MOLECULES
·
2023
·Vol. 28
·期 6
·2591
·
IF 4.6
Longlong Liu,Hua Zhang
Silymarin and milk thistle oil have unique biological benefits; however, applying silymarin to milk thistle oil remains a challenge. In this research, the content of silymarin in milk thistle oil conditions using enzyme-mediated solvent extraction was investigated and optimized by response surface methodology. The optimal extraction conditions using enzyme-mediated solvent extraction were as follows: the enzyme-added content was 3.06 mg/mL, the enzymatic hydrolysis temperature was 55.09 °C, and the enzymatic hydrolysis time was 66.28 min. Oil extracted by the enzyme-mediated assisted solvent was further compared with those extracted with n-hexane and cold pressing. Results indicated that the oil extraction using the enzyme-mediated assisted solvent had a lower acid value (2.20 ± 0.01 mg/g) and the highest α-tocopherol content (0.62 ± 0.00 mg/g), total phenols (7.67 ± 0.01 mg/g), and flavonoids (1.06 ± 0.13 mg/g). Furthermore, the antioxidant capacity of milk thistle oils was further investigated. The results showed that the enzyme-mediated assisted solvent-extracted oil had the strongest antioxidant capacity with lower lipid oxide content. Therefore, enzyme-mediated solvent extraction is an excellent method for extracting milk thistle oil.Keywords:milk thistle oil;silymarin;response surface methodology;antioxidant properties
研究领域:
植物学
·
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Arabian Journal of Chemistry
·
2023
·
IF 6
Haijun Cheng,Min Liang,Suyi Dai,Xianrui Lu,Qilin Huang,Fang Lai,Li Ma,Weiguang Li,Xiongmin Liu
α-Pinene, β-pinene and turpentine are renewable resources that are widely used in fine chemicals, fuels and other applications, and the safety of their production, transport and use should be considered. In this work, the characteristics and hazardous of the oxidation process of α-pinene, β-pinene and turpentine were investigated by using a novel mini closed pressure vessel testing system (MCPVT). The oxidation products were resolved by gas chromatography-mass spectrometry (GC–MS). The results showed that α-pinene, β-pinene and turpentine were stable under nitrogen atmosphere and very active chemically under oxygen atmosphere. The activation energies ( E a ) of α-pinene, β-pinene and turpentine were calculated to be 78.87, 109.69 and 98.82 kJ/mol, respectively, using pressure–time (P-t) curves. So, the reaction activity sequence was α-pinene > turpentine > β-pinene. The peroxide concentrations of α-pinene (363 K), β-pinene (358 K) and turpentine (363 K) could reach 81.94, 84.70 and 75.76 mmol/kg, respectively, at relatively low temperatures. 0.6 g of α-pinene exploded at a system temperature of 369 K and an oxygen pressure of 1.23 MPa. 0.6 g of β-pinene also exploded at a system temperature of 373 K and an oxygen pressure of 1.27 MPa. 0.4 g of turpentine experienced thermal runaway at a system temperature of 384 K and an oxygen pressure of 0.81 MPa. The major oxidation products of α-pinene are α-campholenaldehyde, laevo-pinocarveol, verbenol, verbenone, bicyclo (3.1.1)heptane-2, 3-diol, 2, 6, 6-trimethyl, 2-cyclohexen-1-ol, 2-methyl-5-(1-methylethenyl)-, (1R,5R)-rel-, cyclobutaneacetic acid, 3-acetyl-2, 2-dimethyl, myrtenol and myrtenal. The major thermal runaway products are water, ethanol, acetone, acetic acid, 2-pentanone, propyl acetate, toluene, cymene and methylacetophenone. The major oxidation products of β-pinene are nopinone, laevo-pinocarveol, pinocarvone, myrtenol, myrtenal and perillyl alcohol. The major thermal runaway products are water, ethanol, acetone, n-ethyl propanoate, toluene, butyl acetate, cymene, apocamphor, nopinone, bornyl formate, methylacetophenone and dihydronopol. The oxidation products and thermal runaway products of pinene were significantly different. Possible reaction pathways for α-pinene and β-pinene are proposed.
研究领域:
化学工程
·
安全科学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2025
·Vol. 30
·期 5
·1161
·
IF 4.6
Jia Fang,Kejian Wang,Peng Chen,Xilong Xu,Chengzhuang Zhang,Yi Wu,Yan Yan,Zinong Zuo
In this study, a series of cerium dioxide catalysts with varying hydrothermal temperatures and times were synthesized using the hydrothermal method, without the use of templates. The impact of varying hydrothermal conditions on the activity of cerium dioxide catalysts was investigated through experiments to examine their oxidation characteristics in soot combustion. Among the conditions tested, the hydrothermal conditions of 140 °C and 6 h yielded the most optimal catalytic oxidation of soot, with a combustion characteristic temperature ( T p ) of 552 °C and a reduction of 122.9 °C. The integrated combustion index ( S ) and combustion stability coefficient ( R w ) were found to be 27.97 × 10 8 % 2 min −2 °C −3 and 90.76 × 10 5 , respectively. The indices of S and R w exhibited an improvement of 51.1% and 36.93%, respectively.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Qifang Zheng,Liuyang Dong,Peilun Shen,Dianwen Liu
Magnetic separation poses challenges for the effective separation of chalcopyrite and pyrrhotite. Therefore, flotation separation has emerged as a key research focus. This study investigated the oxidative properties and flotation behavior associated with the separation of chalcopyrite and pyrrhotite using sodium periodate (NaIO 4 ). The results of flotation test show that without adding depressant, the recovery of chalcopyrite and pyrrhotite were 91.57 % and 90.15 %, respectively. When addition of 1 × 10 –3 mol/L NaIO 4 and 1 × 10 –4 mol/L potassium butyl xanthate, chalcopyrite and pyrrhotite achieved recovery of 88.25 % and 15.41 %, respectively. This effectively promoted the flotation separation of the two minerals. The NaIO 4 oxidation reduced pyrrhotite’s surface hydrophobicity by forming hydrophilic species. The S 2– and Fe 2+ species on the pyrrhotite surface were oxidized to hydrophilic SO 4 2– and Fe 3+ species, potentially forming FeOOH – species and sulfate films that hindered collector adsorption. However, the S 2– species on the chalcopyrite surface were oxidized to hydrophobic S 0 /S n 2– , enabling the mineral to maintain its good floatability. Moreover, a descriptive model was developed to illustrate the different oxidative properties of both chalcopyrite and pyrrhotite treated with NaIO 4 . This study provides a new approach for the efficient enrichment and utilization of pyrrhotite.
研究领域:
矿物加工工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 8
·1733
·
IF 4.2
Shuo Zhang,Ze Liu,Xinyu Xu,Ruihua Zhao,Shujiang Zhang,Rong Luo
In traditional Chinese medicine, Aurantii Fructus Immatures (AFIs) have been utilized for more than 2000 years. The proportions of different fruit parts are crucial for evaluating AFI quality in China. However, the basis for this statement’s substance is unclear. Differences in quality are intimately correlated with a plant’s metabolite composition. On the basis of a widely targeted metabolome, this study intended to investigate the metabolite composition and evaluate the antioxidant capacity of the peel and pulp of an AFI. Metabolites were identified and quantified by UHPLC-QqQ-MS. To assess their antioxidant ability, DPPH and ABTS assays were carried out. There were 1327 chemical compounds identified by UHPLC-QqQ-MS. After screening the differential metabolites using a multivariate statistical analysis, it was found that there were 695 significant differences in the metabolites between the peel and the pulp. Among them, it was discovered that the content of active ingredients in the peel group was higher than that in the pulp group. Furthermore, the aqueous extracts from the peel showed stronger antioxidant capacities than those from the pulp. The metabolites and antioxidant capacities were significantly different between the peel and the pulp. This study of different fruit parts might provide a guide for AFI quality assessments.
研究领域:
药理学
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中药学
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代谢组学
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植物科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2021
·Vol. 29
·期 3
·521-528
·
IF 2.232
Wang Yu,Zhang Guohua,Chou Kuochih
ZrC and ZrB 2 are both typical ultra-high temperature ceramics, which can be used in the hyperthermal environment. In this study, a method for preparing ultrafine ZrC-ZrB 2 composite powder was provided, by using the raw materials of nano ZrO 2 , carbon black, B 4 C, and metallic Ca. It is worth pointing out that ZrC-ZrB 2 composite powder with any proportion of ZrC to ZrB 2 could be synthesized by this method. Firstly, a mixture of ZrC and C was prepared by carbothermal reduction of ZrO 2 . By adjusting the addition amount of B 4 C, ZrC was boronized by B 4 C to generate ZrC-ZrB 2 composite powder with different compositions. Using this method, five composite powders with different molar ratios of ZrC and ZrB 2 (100ZrC, 75ZrC-25ZrB 2 , 50ZrC-50ZrB 2 , 25ZrC-75ZrB 2 , and 100ZrB 2 ) were prepared. When the temperature of boronization and decarburization process was 1473 K, the particle size of product was only tens of nanometres. Finally, the oxidation characteristics of different composite powders were investigated through oxidation experiments. The oxidation resistance of ZrC-ZrB 2 composite powder continued to increase as the content of ZrB 2 increased.
研究领域:
材料科学
·
陶瓷
·
高温材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PLANT GROWTH REGULATION
·
2022
·Vol. 42
·期 3
·1937-1952
·
IF 4.64
Cheng Siren,Fang Zhenming,Cheng Xianchao,Wu Yizhu,Mo Lifang,Yan Chongyang,Zhou Langshan,Ren Yong
Despite copper (Cu) being an essential nutrient for the growth and development of all living organisms, the yield and tolerance mechanisms of fragrant rice under Cu-induced stress have not been reported. In this study, we tested two fragrant rice cultivars (Meixiangzhan and Yuxiangyouzhan) at the heading stage, with four Cu doses (CuSO 4 ·5H 2 O), i.e., 0 (CK), 20 (T1), 40 (T2), and 60 mM (T3) in a pot experiment. Our results showed that T2 treatment improved the yield of Meixiangzhan and Yuxiangyouzhan by 8.33% and 18.51%, respectively, by improving grains per panicle and the seed-setting rate. Moreover, Yuxiangyouzhan had the highest yield in T2 treatment, indicating that it had better Cu-tolerance than Meixiangzhan. Both cultivars had a similar response to Cu dose treatments. While T1 and T2 improved leaf pigment contents, antioxidant enzyme activities, and soluble protein content in plant tissues, T3 treatment instead promoted higher malondialdehyde (MDA) content accumulation and regulated antioxidant attributes. Overall, low-level Cu dosing significantly improved the fragrant rice yield via modulation of the antioxidant attributes. Therefore, this study provides supporting evidence for utilizing Cu reagent or assessing Cu toxicity in fragrant rice.
研究领域:
植物科学
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农学
·
环境胁迫
✓ 已验证
产品关联
DOI
高影响因子
BMC Chemistry
·
2023
·Vol. 17
·期 1
·1-17
·
IF 4.6
Liang Min,Dai Suyi,Cheng Haijun,Yu Chang,Li Weiguang,Lai Fang,Yang Kang,Ma Li,Liu Xiongmin
In this study, the oxidation characteristics of isoprene were investigated using a custom-designed mini closed pressure vessel test (MCPVT). The results show that isoprene is unstable and polymerization occurs under a nitrogen atmosphere. Under an oxygen atmosphere, the oxidation process of isoprene was divided into three stages: (1) isoprene reacts with oxygen to produce peroxide; (2) Peroxides produce free radicals through thermal decomposition; (3) Free radicals cause complex oxidation and thermal runaway reactions. The oxidation of isoprene conforms to the second-order reaction kinetics, and the activation energy was 86.88 kJ·mol −1 . The thermal decomposition characteristics of the total oxidation product and purified peroxide mixture were determined by differential scanning calorimetry (DSC). The initial exothermic temperatures T on were 371.17 K and 365.84 K, respectively. And the decomposition heat Q DSC were 816.66 J·g −1 and 991.08 J·g −1 , respectively. It indicates that high concentration of isoprene peroxide has a high risk of thermal runaway. The results of thermal runaway experiment showed that the temperature and pressure of isoprene oxidation were prone to rise rapidly, which indicates that the oxidation reaction was dangerous. The reaction products of isoprene were analyzed by gas chromatography-mass spectrometry (GC–MS). The main oxidation products were methyl vinyl ketone, methacrolein, 3-methylfuran, etc. The main thermal runaway products were dimethoxymethane, 2,3-pentanedione, naphthalene, etc. Based on the reaction products, the possible reaction pathway of isoprene was proposed.
研究领域:
化学工程
·
安全科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Dongxing Wang,Ying Wang,Xiaochen Wang,Funan Guo,Yuanqi Bai
As a promising alternative fuel with favorable properties and attractive prospects, the application of n-hexanol in diesel engines has aroused the interest of researchers. This study investigated the effects of mixing with n-hexanol on the morphology, nanostructure, graphitization, and oxidation reactivity of soot particles generated from a diesel engine. Experiments were performed on a turbocharged, four-cylinder direct-injection diesel engine fueled with D100 (neat diesel fuel), DH15 (15% n-hexanol and 85% diesel, v/v), and DH30 (30% n-hexanol and 70% diesel, v/v), respectively. Under the constant torque of 125 N·m, two typical speeds of 1370 and 2150 rpm were selected. Transmission electron microscopy (TEM), Raman spectroscopy (RS), and thermogravimetric analysis (TGA) were used to characterize particulate samples. TEM images showed that DH15 and DH30 particles had smaller primary particle diameters in comparison with neat diesel particles. Moreover, with the increase of the n-hexanol content in mixtures, the interlayer distance increased, indicating a more disordered nanostructure. RS results showed that soot samples generated from n-hexanol/diesel blended fuels had a lower degree of graphitization with larger ID1/IG and AD1/AG and more amorphous carbon with larger ID3/IG and AD3/AG. Based on TGA, it can be deduced that the DH30 soot sample obtained at the engine speed of 1370 rpm was easier to be oxidized in the DPF regeneration process for an 8.23% reduction in Tmax compared with D100 soot. Furthermore, activation energy of soots sampled at the engine speed of 2150 rpm decreased from 123.0 kJ/mol for D100 soot, to 109.6 kJ/mol for DH15 soot, and to 101.2 kJ/mol for DH30 soot, respectively. Regarding the effect of engine speeds on physicochemical characteristics of particles, results showed that the soot has higher oxidation activity under higher engine speed.
研究领域:
能源与燃料
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Haiwei Ren,Danni Peng,Meiqi Liu,Yizhen Wang,Zhijuan Li,Hongyuan Zhao,Yi Zheng,Yuan Liu,Xiaoxiao Feng
In order to elucidate the dynamic changes of quality characteristics in Xanthoceras sorbifolium leaf tea (XLT), this work investigated the chemical components, volatile profile, and antioxidant properties at key stages of fixation, shaping, and drying. The process of fixation and drying emerged as critical stages that affected the chemical components and taste of XLT. Total polyphenols, reducing sugars and chlorophyll were the differential compounds, which decreased by 29.1 %, 63.3 % and 69.5 % during processing, respectively. Threonine, glycine, arginine, reducing sugar, caffeine, catechin (C), and epicatechin gallate (ECG) were primary taste characteristic compounds. A total of 95 volatile organic components (VOCs) and 24 key odorants with relative odor activity value (ROAV) > 1.0 were identified in XLT, ethyl 2-methylbutanoate-D, dimethyl disulfide, and ethyl isobutyrate (ROAV = 100) were the central contributors to volatiles profile. Moreover, tea manufacturing enhanced the antioxidant potency composite (APC) by 1.1 %, primarily due to its high water extract content.
研究领域:
食品科学
·
植物学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE
·
2021
·Vol. 59
·期 2
·445-455
·
IF 2.701
Liu Longlong,Lin Jun,Chen ZhiYu,Zhang Hua,Li Jing
The gel was prepared by thermal induction of egg yolk powder as raw material in this study. Firstly, the lipid component of egg yolk powder gel and the correlation between the gel strength of egg yolk powder and Texture Profile Analysis were analyzed, and then the changes of oxidation products. The method of principal component analysis (PCA) was used to determine the relationship between secondary oxidation products and fatty acids content. Moreover, Redundancy analysis (RDA) was used to study the relationship between fatty acids, Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), peroxide value (POV) in Egg Yolk Gel. Result indicated, Lipid content of egg yolk powder gel was lower than egg yolk powder, the gel strength was positively correlated with hardness, adhesion, viscosity and masticatory ( p < 0.01), and had a significant negative correlation with recovery ( p < 0.01). In the nuclear magnetic map, the signal of primary oxidation product E, E-conjugate form was at 5.70 ppm, the signal of secondary oxidation product n-aldehyde was at 9.75 ppm. Combined with PCA and RDA, the results showed that the changes of fatty acid content were negatively correlated with the changes of peroxide value, while the changes of PC and PE were positively correlated, and the contents of fatty acids, PE, PI and PC were negatively correlated with the changes of POV, of which PE and POV were the most correlated.
研究领域:
食品科学
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF FOOD SCIENCE
·
2025
·Vol. 90
·期 5
·e70227
·
IF 3.4
Li-Hua Pan,Xiao-Yu Liu,Run-Hao Lan,Shui-Zhong Luo,Zhi Zheng,Xi-Yang Zhong
Sesame paste is an attractive condiment, but it is high in fat and prone to oil-sauce separation during storage. Sesame seeds were infrared roasted, pressed to remove partial oil, and then ground to produce sesame paste with 35%–55% oil content. The physicochemical properties of the partially de-oiled sesame paste, including texture, particle size distribution, rheological properties, colloidal and oxidative stability, appearance, and microstructure, were analyzed. Additionally, its antioxidant profile, comprising phenolic composition, total phenolic content, lignans content, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability, and ferric-reducing antioxidant power (FRAP), was examined. Moreover, the molecular traits of sesame paste protein isolates (SPPI) in the partially de-oiled sesame paste, such as secondary structure, surface hydrophobicity, and free sulfhydryl contents, were also analyzed. Results showed that compared to the non-infrared radiation (IR) roasted paste, the IR roasted sesame paste had a more homogeneous structure, smaller particle size, and better oxidation stability. The contents of total phenolics, sesamol, β-sheet, and free sulfhydryl groups in the IR roasted paste increased by 42.44%–81.86%, 1.12–1.48 mg/g, 18.84%–51.45%, and 20.29%–40.93%, respectively; however, the α-helix content of SPPI decreased by 42.34%–55.47%. The increase of the unfolded protein and phenolic compounds in the sesame paste may determine the rheological properties and antioxidant profiles of the IR roasted sesame paste and hence its storage stability by preventing the oil from separating and oxidizing during long-term storage. The IR roasted sesame paste with 40% oil content, labeled as SP IR 40, is acceptable for its good spreadability, appropriate fluidity, and high storage stability.
研究领域:
食品科学
·
植物化学
·
营养学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）