.

<P>Subcritical water extraction (SWE) avoids the use of organic solvents when extracting active compounds. The SWE of phytochemicals from Phlomis umbrosa Turcz (PT) and the effect of antioxidant activity were investigated while varying the extraction temperature (from 100 degrees C to 200 degrees C) and time (from 5 to 25 min). The maximum yields of total polyphenols (142.02 +/- 5.67 mg/g PT, mean SD) and flavonoids (33.69 +/- 3.01 mg/g PT) were obtained for an extraction temperature and time of 200 degrees C and 20 min, respectively. The correlation of antioxidant activities in terms of their total phenolics and flavonoids contents suggest that the ABTS.(+) assay better reflects the antioxidant contents in SWE from PT than does the DPPH assay for extraction temperatures from 110 degrees C to 200 degrees C. At higher temperatures around 200 degrees C, SWE extracts affect the antioxidant activity due to the presence of not only flavonoids but also nonflavonoid phenolic compounds including prenylated flavonoids. Industrial relevance: This study used subcritical water extraction (SWE) for the practical applications of the SWE process that extracts antioxidant compounds from medicinal herb such as Phlomis wnbrosa Turcz. SWE is excellent technology to selectively extract bioactive compounds using temperature-dependent dielectric constant properties of water. As the temperature of water is increased, the polarity of water decreases. That's why it is selective extraction. The use of SWE in the present study was associated with high efficiency and antioxidant activities. These results indicate that SWE is an efficient and rapid method for extracting phytochemicals, and a safer product only using purified water. SWE has a potential to develop a commercial process for the extraction of phytochemicals. This method can be easily implemented on an industrial scale.</P>

Remediation of PAHs contaminated soil by extraction using subcritical water

Mohammad Nazrul Islam,조영태,박정훈 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.5

The remediation of polycyclic aromatic hydrocarbons (PAHs) contaminated soil has been investigated by extraction using continuous flowing subcritical water. Water temperature ranging from 100 to 300 8C,extraction time ranging from 15 to 60 min, and flow rate ranging from 0.5 to 2.0 mL/min were investigated to determine their effect on the removal efficiencies of target PAHs. More than 95%extraction of the phenanthrene, fluoranthene, and pyrene from contaminated soil was observed at 300 8C for 30 min and 250 8C for 60 min at a constant pressure of 100 bar. However, naphthalene was almost completely extracted only at a comparatively low temperature of 150 8C and extraction time of up to 30 min and a pressure of 100 bar. The subcritical water flow rate of 0.5 mL/min was recommendable in this study. The extraction efficiency of PAHs was extremely dependent on water temperature, since the dielectric constant (polarity) of water could be dramatically lowered by raising the water temperature. These results suggest that soils contaminated by persistent organic chemicals such as PAHs can be easily remediated by extraction using pure water under a high temperature without any modification.

Remediation of PAHs contaminated soil by extraction using subcritical water

Islam, M.N.,Jo, Y.T.,Park, J.H. Korean Society of Industrial and Engineering Chemi 2012 Journal of industrial and engineering chemistry Vol.18 No.5

The remediation of polycyclic aromatic hydrocarbons (PAHs) contaminated soil has been investigated by extraction using continuous flowing subcritical water. Water temperature ranging from 100 to 300<SUP>o</SUP>C, extraction time ranging from 15 to 60min, and flow rate ranging from 0.5 to 2.0mL/min were investigated to determine their effect on the removal efficiencies of target PAHs. More than 95% extraction of the phenanthrene, fluoranthene, and pyrene from contaminated soil was observed at 300<SUP>o</SUP>C for 30min and 250<SUP>o</SUP>C for 60min at a constant pressure of 100bar. However, naphthalene was almost completely extracted only at a comparatively low temperature of 150<SUP>o</SUP>C and extraction time of up to 30min and a pressure of 100bar. The subcritical water flow rate of 0.5mL/min was recommendable in this study. The extraction efficiency of PAHs was extremely dependent on water temperature, since the dielectric constant (polarity) of water could be dramatically lowered by raising the water temperature. These results suggest that soils contaminated by persistent organic chemicals such as PAHs can be easily remediated by extraction using pure water under a high temperature without any modification.

Pilot-scale subcritical water extraction of flavonoids from satsuma mandarin (Citrus unshiu Markovich) peel

Ko, M.J.,Kwon, H.L.,Chung, M.S. Elsevier Science 2016 INNOVATIVE FOOD SCIENCE AND EMERGING TECHNOLOGIES Vol. No.

The effects of operating parameters (extraction temperature, extraction time, material type, solute/solvent ratio, and pressure) on the subcritical water extraction of flavonoids from dried satsuma mandarin peel were studied. From the practical aspect, the optimum conditions for obtaining flavonoids by pilot-scale subcritical water extraction were as follows: extraction temperature of 130<SUP>o</SUP>C, extraction time of 15min, and solute/solvent ratio of 1/34. The yields of flavonoids obtained under laboratory and pilot conditions were similar: 117.8 and 113.4mg/g satsuma mandarin peel, respectively. The proportion of flavonoids recovered by subcritical water extraction in the pilot plant was 96.3%, and large-scale experiments using this method demonstrate its potential industrial applications. Industrial relevance: This study used a pilot-scale subcritical water extraction (SWE) plant (8L scale) for the scale-up and commercialization of the SWE process that extracts antioxidant flavonoids from agricultural by-products such as Citrus unshiu Markovich. SWE is excellent technology to selectively extract flavonoids using temperature-dependent dielectric constant properties of water. The flavonoid yield from the pilot-scale SWE was similar to that obtained from laboratory-scale SWE. These results indicate that SWE is an efficient and rapid method for extracting flavonoids, and a safer product only using purified water. This method can be easily implemented on an industrial scale.

The feasibility of recovering oil from contaminated soil at petroleum oil spill site using a subcritical water extraction technology

Islam, Mohammad Nazrul,Jung, Sun-Kook,Jung, Ho-Young,Park, Jeong-Hun Elsevier 2017 PROCESS SAFETY AND ENVIRONMENTAL PROTECTION Vol.111 No.-

<P><B>Abstract</B></P> <P>The effective disposal of oily solid waste has received widespread attention due to its complex combination of various petroleum hydrocarbons, water, heavy metals and solid particles. Removal/recovering oil from such waste can be a feasible option. In this study, a subcritical water extraction (SWE) process was used to remove and recover oil from oil-contaminated soil. Under the experimental conditions (90min extraction at 260°C at the gauge pressure of 8MPa and the water-to-soil ratio of 3:1), we achieved an oil removal efficiency of about 86% in the soil residue after extraction and we recovered approximately 39% of the oil. The possible presence of organic compounds in the recovered oil indicated by Fourier transform infrared spectroscopy (FTIR) spectra was consistent with the gas-chromatography and mass spectrometry (GC–MS) analysis, which was composed of various aromatic and aliphatic hydrocarbons. The physicochemical properties and heavy metal content of the recovered oil were also measured. The fuel characteristics of the recovered oil had similar fuel characteristics as commercial crude oil. These characteristics included density, specific gravity, element composition and heating value. The results showed that SWE treatment has the potential to remove and recover oil from oily contaminated soil.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Subcritical water was used to remove and recover oil from contaminated soil. </LI> <LI> Performance of subcritical water extraction at 260°C in the removal of TPH was 86%. </LI> <LI> Another promising result was the oil recycling rate of 39%. </LI> <LI> Subcritical water extraction process recovered worth quality oil. </LI> <LI> This technique is useful for both oil recovery and solid disposal approaches. </LI> </UL> </P>

배치형과 연속흐름형에 의한 토양 중 RDX의 아임계 분해특성 비교연구

최재헌,이환,이철효,김주엽,박정훈,조영태,Choi, Jae-Heon,Lee, Hwan,Lee, Cheol-Hyo,Kim, Ju-Yup,Park, Jeong-Hun,Jo, Young-Tae 한국지하수토양환경학회 2015 지하수토양환경 Vol.20 No.6

The purpose of this study is to compare the degradation characteristics by subcritical water of RDX contaminated soil using batch mode and dynamic mode devices. First, upon application of RDX contaminated soil, RDX treatment efficiency was increased with increasing the temperature in both modes. At 150℃, the treatment efficiency was 99.9%. RDX degradation efficiency got higher with lower ratio of solid to liquid. However, the treatment efficiency in the dynamic mode tended to be decreased at a certain ratio of solid to liquid or lower. The treatment efficiency was increased when it took longer time for the reactions in both modes. As the results of analysis on concentration of treated water after subcritical water degradation, the RDX recovery rate of dynamic and batch modes at 150℃ was 10.5% and 1.5%, respectively. However, both modes showed very similar recovery rates at 175℃ or higher. RDX degradation products were analyzed in treated water after it was treated with subcritical water. According to the results, RDX degradation mechanism was mostly oxidation reaction and reduction reaction was partially involved. Therefore, it suggested that most of RDX in soil was degraded by oxidation of subcritical water upon extraction. According to this result, it was found that both batch and dynamic modes were very effectively applied in the treatment of explosive contaminated soil.

Effects of Soy Protein Hydrolysates Prepared by Varying Subcritical Media on the Physicochemical Properties of Pork Patties

이윤경,고보배,Munkhtugs Davaatseren,홍근표 한국축산식품학회 2016 한국축산식품학회지 Vol.36 No.1

This study investigated the effect of soy protein hydrolysates (SPH) prepared by varying subcritical media on the physicochemical properties of pork patties. For resource of SPH, two different soybean species (Glycine max Merr .) of Daewonkong (DWK) and Saedanbaek (SDB) were selected. SPH was prepared by subcritical processing at 190ºC and 25 MPa under three different of media (water, 20% ethanol and 50% ethanol). Solubility and free amino group content revealed that water was better to yield larger amount of SPH than ethanol/water mixtures, regardless of species. Molecular weight (Mw) distribution of SPH was also similar between two species, while slightly different Mw distribution was obtained by subcritical media. For pork patty application, 50% ethanol treatment showed clear red color comparing to control after 14 d of storage. In addition, ethanol treatment had better oxidative stability than control and water treatment based on thiobarbituric acid-reactive substances (TBARS) analysis. For eating quality, although 20% ethanol treatment in SDB showed slightly higher cooking loss than control, generally addition of SPH did not affect the water-binding properties and hardness of pork patties. Consequently, the present study indicated that 50% ethanol was the best subcritical media to produce SPH possessing anti-oxidant activity, and the SPH produced from DWK exhibited better antioxidant activity than that produced SDB.

Effects of Soy Protein Hydrolysates Prepared by Varying Subcritical Media on the Physicochemical Properties of Pork Patties

Lee, Yun-Kyung,Ko, Bo-Bae,Davaatseren, Munkhtugs,Hong, Geun-Pyo Korean Society for Food Science of Animal Resource 2016 한국축산식품학회지 Vol.36 No.1

This study investigated the effect of soy protein hydrolysates (SPH) prepared by varying subcritical media on the physicochemical properties of pork patties. For resource of SPH, two different soybean species (Glycine max Merr.) of Daewonkong (DWK) and Saedanbaek (SDB) were selected. SPH was prepared by subcritical processing at 190℃ and 25 MPa under three different of media (water, 20% ethanol and 50% ethanol). Solubility and free amino group content revealed that water was better to yield larger amount of SPH than ethanol/water mixtures, regardless of species. Molecular weight (Mw) distribution of SPH was also similar between two species, while slightly different Mw distribution was obtained by subcritical media. For pork patty application, 50% ethanol treatment showed clear red color comparing to control after 14 d of storage. In addition, ethanol treatment had better oxidative stability than control and water treatment based on thiobarbituric acid-reactive substances (TBARS) analysis. For eating quality, although 20% ethanol treatment in SDB showed slightly higher cooking loss than control, generally addition of SPH did not affect the water-binding properties and hardness of pork patties. Consequently, the present study indicated that 50% ethanol was the best subcritical media to produce SPH possessing antioxidant activity, and the SPH produced from DWK exhibited better antioxidant activity than that produced SDB.

Effects of Ethanol Addition on the Efficiency of Subcritical Water Extraction of Proteins and Amino Acids from Porcine Placenta

Park, Sung Hee,Kim, Jae-Hyeong,Min, Sang-Gi,Jo, Yeon-Ji,Chun, Ji-Yeon Korean Society for Food Science of Animal Resource 2015 한국축산식품학회지 Vol.35 No.2

In a previous study, hydrolysates of porcine placenta were obtained and the extraction efficiency for proteins and amino acids was compared between sub- and super-critical water extraction systems; optimum efficiency was found to be achieved using subcritical water ($170^{\circ}C$, 10 bar). In this study, the effects of adding ethanol to the subcritical water system were investigated. The lowest-molecular-weight extraction product detected weighed 434 Da, and the efficiency of extraction for low-molecular-weight products was increased when either the concentration of ethanol was decreased, or the extraction time was lengthened from 10 min to 30 min. The highest concentration of free amino acids (approximately 8 mM) was observed following 30 min extraction using pure distilled water. The concentration of free amino acids was significantly lower when ethanol was added or a shorter extraction time was used (p<0.05). Color change of the solution following extraction was measured. There were no significant differences in color between lysates produced with different extraction times when using distilled water (p>0.05); however, using different extraction times produced significant differences in color when using 20% or 50% ethanol solution for subcritical extraction (p<0.05). The range of pH for the hydrolysate solutions was 6.4-7.5. In conclusion, the investigated extraction system was successful in the extraction of $\leq$ 500 Da hydrolysates from porcine placenta, but addition of ethanol did not yield higher production of low-molecular-weight hydrolysates than that achieved by DW alone.

Effects of Ethanol Addition on the Efficiency of Subcritical Water Extraction of Proteins and Amino Acids from Porcine Placenta

박성희,김재형,민상기,조연지,천지연 한국축산식품학회 2015 한국축산식품학회지 Vol.35 No.2

In a previous study, hydrolysates of porcine placenta were obtained and the extraction efficiency for proteins and amino acids was compared between sub- and super-critical water extraction systems; optimum efficiency was found to be achieved using subcritical water (170°C, 10 bar). In this study, the effects of adding ethanol to the subcritical water system were investigated. The lowest-molecular-weight extraction product detected weighed 434 Da, and the efficiency of extraction for low-molecular-weight products was increased when either the concentration of ethanol was decreased, or the extraction time was lengthened from 10 min to 30 min. The highest concentration of free amino acids (approximately 8 mM) was observed following 30 min extraction using pure distilled water. The concentration of free amino acids was significantly lower when ethanol was added or a shorter extraction time was used (p<0.05). Color change of the solution following extraction was measured. There were no significant differences in color between lysates produced with different extraction times when using distilled water (p>0.05); however, using different extraction times produced significant differences in color when using 20% or 50% ethanol solution for subcritical extraction (p<0.05). The range of pH for the hydrolysate solutions was 6.4-7.5. In conclusion, the investigated extraction system was successful in the extraction of ≤ 500 Da hydrolysates from porcine placenta, but addi- tion of ethanol did not yield higher production of low-molecular-weight hydrolysates than that achieved by DW alone.